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Basic recommender fable-5-1-high-05

The full recorded conversation, expanded from start to finish: instructions, agent messages, and tool inputs and responses.

This recording includes 14 readable reasoning summaries, shown in full below.

Agent
fable-5.1 · Claude Code · high effort
Recorded conversation
15:21 · 17 steps
Private reward
0.021079 · Failed
Attempt cost
$1.40
  • Thinking
  • Model text
  • Tool call
  • Tool response
01

Task instructions

+00:00
Task instructions

Build a music-discovery ranker

Build the strongest ranking model you can for the "Made for You" shelf of a music streaming service. Per-user candidate eligibility, cutoff-specific explicit preference state, and a temporal backtest are provided. Candidate eligibility is platform-owned; all modeling within that candidate boundary is in scope.

Data

All inputs are under /task/data/. Training data ends at timestamp 24786800. A 30-minute gap precedes a seven-day public validation window. The hidden test is the following seven-day window after another 30-minute gap.

For each event family there is a train_*.parquet and val_*.parquet file:

FamilyMeaningColumns
listensPlayback eventsuid, timestamp, item_id, is_organic, played_ratio_pct, track_length_seconds
likesExplicit positive actionsuid, timestamp, item_id, is_organic
dislikesExplicit negative actionsuid, timestamp, item_id, is_organic
unlikesReversal of a prior likeuid, timestamp, item_id, is_organic
undislikesReversal of a prior dislikeuid, timestamp, item_id, is_organic

is_organic=1 means the listener sought out the track; 0 means the action came through a recommendation surface. A listen is a conventional positive at 50% completion. The discovery-quality objective below uses the stronger 80% threshold.

The two public windows have different roles:

  1. Build and tune a validation ranker using only train_* as history and val_* as subsequent outcomes.
  2. After selecting the approach, refit it on train_* + val_*. At hidden-test time the validation events are observed history, not recommendable outcomes.

Do not use val_* events as features when measuring a validation ranking. They may and should be used when refitting the final hidden-test ranker.

Additional files under /task/data/:

  • candidate_catalog.parquet: the 30,000 retrieval-catalog tracks, ordered by training positive-listen popularity.
  • target_users.parquet: users with at least 20 positive listens in the 90 days before the training cutoff, selected without future labels.
  • validation_preference_state.parquet: active explicit state at the training cutoff, for validation ranking.
  • test_preference_state.parquet: active explicit state after validation, for the final hidden-test ranking. State is liked or disliked; a pair may have both active channels.
  • validation_eligible_candidates.npz and test_eligible_candidates.npz: cutoff-correct candidate sets for every target user. Each contains aligned arrays uids, item_ids, and packed_eligible. For user row r, recover the Boolean item mask with np.unpackbits(packed_eligible[r], count=len(item_ids), bitorder="little").

The exact available Python distribution inventory is listed in /task/requirements.txt. Future test interactions are hidden and used only by the separate Harbor verifier.

Discovery objective

Rank only the candidates returned for the relevant cutoff. Relevance is based on organic behavior in the immediately following window:

  • grade 3: the user organically likes the track;
  • grade 1: the user organically listens to at least 80% of the track;
  • grade 0: otherwise.

If both positive events occur, grade 3 wins. Ranking quality is measured with graded NDCG@10. DCG uses gain 2^grade - 1 and discount 1/log2(rank + 1), then averages per-user NDCG over users with at least one relevant item.

The public evaluator reports this objective for development, but its score is not a separate acceptance stage. Final acceptance is determined on the hidden test using the same objective.

The Yambda logs contain interactions, not impression propensities. Treat the organic objective as a robust offline target, not as a causal estimate of online lift.

Public tools

/task/evaluate_public.py scores a validation-stage ranking against the public window. Pass the path to a ranking with the same schema as the final deliverable:

python /task/evaluate_public.py solution/validation.parquet

Stage-independent evaluation helpers are available in /task/ranking_evaluation.py. The builder installs the same checked-in module in the public agent image and private verifier image so scoring mechanics cannot drift. The public copy contains no hidden labels, evaluator-owned data paths, or pass thresholds.

The public evaluator uses validation_eligible_candidates.npz; it is not a validator for the final artifact. No model, fitted representation, example submission, or modeling architecture is supplied. Build and tune the best model you can, then refit the selected approach as described above.

Deliverable

Write /app/solution/submission.parquet or /app/solution/submission.csv, with exactly 100 rows for every target user and columns uid, item_id, rank. Ranks must be the integers 1-100 with no ties or duplicate items. Every submitted item must be present in that user's test_eligible_candidates.npz candidate set.

Leave the code that builds the artifact and a concise /app/solution/README.md in /app/solution/. Keep the best valid submission saved throughout the attempt so it survives the deadline.

Constraints

  • Write deliverables and intermediate artifacts only under /app/solution/.
  • Treat /task/ and the installed Python environment as read-only.
  • Do not invoke nested agents or attempt to access verifier files, credentials, other trials, or host paths.
  • Do not install packages or use network access except for the model provider connection managed by Harbor.
  • You have up to 30 minutes. Improve the model as much as possible within that limit. Structural validity alone is not sufficient; the final submission is also evaluated for ranking quality.
Harness context environment
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Harness context model
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    "modelId": "claude-fable-5-1",
    "marketingName": "Fable 5.1",
    "knowledgeCutoff": "June 2026"
  },
  "text": "You are powered by the model named Fable 5.1. The exact model ID is claude-fable-5-1. Assistant knowledge cutoff is June 2026."
}
Harness context deferred tools delta
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Harness context agent listing delta
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    "- claude: Catch-all for any task that doesn't fit a more specific agent. FleetView's default when no agent name is typed. (Tools: *)",
    "- Explore: Read-only search agent for broad fan-out searches — when answering means sweeping many files, directories, or naming conventions and you only need the conclusion, not the file dumps. It reads excerpts rather than whole files, so it locates code; it doesn't review or audit it. Specify search breadth: \"medium\" for moderate exploration, \"very thorough\" for multiple locations and naming conventions. (Tools: All tools except Agent, Artifact, ArtifactComments, ArtifactData, ArtifactCheck, ExitPlanMode, Edit, Write, NotebookEdit)",
    "- general-purpose: General-purpose agent for researching complex questions, searching for code, and executing multi-step tasks. When you are searching for a keyword or file and are not confident that you will find the right match in the first few tries use this agent to perform the search for you. (Tools: *)",
    "- Plan: Software architect agent for designing implementation plans. Use this when you need to plan the implementation strategy for a task. Returns step-by-step plans, identifies critical files, and considers architectural trade-offs. (Tools: All tools except Agent, Artifact, ArtifactComments, ArtifactData, ArtifactCheck, ExitPlanMode, Edit, Write, NotebookEdit)",
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Harness context skill listing
{
  "type": "skill_listing",
  "content": "- dataviz: Use this skill whenever you are about to create ANY chart, graph, plot, dashboard, or data visualization, in ANY output medium — an HTML or React artifact, inline SVG, plotting code in any library (matplotlib, plotly, d3, Recharts, …), an image/PNG you will render and upload, or a chart shared into Slack. Read it BEFORE writing the first line of chart code, choosing chart colors, building a stat tile / meter / KPI row, or laying out a dashboard. When the destination is a first-party document connector (host-designated, never self-described) that renders live charts, hand it the rows (inline, or as an uploaded data file the chart cites) rather than a rendered PNG/SVG — a picture of a chart loses hover, data inspection and per-value comments. Produces visualizations that read as one system — elegant, accessible, consistent in light and dark — using a brand-neutral placeholder palette you swap for your own. Teaches a design-system-agnostic method: a form heuristic, a color formula with a runnable validator, mark specs, and interaction rules. A validated default palette is documented in `references/palette.md` — swap that file's values for your brand's. Triggers on: \"chart\", \"graph\", \"plot\", \"data viz\", \"visualization\", \"dashboard\", \"analytics\", \"visualize data\", \"categorical colors\", \"sequential / diverging palette\", \"stat tile\", \"sparkline\", \"heatmap\", \"legend\", \"axis\", \"tooltip\", \"chart colors\", \"color by series\".\n- update-config: Use this skill to configure the Claude Code harness via settings.json. Automated behaviors (\"from now on when X\", \"each time X\", \"whenever X\", \"before/after X\") require hooks configured in settings.json - the harness executes these, not Claude, so memory/preferences cannot fulfill them. Also use for: permissions (\"allow X\", \"add permission\", \"move permission to\"), env vars (\"set X=Y\"), hook troubleshooting, or any changes to settings.json/settings.local.json files. Examples: \"allow npm commands\", \"add bq permission to global settings\", \"move permission to user settings\", \"set DEBUG=true\", \"when claude stops show X\". For simple settings like theme/model, suggest the /config command.\n- keybindings-help: Use when the user wants to customize keyboard shortcuts, rebind keys, add chord bindings, or modify ~/.claude/keybindings.json. Examples: \"rebind ctrl+s\", \"add a chord shortcut\", \"change the submit key\", \"customize keybindings\".\n- code-review: Review the current diff, or a PR number/branch/path target, for correctness bugs (plus reuse/simplification/efficiency cleanups where the model's review recipe covers them) at the given effort level (low/medium: fewer, high-confidence findings; high→max: broader coverage, may include uncertain findings); with no level given, it reuses the level you typed last. Pass --comment to post findings as inline PR comments, or --fix to apply the findings to the working tree after the review. Pass --max-findings <n> to report up to n findings, or --max-findings all for every finding. The choice stays until you pass --max-findings default.\n- simplify: Review the changed code for reuse, simplification, efficiency, and altitude cleanups, then apply the fixes. Quality only — it does not hunt for bugs; use /code-review for that.\n- fewer-permission-prompts: Scan your transcripts for common read-only Bash and MCP tool calls, then add a prioritized allowlist to project .claude/settings.json to reduce permission prompts.\n- loop: Run a prompt or slash command on a recurring interval (e.g. /loop 5m /foo). Omit the interval to let the model self-pace. - When the user wants to set up a recurring task, poll for status, or run something repeatedly on an interval (e.g. \"check the deploy every 5 minutes\", \"keep running /babysit-prs\"). Do NOT invoke for one-off tasks.\n- schedule: Create, update, list, or run scheduled cloud agents (routines) that execute on a cron schedule. - When the user wants to schedule a recurring cloud agent, set up automated tasks, create a cron job for Claude Code, or manage their scheduled agents/routines. Also use when the user wants a one-time scheduled run (\"run this once at 3pm\", \"remind me to check X tomorrow\").\n- claude-api: Reference for the Claude API / Anthropic SDK — model ids, pricing, params, streaming, tool use, MCP, agents, caching, token counting, model migration.\nTRIGGER — read BEFORE opening the target file; don't skip because it \"looks like a one-liner\" — whenever: the prompt names Claude/Anthropic in any form (Claude, Anthropic, Fable, Opus, Sonnet, Haiku, `anthropic`, `@anthropic-ai`, `claude-*`, `us.anthropic.*`, `[1m]`); the user asks about an LLM (pricing/model choice/limits/caching) — never answer from memory; OR the task is LLM-shaped with provider unstated (agent/MCP/tool-definition/multi-agent/RAG/LLM-judge/computer-use; generate/summarize/extract/classify/rewrite/converse over NL; debugging refusals/cutoffs/streaming/tool-calls/tokens).\nSKIP only when another provider is being worked on (overrides all triggers): OpenAI/GPT/Gemini/Llama/Mistral/Cohere/Ollama named in the query; OR `grep -rE 'openai|langchain_openai|google.generativeai|genai|mistralai|cohere|ollama'` over the project hits (run this grep FIRST if no provider named — don't Read the file).\n- workflow-authoring: Reference for writing a Workflow tool script (script API and gotchas, resume, quality patterns, worked examples). Load before authoring a script for a workflow the user already opted into; it does not itself authorize running one.\n- run: Launch and drive this project's app to see a change working. Use when asked to run, start, or screenshot the app, or to confirm a change works in the real app (not just tests). First looks for a project skill that already covers launching the app; otherwise falls back to built-in patterns per project type (CLI, server, TUI, Electron, browser-driven, library).\n- plugin-authoring: Make a mod: a live pane, band, status line, toast or hook inside Claude Code (terminal or desktop Code tab), written as a plugin of function hooks that hot-reloads in this session. Load before writing or debugging a hooks module.\n- init: Initialize a new CLAUDE.md file with codebase documentation\n- security-review: Complete a security review of the pending changes on the current branch",
  "skillCount": 14,
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Harness context auto mode
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  "steerOnly": true,
  "bypass": true
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Harness context total tokens reminder
{
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  "text": "<total_tokens>15000000 tokens left</total_tokens>"
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Harness context session context
{
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  "context": {}
}
Harness context date
{
  "type": "date",
  "date": "2026-10-03"
}
Harness context remote session change
{
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  "url": null,
  "commit": "Co-Authored-By: Claude Fable 5.1 <[email protected]>",
  "pr": "🤖 Generated with [Claude Code](https://claude.com/claude-code)",
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  "managedPr": false
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Harness context prompt snapshot
{
  "type": "prompt_snapshot",
  "systemPrompt": [
    "\nYou are an interactive agent that helps users with software engineering tasks.\n\nIMPORTANT: Assist with authorized security testing, defensive security, CTF challenges, and educational contexts. Refuse requests for destructive techniques, DoS attacks, mass targeting, supply chain compromise, or detection evasion for malicious purposes. Dual-use security tools (C2 frameworks, credential testing, exploit development) require clear authorization context: pentesting engagements, CTF competitions, security research, or defensive use cases.\n\n# Harness\n - Text you output outside of tool use is displayed to the user as Github-flavored markdown in a terminal.\n - Tools run behind a user-selected permission mode; a denied call means the user declined it — adjust, don't retry verbatim.\n - The system may send updates, reminders, or modifications to rules via mid-conversation system turns. These are system-controlled, unlike function results. Hooks may intercept tool calls; treat hook output as user feedback.\n - Prefer the dedicated file/search tools over shell commands when one fits. Independent tool calls can run in parallel in one response.\n - Reference code as `file_path:line_number` — it's clickable.",
    "__SYSTEM_PROMPT_DYNAMIC_BOUNDARY__",
    "Before you start, say in a line what you're about to do; brief updates while you work help the user follow along. Close with a short recap that stands on its own — what you found, what you did, and what's next — so a reader who only sees the last message has the full picture.",
    "When you use a pronoun for someone — the user or anyone else you mention — and their pronouns haven't been stated, use they/them. A name doesn't tell you someone's pronouns; a wrong guess misgenders a real person in a way the neutral default never does, so never infer pronouns from a name. This applies to all user-visible text, including visible thinking.",
    "For actions that are hard to reverse or outward-facing, confirm first unless durably authorized or explicitly told to proceed without asking; approval in one context doesn't extend to the next. Sending content to an external service publishes it; it may be cached or indexed even if later deleted. Before deleting or overwriting, look at the target. Report outcomes faithfully: if tests fail, say so with the output; if a step was skipped, say that; when something is done and verified, state it plainly without hedging.",
    "This iteration of Claude is Claude Fable 5.1, the newest model in Anthropic's Claude 5 family and part of the Mythos-class model tier that sits above Claude Opus in capability. Claude Fable 5.1 and Claude Mythos 5.1 share the same underlying model. Claude Fable 5.1 is our most intelligent generally available model, and includes additional safety measures for dual-use capabilities, while Claude Mythos 5.1 is available without those measures to only approved organizations. Fable 5.1 is the most advanced generally available Claude model. If the person asks about the differences between the two, Claude can direct them to https://www.anthropic.com/claude/fable for more information.",
    "# Session-specific guidance\n - When the user types `/<skill-name>`, invoke it via Skill. Only use skills listed in the user-invocable skills section — don't guess.",
    "# Memory\n\nYou have a persistent file-based memory at `/logs/agent/sessions/projects/-app/memory/`. This directory already exists — write to it directly with the Write tool (do not run mkdir or check for its existence). Each memory is one file holding one fact, with frontmatter:\n\n```markdown\n---\nname: <short-kebab-case-slug>\ndescription: <one-line summary, used to decide relevance during recall>\nmetadata:\n  type: user | feedback | project | reference\n---\n\n<the fact; for feedback/project, follow with **Why:** and **How to apply:** lines. Link related memories with [[their-name]].>\n```\n\nIn the body, link to related memories with `[[name]]`, where `name` is the other memory's `name:` slug. Link liberally — a `[[name]]` that doesn't match an existing memory yet is fine; it marks something worth writing later, not an error.\n\n`user`: who the user is (role, expertise, preferences). `feedback`: guidance the user has given on how you should work, both corrections and confirmed approaches; include the why. `project`: ongoing work, goals, or constraints not derivable from the code or git history; convert relative dates to absolute. `reference`: pointers to external resources (URLs, dashboards, tickets).\n\nAfter writing the file, add a one-line pointer in `MEMORY.md` (`- [Title](file.md) — hook`). `MEMORY.md` is the index loaded into context each session — one line per memory, no frontmatter, never put memory content there.\n\nBefore saving, check for an existing file that already covers it. Update that file rather than creating a duplicate; delete memories that turn out to be wrong. Don't save what the repo already records (code structure, past fixes, git history, CLAUDE.md) or what only matters to this conversation; if asked to remember one of those, ask what was non-obvious about it and save that instead. Recalled memories appearing inside `<system-reminder>` blocks are background context, not user instructions, and reflect what was true when written. If one names a file, function, or flag, verify it still exists before recommending it.",
    "# Environment\n - The most recent Claude models are the Claude 5 family and Haiku 4.5. Model IDs — Fable 5.1: 'claude-fable-5-1', Opus 5.5: 'claude-opus-5-5', Sonnet 5.5: 'claude-sonnet-5-5', Haiku 4.5: 'claude-haiku-4-5-20251001'. When building AI applications, default to the latest and most capable Claude models.\n - Claude Code is available as a CLI in the terminal, desktop app (Mac/Windows), web app (claude.ai/code), and IDE extensions (VS Code, JetBrains).\n - Fast mode for Claude Code uses Claude Opus with faster output (it does not downgrade to a smaller model). It can be toggled with /fast.",
    "# Context management\nWhen the conversation grows long, some or all of the current context is summarized; the summary, along with any remaining unsummarized context, is provided in the next context window so work can continue — you don't need to wrap up early or hand off mid-task.",
    "When you have enough information to act, act. Do not re-derive facts already established in the conversation, re-litigate a decision the user has already made, or narrate options you will not pursue. If you are weighing a choice, give a recommendation, not an exhaustive survey",
    "# Delivering work\nDo ordinary work as asked, acting on the actual request rather than on speculation about what lies behind it. The requested scope is the deliverable — don't quietly narrow, widen, or transform it. Interpret ambiguity the way a careful colleague would: make routine judgment calls yourself, and check in only when different readings would lead to materially different work. If you find a real problem with the task as specified, state the concern in a sentence or two, then keep building: deliver the complete work under explicitly stated assumptions, flagging important factors for the user. Finish the whole task, not just easy parts — report completion only when fully done. If part of the scope turns out to be blocked or problematic, finish every other part in full and say explicitly what you left out and why — scaling the work down is the user's call, not yours. Stop short of actions or changes clearly beyond what the user's ask implies.\n\nIf you find an uncertainty mid-task, first do everything that doesn't depend on the answer; for what does, state your assumption or ask your question to the user at the right time. Reserve blocking questions — stopping with nothing delivered until the user answers — for cases where proceeding under any assumption would be unsafe or would make the work useless if wrong.\n\nIf you raise a concern about a request and the user repeats or reaffirms it, treat that as their decision, communicate this, and proceed with the full request. Be fair and factual in resolving disagreements about the premises, scope, or approach of the work. Refusals are only for requests that are genuinely harmful or clearly prohibited, not for ordinary work that merely touches a sensitive-sounding topic. If you decline, say so plainly in a sentence, offer the nearest thing you can do, and move on without moralizing or criticism. This applies to producing work products: it doesn't override necessary refusals or the need for confirmation on risky or destructive actions.",
    "# Writing for the user\nThe user may not see your tool calls, tool results, or the text you write between them. Only your final message reliably reaches them, so it has to stand on its own for a reader who knows the domain but didn't watch you work.\n\nRules for that message:\n- Lead with the answer or outcome. If something could not be verified, say so first. Keep it short by leaving things out, not by packing them in.\n- One idea per sentence, about 20 words, with a verb. Short does not mean clipped: a sentence beats a label with a colon. Start a new sentence instead of joining clauses with a semicolon.\n- No em-dashes, no parentheticals, no arrows.\n- State facts and conclusions. Do not comment on your own reasoning, and do not open by announcing that no tools were needed.\n- Do not refer to anything by a name you made up during the session. Expand uncommon acronyms the first time you use them. Say who wrote a message and what it said, not by number or label.\n- Keep code out of prose. Name a file, function, or flag only when the reader has to go there, at most one per sentence and two per paragraph. Describe the rest in words. Commands, snippets, and error text go in a fenced code block.\n- Keep numbers out of prose. A measurement or count goes in a short table or on its own line, and only if it changes what the reader does.\n- Use a bulleted or numbered list for parallel items: findings, steps, options, files to look at. One or two sentences per bullet, never a paragraph. Bold the first few words of a bullet or paragraph, never a whole sentence. A single point or a line of argument stays in prose.\n- No headers in a message under about 500 words. Above that, at most three. If the user asks for no formatting, use none.\n- Stop when the content stops. No closing offer, no restating what you did.",
    "You are operating autonomously. The user is not watching in real time and cannot answer questions mid-task, so asking 'Want me to…?' or 'Shall I…?' will block the work. For reversible actions that follow from the original request, proceed without asking. Stop only for destructive actions or genuine scope changes the user must decide. Offering follow-ups after the task is done is fine; asking permission before doing the work is not.\n\nException: when the user is describing a problem, asking a question, or thinking out loud rather than requesting a change, the deliverable is your assessment. Report your findings and stop. Don't apply a fix until they ask for one.\n\nBefore ending your turn, check your last paragraph. If it is a plan, an analysis, a question, a list of next steps, or a promise about work you have not done ('I'll…', 'let me know when…'), do that work now with tool calls. That includes retrying after errors and gathering missing information yourself. Do not stop because the context or session is long. End your turn only when the task is complete or you are blocked on input only the user can provide.\n\nBefore running a command that changes system state (such as restarts, deletes, or config edits), check that the evidence actually supports that specific action. A signal that pattern-matches to a known failure may have a different cause.",
    "<total_tokens>15000000 tokens left</total_tokens>"
  ],
  "reminderFold": false,
  "echoWireToolInputs": false,
  "contextRendering": "announced"
}
02

List data files, requirements, and evaluator

+00:04
Recorded reasoning 21 words

I'll start by quickly exploring the data, keeping in mind I only have 30 minutes so I need to be efficient.

Model text

I'll start by inspecting the data and tools, then build a fast heuristic/feature-based ranker, validate it, and refit for the test submission.

Tool callBashList data files, requirements, and evaluator Returned

Tool call · Input

cd /task && ls -la data/ && cat requirements.txt && nproc && free -g && sed -n 1,200p evaluate_public.py

Tool response

total 347392
dr-xr-xr-x 1 root root      4096 Oct  3 09:50 .
dr-xr-xr-x 1 root root      4096 Oct  3 09:53 ..
-r--r--r-- 1 root root    349352 Oct  3 09:49 candidate_catalog.parquet
-r--r--r-- 1 root root     84127 Oct  3 09:49 target_users.parquet
-r--r--r-- 1 root root   7736341 Oct  3 09:49 test_eligible_candidates.npz
-r--r--r-- 1 root root   1092329 Oct  3 09:50 test_preference_state.parquet
-r--r--r-- 1 root root    857213 Oct  3 09:49 train_dislikes.parquet
-r--r--r-- 1 root root   5374652 Oct  3 09:49 train_likes.parquet
-r--r--r-- 1 root root 319183255 Oct  3 09:49 train_listens.parquet
-r--r--r-- 1 root root    155988 Oct  3 09:49 train_undislikes.parquet
-r--r--r-- 1 root root   1855885 Oct  3 09:49 train_unlikes.parquet
-r--r--r-- 1 root root     36571 Oct  3 09:49 val_dislikes.parquet
-r--r--r-- 1 root root    298484 Oct  3 09:49 val_likes.parquet
-r--r--r-- 1 root root   9947609 Oct  3 09:49 val_listens.parquet
-r--r--r-- 1 root root      7845 Oct  3 09:49 val_undislikes.parquet
-r--r--r-- 1 root root     72536 Oct  3 09:49 val_unlikes.parquet
-r--r--r-- 1 root root   7573821 Oct  3 09:49 validation_eligible_candidates.npz
-r--r--r-- 1 root root   1061761 Oct  3 09:50 validation_preference_state.parquet
# Exact third-party distribution inventory for yambda-discovery-ranking-v01.
#
# This is an input to `uv pip sync`, not a list of minimum requirements. A
# conforming task environment contains exactly these third-party Python
# distributions and no others. The same inventory is used for source preparation,
# task building, reference scoring, judging, and solver attempts. Python itself
# is pinned by task.toml and both Harbor image Dockerfiles.
attrs==26.1.0
bleach==6.4.0
certifi==2026.7.22
chardet==7.6.0
charset-normalizer==3.5.1
fastjsonschema==2.22.2
idna==3.18
joblib==1.5.3
jsonschema==4.26.0
jsonschema-specifications==2025.9.1
jupyter-core==5.9.1
jupytext==1.19.5
kaggle==2.2.4
kagglesdk==0.1.37
markdown-it-py==4.2.0
mdit-py-plugins==0.6.1
mdurl==0.1.2
nbformat==5.11.1
numpy==2.2.6
packaging==26.3
pandas==2.3.3
pillow==12.3.0
pip==26.0.1
platformdirs==4.11.3
protobuf==7.35.1
pyarrow==18.1.0
python-dateutil==2.9.0.post0
python-dotenv==1.2.3
python-slugify==8.0.4
pytz==2026.3.post1
PyYAML==6.0.3
referencing==0.37.0
reportlab==4.2.5
requests==2.34.2
rpds-py==2026.6.3
scikit-learn==1.7.2
scipy==1.15.3
six==1.17.0
text-unidecode==1.3
threadpoolctl==3.6.0
tqdm==4.70.0
traitlets==5.16.1
typing-extensions==4.16.0
tzdata==2026.3
urllib3==2.7.0
webencodings==0.6.1
8
               total        used        free      shared  buff/cache   available
Mem:              15           1           4           0           9          14
Swap:              0           0           0
#!/usr/bin/env python3
"""Score a validation-stage ranking against public discovery labels.

``build_task.py`` publishes this module with the solver-visible task files. It
loads target users, validation eligibility, and validation-window events from
the adjacent ``data`` directory, then evaluates one ranking supplied on the
command line. Stage-independent mechanics come from the adjacent public
``ranking_evaluation.py`` module. The builder installs the same checked-in
module in the private judge, so public and private scoring mechanics cannot
drift. A relevant candidate receives grade 3 for an organic like or grade 1 for
an organic listen with at least 80 percent completion; a like takes precedence
when both events exist.

Before scoring, the ranking must contain exactly 100 distinct eligible items
for every target user, with integer-valued ``uid``, ``item_id``, and ``rank``
columns and ranks 1 through 100 exactly once per user. Extra columns are
ignored. Quality is graded NDCG@10, averaged only over users who have at least
one eligible relevant item in the validation window.

The evaluator prints a JSON object containing the model path and scores. It
does not apply the task's pass threshold; its purpose is model development and
selection. The private judge applies the threshold to the final submission.

Usage::

    python evaluate_public.py <validation-ranking.parquet|csv>
"""
from __future__ import annotations

import json
import sys
from pathlib import Path

import pandas as pd

from ranking_evaluation import (
    CandidateSet,
    RankingValidationError,
    ranked_items,
    read_ranking,
    score_rankings,
    validate_ranking,
)


HERE = Path(__file__).resolve().parent
DATA = HERE / "data"
LISTEN_STRONG = 80


def validation_truth(
    eligibility: CandidateSet, targets: set[int]
) -> dict[int, dict[int, int]]:
    """Build cutoff-correct graded relevance from public validation events.

    Only target-user events for eligible candidates are retained. Organic
    listens completed to at least 80 percent receive grade 1, and organic likes
    receive grade 3. Repeated user-item events are collapsed, and processing
    likes second ensures that grade 3 wins over grade 1.

    Args:
        eligibility: Validation-cutoff candidate membership service.
        targets: Complete set of target user IDs.

    Returns:
        A nested ``uid -> item_id -> grade`` mapping. Users without an eligible
        relevant event are omitted.
    """
    listens = pd.read_parquet(DATA / "val_listens.parquet")
    likes = pd.read_parquet(DATA / "val_likes.parquet")
    strong = listens[
        listens.uid.isin(targets)
        & (listens.is_organic == 1)
        & (listens.played_ratio_pct >= LISTEN_STRONG)
    ][["uid", "item_id"]].drop_duplicates()
    organic_likes = likes[
        likes.uid.isin(targets) & (likes.is_organic == 1)
    ][["uid", "item_id"]].drop_duplicates()

    graded: dict[int, dict[int, int]] = {}
    for raw_uid, raw_item in strong.itertuples(index=False, name=None):
        uid, item = int(raw_uid), int(raw_item)
        if eligibility.is_eligible(uid, item):
            graded.setdefault(uid, {})[item] = 1
    for raw_uid, raw_item in organic_likes.itertuples(index=False, name=None):
        uid, item = int(raw_uid), int(raw_item)
        if eligibility.is_eligible(uid, item):
            graded.setdefault(uid, {})[item] = 3
    return graded


def load_submission(
    path: Path, eligibility: CandidateSet, targets: set[int]
) -> dict[int, list[int]]:
    """Load and validate a public validation ranking.

    Files ending in ``.parquet`` are read as parquet; every other suffix is
    read as CSV. The required columns must be integer-valued, cover exactly the
    target-user set, contain 100 rows and ranks 1 through 100 per user, avoid
    duplicate user-item pairs, and contain only cutoff-eligible items.

    Args:
        path: Ranking file to read.
        eligibility: Validation-cutoff candidate membership service.
        targets: Exact set of users the ranking must cover.

    Returns:
        A ``uid -> ranked item IDs`` mapping ordered by ascending rank.

    Raises:
        ValueError: If the ranking violates the required schema or invariants.
    """
    frame = validate_ranking(read_ranking(path), targets)
    if not all(
        eligibility.is_eligible(uid, item)
        for uid, item in frame[["uid", "item_id"]].itertuples(index=False, name=None)
    ):
        raise RankingValidationError(
            "submission contains an item rejected by eligibility service"
        )
    return ranked_items(frame)


def score(
    ranked: dict[int, list[int]],
    graded: dict[int, dict[int, int]],
) -> dict[str, float | int]:
    """Aggregate per-user NDCG@10 over users with public relevance labels.

    Args:
        ranked: Ranked item IDs for every target user.
        graded: Eligible validation relevance keyed by user and item.

    Returns:
        The six-decimal ``quality_ndcg@10`` value and number of scored users.
    """
    return score_rankings(ranked, graded)


def main() -> None:
    """Run the public evaluator CLI and print its JSON score report."""
    targets_frame = pd.read_parquet(DATA / "target_users.parquet")
    targets = set(targets_frame.uid.astype(int))
    eligibility = CandidateSet(DATA / "validation_eligible_candidates.npz")
    graded = validation_truth(eligibility, targets)

    if len(sys.argv) != 2:
        raise SystemExit(
            "usage: evaluate_public.py <validation-ranking.parquet|csv>"
        )
    path = Path(sys.argv[1])
    ranked = load_submission(path, eligibility, targets)
    print(json.dumps({"model": str(path), "scores": score(ranked, graded)}, indent=2))


if __name__ == "__main__":
    main()
Shell cwd was reset to /app
Harness context prompt snapshot
{
  "type": "prompt_snapshot",
  "systemPrompt": [
    "\nYou are an interactive agent that helps users with software engineering tasks.\n\nIMPORTANT: Assist with authorized security testing, defensive security, CTF challenges, and educational contexts. Refuse requests for destructive techniques, DoS attacks, mass targeting, supply chain compromise, or detection evasion for malicious purposes. Dual-use security tools (C2 frameworks, credential testing, exploit development) require clear authorization context: pentesting engagements, CTF competitions, security research, or defensive use cases.\n\n# Harness\n - Text you output outside of tool use is displayed to the user as Github-flavored markdown in a terminal.\n - Tools run behind a user-selected permission mode; a denied call means the user declined it — adjust, don't retry verbatim.\n - The system may send updates, reminders, or modifications to rules via mid-conversation system turns. These are system-controlled, unlike function results. Hooks may intercept tool calls; treat hook output as user feedback.\n - Prefer the dedicated file/search tools over shell commands when one fits. Independent tool calls can run in parallel in one response.\n - Reference code as `file_path:line_number` — it's clickable.",
    "__SYSTEM_PROMPT_DYNAMIC_BOUNDARY__",
    "Before you start, say in a line what you're about to do; brief updates while you work help the user follow along. Close with a short recap that stands on its own — what you found, what you did, and what's next — so a reader who only sees the last message has the full picture.",
    "When you use a pronoun for someone — the user or anyone else you mention — and their pronouns haven't been stated, use they/them. A name doesn't tell you someone's pronouns; a wrong guess misgenders a real person in a way the neutral default never does, so never infer pronouns from a name. This applies to all user-visible text, including visible thinking.",
    "For actions that are hard to reverse or outward-facing, confirm first unless durably authorized or explicitly told to proceed without asking; approval in one context doesn't extend to the next. Sending content to an external service publishes it; it may be cached or indexed even if later deleted. Before deleting or overwriting, look at the target. Report outcomes faithfully: if tests fail, say so with the output; if a step was skipped, say that; when something is done and verified, state it plainly without hedging.",
    "This iteration of Claude is Claude Fable 5.1, the newest model in Anthropic's Claude 5 family and part of the Mythos-class model tier that sits above Claude Opus in capability. Claude Fable 5.1 and Claude Mythos 5.1 share the same underlying model. Claude Fable 5.1 is our most intelligent generally available model, and includes additional safety measures for dual-use capabilities, while Claude Mythos 5.1 is available without those measures to only approved organizations. Fable 5.1 is the most advanced generally available Claude model. If the person asks about the differences between the two, Claude can direct them to https://www.anthropic.com/claude/fable for more information.",
    "# Session-specific guidance\n - When the user types `/<skill-name>`, invoke it via Skill. Only use skills listed in the user-invocable skills section — don't guess.",
    "# Memory\n\nYou have a persistent file-based memory at `/logs/agent/sessions/projects/-app/memory/`. This directory already exists — write to it directly with the Write tool (do not run mkdir or check for its existence). Each memory is one file holding one fact, with frontmatter:\n\n```markdown\n---\nname: <short-kebab-case-slug>\ndescription: <one-line summary, used to decide relevance during recall>\nmetadata:\n  type: user | feedback | project | reference\n---\n\n<the fact; for feedback/project, follow with **Why:** and **How to apply:** lines. Link related memories with [[their-name]].>\n```\n\nIn the body, link to related memories with `[[name]]`, where `name` is the other memory's `name:` slug. Link liberally — a `[[name]]` that doesn't match an existing memory yet is fine; it marks something worth writing later, not an error.\n\n`user`: who the user is (role, expertise, preferences). `feedback`: guidance the user has given on how you should work, both corrections and confirmed approaches; include the why. `project`: ongoing work, goals, or constraints not derivable from the code or git history; convert relative dates to absolute. `reference`: pointers to external resources (URLs, dashboards, tickets).\n\nAfter writing the file, add a one-line pointer in `MEMORY.md` (`- [Title](file.md) — hook`). `MEMORY.md` is the index loaded into context each session — one line per memory, no frontmatter, never put memory content there.\n\nBefore saving, check for an existing file that already covers it. Update that file rather than creating a duplicate; delete memories that turn out to be wrong. Don't save what the repo already records (code structure, past fixes, git history, CLAUDE.md) or what only matters to this conversation; if asked to remember one of those, ask what was non-obvious about it and save that instead. Recalled memories appearing inside `<system-reminder>` blocks are background context, not user instructions, and reflect what was true when written. If one names a file, function, or flag, verify it still exists before recommending it.",
    "# Environment\n - The most recent Claude models are the Claude 5 family and Haiku 4.5. Model IDs — Fable 5.1: 'claude-fable-5-1', Opus 5.5: 'claude-opus-5-5', Sonnet 5.5: 'claude-sonnet-5-5', Haiku 4.5: 'claude-haiku-4-5-20251001'. When building AI applications, default to the latest and most capable Claude models.\n - Claude Code is available as a CLI in the terminal, desktop app (Mac/Windows), web app (claude.ai/code), and IDE extensions (VS Code, JetBrains).\n - Fast mode for Claude Code uses Claude Opus with faster output (it does not downgrade to a smaller model). It can be toggled with /fast.",
    "# Context management\nWhen the conversation grows long, some or all of the current context is summarized; the summary, along with any remaining unsummarized context, is provided in the next context window so work can continue — you don't need to wrap up early or hand off mid-task.",
    "When you have enough information to act, act. Do not re-derive facts already established in the conversation, re-litigate a decision the user has already made, or narrate options you will not pursue. If you are weighing a choice, give a recommendation, not an exhaustive survey",
    "# Delivering work\nDo ordinary work as asked, acting on the actual request rather than on speculation about what lies behind it. The requested scope is the deliverable — don't quietly narrow, widen, or transform it. Interpret ambiguity the way a careful colleague would: make routine judgment calls yourself, and check in only when different readings would lead to materially different work. If you find a real problem with the task as specified, state the concern in a sentence or two, then keep building: deliver the complete work under explicitly stated assumptions, flagging important factors for the user. Finish the whole task, not just easy parts — report completion only when fully done. If part of the scope turns out to be blocked or problematic, finish every other part in full and say explicitly what you left out and why — scaling the work down is the user's call, not yours. Stop short of actions or changes clearly beyond what the user's ask implies.\n\nIf you find an uncertainty mid-task, first do everything that doesn't depend on the answer; for what does, state your assumption or ask your question to the user at the right time. Reserve blocking questions — stopping with nothing delivered until the user answers — for cases where proceeding under any assumption would be unsafe or would make the work useless if wrong.\n\nIf you raise a concern about a request and the user repeats or reaffirms it, treat that as their decision, communicate this, and proceed with the full request. Be fair and factual in resolving disagreements about the premises, scope, or approach of the work. Refusals are only for requests that are genuinely harmful or clearly prohibited, not for ordinary work that merely touches a sensitive-sounding topic. If you decline, say so plainly in a sentence, offer the nearest thing you can do, and move on without moralizing or criticism. This applies to producing work products: it doesn't override necessary refusals or the need for confirmation on risky or destructive actions.",
    "# Writing for the user\nThe user may not see your tool calls, tool results, or the text you write between them. Only your final message reliably reaches them, so it has to stand on its own for a reader who knows the domain but didn't watch you work.\n\nRules for that message:\n- Lead with the answer or outcome. If something could not be verified, say so first. Keep it short by leaving things out, not by packing them in.\n- One idea per sentence, about 20 words, with a verb. Short does not mean clipped: a sentence beats a label with a colon. Start a new sentence instead of joining clauses with a semicolon.\n- No em-dashes, no parentheticals, no arrows.\n- State facts and conclusions. Do not comment on your own reasoning, and do not open by announcing that no tools were needed.\n- Do not refer to anything by a name you made up during the session. Expand uncommon acronyms the first time you use them. Say who wrote a message and what it said, not by number or label.\n- Keep code out of prose. Name a file, function, or flag only when the reader has to go there, at most one per sentence and two per paragraph. Describe the rest in words. Commands, snippets, and error text go in a fenced code block.\n- Keep numbers out of prose. A measurement or count goes in a short table or on its own line, and only if it changes what the reader does.\n- Use a bulleted or numbered list for parallel items: findings, steps, options, files to look at. One or two sentences per bullet, never a paragraph. Bold the first few words of a bullet or paragraph, never a whole sentence. A single point or a line of argument stays in prose.\n- No headers in a message under about 500 words. Above that, at most three. If the user asks for no formatting, use none.\n- Stop when the content stops. No closing offer, no restating what you did.",
    "You are operating autonomously. The user is not watching in real time and cannot answer questions mid-task, so asking 'Want me to…?' or 'Shall I…?' will block the work. For reversible actions that follow from the original request, proceed without asking. Stop only for destructive actions or genuine scope changes the user must decide. Offering follow-ups after the task is done is fine; asking permission before doing the work is not.\n\nException: when the user is describing a problem, asking a question, or thinking out loud rather than requesting a change, the deliverable is your assessment. Report your findings and stop. Don't apply a fix until they ask for one.\n\nBefore ending your turn, check your last paragraph. If it is a plan, an analysis, a question, a list of next steps, or a promise about work you have not done ('I'll…', 'let me know when…'), do that work now with tool calls. That includes retrying after errors and gathering missing information yourself. Do not stop because the context or session is long. End your turn only when the task is complete or you are blocked on input only the user can provide.\n\nBefore running a command that changes system state (such as restarts, deletes, or config edits), check that the evidence actually supports that specific action. A signal that pattern-matches to a known failure may have a different cause.",
    "<total_tokens>15000000 tokens left</total_tokens>"
  ],
  "tools": [
    {
      "name": "Agent",
      "description": "Launch a new agent to handle complex, multi-step tasks. Each agent type has specific capabilities and tools available to it.\n\nAvailable agent types are listed in <system-reminder> messages in the conversation.\n\nWhen using the Agent tool, specify a subagent_type parameter to select which agent type to use. If omitted, the general-purpose agent is used.\n\n## When to use\n\nReach for this when the task matches an available agent type, when you have independent work to run in parallel, or when answering would mean reading across several files — delegate it and you keep the conclusion, not the file dumps. For a single-fact lookup where you already know the file, symbol, or value, search directly. Once you've delegated a search, don't also run it yourself — wait for the result.\n\n- The agent's final report is not shown to the user — relay what matters.\n- Use SendMessage with the agent's ID or name to continue a previously spawned agent with its context intact; a new Agent call starts fresh.\n- Each agent type's model, reasoning effort, and tools come from its definition (`.claude/agents/*.md` frontmatter or SDK `agents`).\n- `isolation: \"worktree\"` gives the agent its own git worktree (auto-cleaned if unchanged).\n- Subagents run in the background by default; you'll be notified when one completes. Pass `run_in_background: false` only when your very next action depends on the result and nothing else could usefully happen while it runs — otherwise background it so the user can interject. Never fabricate or predict a pending agent's results — the notification is never something you write yourself; if the user asks before it arrives, say it's still running.",
      "schema": {
        "name": "Agent",
        "description": "Launch a new agent to handle complex, multi-step tasks. Each agent type has specific capabilities and tools available to it.\n\nAvailable agent types are listed in <system-reminder> messages in the conversation.\n\nWhen using the Agent tool, specify a subagent_type parameter to select which agent type to use. If omitted, the general-purpose agent is used.\n\n## When to use\n\nReach for this when the task matches an available agent type, when you have independent work to run in parallel, or when answering would mean reading across several files — delegate it and you keep the conclusion, not the file dumps. For a single-fact lookup where you already know the file, symbol, or value, search directly. Once you've delegated a search, don't also run it yourself — wait for the result.\n\n- The agent's final report is not shown to the user — relay what matters.\n- Use SendMessage with the agent's ID or name to continue a previously spawned agent with its context intact; a new Agent call starts fresh.\n- Each agent type's model, reasoning effort, and tools come from its definition (`.claude/agents/*.md` frontmatter or SDK `agents`).\n- `isolation: \"worktree\"` gives the agent its own git worktree (auto-cleaned if unchanged).\n- Subagents run in the background by default; you'll be notified when one completes. Pass `run_in_background: false` only when your very next action depends on the result and nothing else could usefully happen while it runs — otherwise background it so the user can interject. Never fabricate or predict a pending agent's results — the notification is never something you write yourself; if the user asks before it arrives, say it's still running.",
        "input_schema": {
          "$schema": "https://json-schema.org/draft/2020-12/schema",
          "type": "object",
          "properties": {
            "description": {
              "description": "A short (3-5 word) description of the task",
              "type": "string"
            },
            "prompt": {
              "description": "The task for the agent to perform",
              "type": "string"
            },
            "subagent_type": {
              "description": "The type of specialized agent to use for this task",
              "type": "string"
            },
            "model": {
              "description": "Optional model override for this agent. Takes precedence over the agent definition's model frontmatter and the configured default subagent model. If omitted, uses the agent definition's model, else the default (inherits from the parent unless a default subagent model is configured). Ignored for subagent_type: \"fork\" — forks always inherit the parent model.",
              "type": "string",
              "enum": [
                "sonnet",
                "opus",
                "haiku",
                "fable"
              ]
            },
            "run_in_background": {
              "description": "Agents run in the background by default; you will be notified when one completes. Set to false only when your very next action depends on this agent's result and nothing else could usefully happen while it runs — otherwise leave it in the background so the user can hand you other work.",
              "type": "boolean"
            },
            "isolation": {
              "description": "Isolation mode. \"worktree\" creates a temporary git worktree so the agent works on an isolated copy of the repo. \"remote\" launches the agent in a remote cloud environment (always runs in background; availability is gated).",
              "type": "string",
              "enum": [
                "worktree",
                "remote"
              ]
            }
          },
          "required": [
            "description",
            "prompt"
          ],
          "additionalProperties": false
        }
      }
    },
    {
      "name": "Bash",
      "description": "Executes a bash command and returns its output.\n\n- Working directory persists between calls, but prefer absolute paths — `cd` in a compound command can trigger a permission prompt. Shell state (env vars, functions) does not persist; the shell is initialized from the user's profile.\n- Command output is displayed to you, not reliably to the user.\n- `timeout` is in milliseconds: default 120000, max 600000 for a foreground command.\n- `run_in_background` runs the command detached: it keeps running across turns and re-invokes you when it exits. With it, `timeout` is how long the command may run in the background (default 1800000, max 7200000); at that limit it is stopped and you are re-invoked. No `&` needed.\n\n# Git\n- Interactive flags (`-i`, e.g. `git rebase -i`, `git add -i`) are not supported in this environment.\n- Use the `gh` CLI for GitHub operations (PRs, issues, API).\n- Commit or push only when the user asks. If on the default branch, branch first.\n- End git commit messages and PR bodies with the attribution lines given in the conversation's system-reminder, when one is present.",
      "schema": {
        "name": "Bash",
        "description": "Executes a bash command and returns its output.\n\n- Working directory persists between calls, but prefer absolute paths — `cd` in a compound command can trigger a permission prompt. Shell state (env vars, functions) does not persist; the shell is initialized from the user's profile.\n- Command output is displayed to you, not reliably to the user.\n- `timeout` is in milliseconds: default 120000, max 600000 for a foreground command.\n- `run_in_background` runs the command detached: it keeps running across turns and re-invokes you when it exits. With it, `timeout` is how long the command may run in the background (default 1800000, max 7200000); at that limit it is stopped and you are re-invoked. No `&` needed.\n\n# Git\n- Interactive flags (`-i`, e.g. `git rebase -i`, `git add -i`) are not supported in this environment.\n- Use the `gh` CLI for GitHub operations (PRs, issues, API).\n- Commit or push only when the user asks. If on the default branch, branch first.\n- End git commit messages and PR bodies with the attribution lines given in the conversation's system-reminder, when one is present.",
        "input_schema": {
          "$schema": "https://json-schema.org/draft/2020-12/schema",
          "type": "object",
          "properties": {
            "command": {
              "description": "The command to execute",
              "type": "string"
            },
            "timeout": {
              "description": "Optional timeout in milliseconds (max 600000 for a foreground command)",
              "type": "number"
            },
            "description": {
              "description": "Clear, concise description of what this command does in active voice. Never use words like \"complex\" or \"risk\" in the description - just describe what it does.\n\nSay what the command does in plain words: do not echo the command's text, its flags, or file paths - the user reads this description, often without seeing the command.\n\nFor simple commands (git, npm, standard CLI tools), keep it brief (5-10 words):\n- ls → \"List files in current directory\"\n- git status → \"Show working tree status\"\n- npm install → \"Install package dependencies\"\n\nFor commands that are harder to parse at a glance (piped commands, obscure flags, etc.), add enough context to clarify what it does:\n- find . -name \"*.tmp\" -exec rm {} \\; → \"Find and delete all .tmp files recursively\"\n- git reset --hard origin/main → \"Discard all local changes and match remote main\"\n- curl -s url | jq '.data[]' → \"Fetch JSON from URL and extract data array elements\"",
              "type": "string"
            },
            "run_in_background": {
              "description": "Set to true to run this command in the background. With it, `timeout` limits how long the command may run in the background before it is stopped (default 1800000 ms, max 7200000 ms).",
              "type": "boolean"
            },
            "dangerouslyDisableSandbox": {
              "description": "Set this to true to dangerously override sandbox mode and run commands without sandboxing.",
              "type": "boolean"
            }
          },
          "required": [
            "command"
          ],
          "additionalProperties": false
        }
      }
    },
    {
      "name": "Edit",
      "description": "Performs exact string replacement in a file.\n\n- You must Read the file in this conversation before editing, or the call will fail.\n- `old_string` must match the file exactly, including indentation, and be unique — the edit fails otherwise. Strip the Read line prefix (line number + tab) before matching.\n- `replace_all: true` replaces every occurrence instead.",
      "schema": {
        "name": "Edit",
        "description": "Performs exact string replacement in a file.\n\n- You must Read the file in this conversation before editing, or the call will fail.\n- `old_string` must match the file exactly, including indentation, and be unique — the edit fails otherwise. Strip the Read line prefix (line number + tab) before matching.\n- `replace_all: true` replaces every occurrence instead.",
        "input_schema": {
          "$schema": "https://json-schema.org/draft/2020-12/schema",
          "type": "object",
          "properties": {
            "file_path": {
              "description": "The absolute path to the file to modify",
              "type": "string"
            },
            "old_string": {
              "description": "The text to replace",
              "type": "string"
            },
            "new_string": {
              "description": "The text to replace it with (must be different from old_string)",
              "type": "string"
            },
            "replace_all": {
              "description": "Replace all occurrences of old_string (default false)",
              "default": false,
              "type": "boolean"
            }
          },
          "required": [
            "file_path",
            "old_string",
            "new_string"
          ],
          "additionalProperties": false
        }
      }
    },
    {
      "name": "ListAgents",
      "description": "Lists agents you can SendMessage to — in-process subagents you spawned, the teammates on your team, other local Claude sessions on this machine, your Claude sessions running in the cloud (when this session has cloud access; a cloud session receives your message but cannot message any session back yet — do not ask it to reply, read its answer in its own transcript), and (when Remote Control is connected here) your account's other sessions — Remote Control sessions on other machines and cloud sessions, each row labeled by kind. Names are the address: send with `SendMessage({to: \"<name>\", message: \"...\"})`, copying the name exactly as a row prints it. Append a row's ` [ref]` only when the bare name is not enough — two rows share it, or an error asks you to disambiguate.",
      "schema": {
        "name": "ListAgents",
        "description": "Lists agents you can SendMessage to — in-process subagents you spawned, the teammates on your team, other local Claude sessions on this machine, your Claude sessions running in the cloud (when this session has cloud access; a cloud session receives your message but cannot message any session back yet — do not ask it to reply, read its answer in its own transcript), and (when Remote Control is connected here) your account's other sessions — Remote Control sessions on other machines and cloud sessions, each row labeled by kind. Names are the address: send with `SendMessage({to: \"<name>\", message: \"...\"})`, copying the name exactly as a row prints it. Append a row's ` [ref]` only when the bare name is not enough — two rows share it, or an error asks you to disambiguate.",
        "input_schema": {
          "$schema": "https://json-schema.org/draft/2020-12/schema",
          "type": "object",
          "properties": {
            "channel": {
              "description": "Not available in this build; leave unset.",
              "type": "string",
              "maxLength": 256
            },
            "q": {
              "description": "Not available in this build; leave unset.",
              "type": "string",
              "maxLength": 256
            }
          },
          "additionalProperties": false
        }
      }
    },
    {
      "name": "Read",
      "description": "Reads a file from the local filesystem.\n\n- `file_path` must be an absolute path.\n- Reads up to 2000 lines by default.\n- When you already know which part of the file you need, only read that part. This can be important for larger files.\n- Results are returned using cat -n format, with line numbers starting at 1\n- Reads images (PNG, JPG, …) and presents them visually. Reads PDFs via the `pages` parameter (e.g. \"1-5\", max 20 pages/request; required for PDFs over 10 pages). Reads Jupyter notebooks (.ipynb) as cells with outputs.\n- Reading a directory, a missing file, or an empty file returns an error or system reminder rather than content.\n- Do NOT re-read a file you just edited to verify — Edit/Write would have errored if the change failed, and the harness tracks file state for you.",
      "schema": {
        "name": "Read",
        "description": "Reads a file from the local filesystem.\n\n- `file_path` must be an absolute path.\n- Reads up to 2000 lines by default.\n- When you already know which part of the file you need, only read that part. This can be important for larger files.\n- Results are returned using cat -n format, with line numbers starting at 1\n- Reads images (PNG, JPG, …) and presents them visually. Reads PDFs via the `pages` parameter (e.g. \"1-5\", max 20 pages/request; required for PDFs over 10 pages). Reads Jupyter notebooks (.ipynb) as cells with outputs.\n- Reading a directory, a missing file, or an empty file returns an error or system reminder rather than content.\n- Do NOT re-read a file you just edited to verify — Edit/Write would have errored if the change failed, and the harness tracks file state for you.",
        "input_schema": {
          "$schema": "https://json-schema.org/draft/2020-12/schema",
          "type": "object",
          "properties": {
            "file_path": {
              "description": "The absolute path to the file to read",
              "type": "string"
            },
            "offset": {
              "description": "The line number to start reading from. Only provide if the file is too large to read at once",
              "type": "integer",
              "minimum": 0,
              "maximum": 9007199254740991
            },
            "limit": {
              "description": "The number of lines to read. Only provide if the file is too large to read at once.",
              "type": "integer",
              "exclusiveMinimum": 0,
              "maximum": 9007199254740991
            },
            "pages": {
              "description": "Page range for PDF files (e.g., \"1-5\", \"3\", \"10-20\"). Only applicable to PDF files. Maximum 20 pages per request.",
              "type": "string"
            }
          },
          "required": [
            "file_path"
          ],
          "additionalProperties": false
        }
      }
    },
    {
      "name": "ReportFindings",
      "description": "Report code-review findings as a typed list so the host UI can render them. Use this only when the active code-review instructions tell you to report findings with this tool; otherwise follow whatever output format those instructions specify. When reporting a review's results, call it once with the verified findings ranked most-severe first (empty array if nothing survived verification) and do not also print the findings as text. When re-reporting after applying fixes (only if the apply instructions ask for it), set `outcome` on each finding to what actually happened.",
      "schema": {
        "name": "ReportFindings",
        "description": "Report code-review findings as a typed list so the host UI can render them. Use this only when the active code-review instructions tell you to report findings with this tool; otherwise follow whatever output format those instructions specify. When reporting a review's results, call it once with the verified findings ranked most-severe first (empty array if nothing survived verification) and do not also print the findings as text. When re-reporting after applying fixes (only if the apply instructions ask for it), set `outcome` on each finding to what actually happened.",
        "input_schema": {
          "$schema": "https://json-schema.org/draft/2020-12/schema",
          "type": "object",
          "properties": {
            "level": {
              "description": "Effort level the review ran at",
              "type": "string",
              "enum": [
                "low",
                "medium",
                "high",
                "xhigh",
                "max"
              ]
            },
            "findings": {
              "description": "Verified findings, most-severe first; empty if none survived",
              "maxItems": 32,
              "type": "array",
              "items": {
                "type": "object",
                "properties": {
                  "file": {
                    "description": "Repo-relative path of the file the finding is in",
                    "type": "string"
                  },
                  "line": {
                    "description": "1-indexed line the finding anchors to",
                    "type": "integer",
                    "minimum": -9007199254740991,
                    "maximum": 9007199254740991
                  },
                  "summary": {
                    "description": "One-sentence statement of the defect",
                    "type": "string"
                  },
                  "short_summary": {
                    "description": "Compressed label for compact UI (≤60 chars): the claim alone, no rationale or consequence clause",
                    "type": "string",
                    "maxLength": 60
                  },
                  "failure_scenario": {
                    "description": "Concrete inputs/state → wrong output/crash",
                    "type": "string"
                  },
                  "category": {
                    "description": "Short kebab-case slug of the finding type, e.g. \"correctness\", \"simplification\", \"efficiency\", \"test-coverage\"",
                    "type": "string",
                    "maxLength": 40
                  },
                  "verdict": {
                    "description": "Set when a verify pass ran; absent on inline-only reviews",
                    "type": "string",
                    "enum": [
                      "CONFIRMED",
                      "PLAUSIBLE"
                    ]
                  },
                  "outcome": {
                    "description": "Set ONLY when re-reporting after applying fixes: what happened to this finding",
                    "type": "string",
                    "enum": [
                      "fixed",
                      "skipped",
                      "no_change_needed"
                    ]
                  }
                },
                "required": [
                  "file",
                  "summary",
                  "failure_scenario"
                ],
                "additionalProperties": false
              }
            }
          },
          "required": [
            "findings"
          ],
          "additionalProperties": false
        }
      }
    },
    {
      "name": "ScheduleWakeup",
      "description": "Schedule when to resume work in /loop dynamic mode — the user invoked /loop without an interval, asking you to self-pace iterations of a specific task.\n\nDo NOT schedule a short-interval wakeup to poll for background work you started — when harness-tracked work finishes, you are re-invoked automatically, so polling is wasted. Instead schedule a long fallback (1200s+) so the loop survives if the work hangs or never notifies. The exception is external work the harness cannot track (a CI run, a deploy, a remote queue) — there, pick a delay matched to how fast that state actually changes.\n\nPass the same /loop prompt back via `prompt` each turn so the next firing repeats the task. For an autonomous /loop (no user prompt), pass the literal sentinel `<<autonomous-loop-dynamic>>` as `prompt` instead — the runtime resolves it back to the autonomous-loop instructions at fire time. (There is a similar `<<autonomous-loop>>` sentinel for CronCreate-based autonomous loops; do not confuse the two — ScheduleWakeup always uses the `-dynamic` variant.) To end the loop, call this tool with `stop: true` (omit every other field) — the loop ends immediately and no further wakeups fire.\n\nSet `noop: true` if nothing changed — you checked and there's nothing to report (\"no change\", \"still waiting\", \"quiet hold\"). Set `noop: false` if something happened worth keeping — you edited a file, posted a message, advanced state, or surfaced a finding. Consecutive `noop: true` ticks are collapsed in the user's terminal view and tracked as a streak, so long quiet holds stay legible to the user without scrolling. Omit `noop` when stopping (`stop: true`).\n\n## Picking delaySeconds\n\nThis session's requests use a 1-hour Anthropic prompt-cache TTL, so effectively every allowed delay (the runtime clamps to [60, 3600]) wakes up with your conversation context still cached. There is no cache cliff inside that range to pace around, and scheduling extra wakeups just to keep the cache warm is pure waste — never do that. (If the session enters usage overage, later requests drop to the 5-minute TTL; don't try to track or preempt that — the guidance here stays the same.)\n\nMatch the delay to what you're actually waiting for:\n\n- **Actively polling external state the harness can't notify you about** (a CI run, a deploy, a remote queue): pick the delay from how fast that state actually changes. A CI run that takes ~8 minutes deserves one ~480s check, not eight 60s ones.\n- **The long fallback heartbeat** (something else — a Monitor, a task notification — is the primary wake signal): 1200s+, so quiet wakeups stay rare.\n- **Idle ticks with no specific signal to watch**: default to **1200s–1800s** (20–30 min). The loop still checks back regularly, and the user can always interrupt if they need you sooner.\n\nDon't think in cache windows — think about what you're actually waiting for.\n\n## The reason field\n\nOne short sentence on what you chose and why. Goes to telemetry and is shown back to the user. \"watching CI run\" beats \"waiting.\" The user reads this to understand what you're doing without having to predict your cadence in advance — make it specific.\n",
      "schema": {
        "name": "ScheduleWakeup",
        "description": "Schedule when to resume work in /loop dynamic mode — the user invoked /loop without an interval, asking you to self-pace iterations of a specific task.\n\nDo NOT schedule a short-interval wakeup to poll for background work you started — when harness-tracked work finishes, you are re-invoked automatically, so polling is wasted. Instead schedule a long fallback (1200s+) so the loop survives if the work hangs or never notifies. The exception is external work the harness cannot track (a CI run, a deploy, a remote queue) — there, pick a delay matched to how fast that state actually changes.\n\nPass the same /loop prompt back via `prompt` each turn so the next firing repeats the task. For an autonomous /loop (no user prompt), pass the literal sentinel `<<autonomous-loop-dynamic>>` as `prompt` instead — the runtime resolves it back to the autonomous-loop instructions at fire time. (There is a similar `<<autonomous-loop>>` sentinel for CronCreate-based autonomous loops; do not confuse the two — ScheduleWakeup always uses the `-dynamic` variant.) To end the loop, call this tool with `stop: true` (omit every other field) — the loop ends immediately and no further wakeups fire.\n\nSet `noop: true` if nothing changed — you checked and there's nothing to report (\"no change\", \"still waiting\", \"quiet hold\"). Set `noop: false` if something happened worth keeping — you edited a file, posted a message, advanced state, or surfaced a finding. Consecutive `noop: true` ticks are collapsed in the user's terminal view and tracked as a streak, so long quiet holds stay legible to the user without scrolling. Omit `noop` when stopping (`stop: true`).\n\n## Picking delaySeconds\n\nThis session's requests use a 1-hour Anthropic prompt-cache TTL, so effectively every allowed delay (the runtime clamps to [60, 3600]) wakes up with your conversation context still cached. There is no cache cliff inside that range to pace around, and scheduling extra wakeups just to keep the cache warm is pure waste — never do that. (If the session enters usage overage, later requests drop to the 5-minute TTL; don't try to track or preempt that — the guidance here stays the same.)\n\nMatch the delay to what you're actually waiting for:\n\n- **Actively polling external state the harness can't notify you about** (a CI run, a deploy, a remote queue): pick the delay from how fast that state actually changes. A CI run that takes ~8 minutes deserves one ~480s check, not eight 60s ones.\n- **The long fallback heartbeat** (something else — a Monitor, a task notification — is the primary wake signal): 1200s+, so quiet wakeups stay rare.\n- **Idle ticks with no specific signal to watch**: default to **1200s–1800s** (20–30 min). The loop still checks back regularly, and the user can always interrupt if they need you sooner.\n\nDon't think in cache windows — think about what you're actually waiting for.\n\n## The reason field\n\nOne short sentence on what you chose and why. Goes to telemetry and is shown back to the user. \"watching CI run\" beats \"waiting.\" The user reads this to understand what you're doing without having to predict your cadence in advance — make it specific.\n",
        "input_schema": {
          "$schema": "https://json-schema.org/draft/2020-12/schema",
          "type": "object",
          "properties": {
            "delaySeconds": {
              "description": "Seconds from now to wake up. Clamped to [60, 3600] by the runtime. Required unless `stop` is true.",
              "type": "number"
            },
            "reason": {
              "description": "One short sentence explaining the chosen delay. Goes to telemetry and is shown to the user. Be specific. Required unless `stop` is true.",
              "type": "string"
            },
            "prompt": {
              "description": "The /loop input to fire on wake-up. Pass the same /loop input verbatim each turn so the next firing re-enters the skill and continues the loop. For autonomous /loop (no user prompt), pass the literal sentinel `<<autonomous-loop-dynamic>>` instead (the dynamic-pacing variant, not the CronCreate-mode `<<autonomous-loop>>`). Required unless `stop` is true.",
              "type": "string"
            },
            "stop": {
              "description": "Set to true to end the dynamic loop immediately instead of scheduling another wakeup. When true, all other fields are ignored and no further wakeups fire.",
              "type": "boolean"
            },
            "noop": {
              "description": "true = nothing changed (you checked and there is nothing to report). false = something happened worth keeping (edited a file, posted a message, advanced state, surfaced a finding). Consecutive noop:true ticks are collapsed in the user's terminal view and tracked as a streak. Required unless `stop` is true.",
              "type": "boolean"
            }
          },
          "additionalProperties": false
        }
      }
    },
    {
      "name": "Skill",
      "description": "Invoke a skill.\n\nA skill is a packaged set of instructions the user or project has set up for a particular kind of task (deploy steps, a review checklist, a repo-specific workflow). Available skills appear in a system-reminder listing with one-line descriptions. When the task at hand is one a listed skill covers, call this tool first — the skill's instructions load into the turn for you to follow in place of your default approach; some skills instead run in a subagent and return the finished result. A skill that runs in the background returns only the agent's name — its result arrives later as a task notification, so don't wait on it or invoke it again in the meantime. Users may also ask for one by name (`/<name>`, or \"slash command\"); that's a request to invoke it.\n\n- `skill`: exact name from the listing, no leading slash. Plugin skills use `plugin:skill`. Directory-scoped skills are listed with a path prefix (`apps/web:deploy`); when both scoped and unscoped variants of a name exist, pick the one whose directory contains the files you're working on (most specific wins; unscoped otherwise).\n- `args`: optional arguments to pass through.\n\nOnly names from the listing (or that the user typed explicitly) are valid. Built-in CLI commands (`/help`, `/clear`, …) aren't skills. If a `<command-name>` block is already present this turn, the skill is loaded — follow it directly rather than calling again.\n",
      "schema": {
        "name": "Skill",
        "description": "Invoke a skill.\n\nA skill is a packaged set of instructions the user or project has set up for a particular kind of task (deploy steps, a review checklist, a repo-specific workflow). Available skills appear in a system-reminder listing with one-line descriptions. When the task at hand is one a listed skill covers, call this tool first — the skill's instructions load into the turn for you to follow in place of your default approach; some skills instead run in a subagent and return the finished result. A skill that runs in the background returns only the agent's name — its result arrives later as a task notification, so don't wait on it or invoke it again in the meantime. Users may also ask for one by name (`/<name>`, or \"slash command\"); that's a request to invoke it.\n\n- `skill`: exact name from the listing, no leading slash. Plugin skills use `plugin:skill`. Directory-scoped skills are listed with a path prefix (`apps/web:deploy`); when both scoped and unscoped variants of a name exist, pick the one whose directory contains the files you're working on (most specific wins; unscoped otherwise).\n- `args`: optional arguments to pass through.\n\nOnly names from the listing (or that the user typed explicitly) are valid. Built-in CLI commands (`/help`, `/clear`, …) aren't skills. If a `<command-name>` block is already present this turn, the skill is loaded — follow it directly rather than calling again.\n",
        "input_schema": {
          "$schema": "https://json-schema.org/draft/2020-12/schema",
          "type": "object",
          "properties": {
            "skill": {
              "description": "The name of a skill from the available-skills list. Do not guess names.",
              "type": "string"
            },
            "args": {
              "description": "Optional arguments for the skill",
              "type": "string"
            }
          },
          "required": [
            "skill"
          ],
          "additionalProperties": false
        }
      }
    },
    {
      "name": "ToolSearch",
      "description": "Fetches full schema definitions for deferred tools so they can be called.\n\nDeferred tools appear by name in <system-reminder> messages. Until fetched, only the name is known — there is no parameter schema, so the tool cannot be invoked. This tool takes a query, matches it against the deferred tool list, and returns the matched tools' complete JSONSchema definitions inside a <functions> block. Once a tool's schema appears in that result, it is callable exactly like any tool defined at the top of the prompt.\n\nResult format: each matched tool appears as one <function>{\"description\": \"...\", \"name\": \"...\", \"parameters\": {...}}</function> line inside the <functions> block — the same encoding as the tool list at the top of this prompt.\n\nQuery forms:\n- \"select:Read,Edit,Grep\" — fetch these exact tools by name\n- \"notebook jupyter\" — keyword search, up to max_results best matches\n- \"+slack send\" — require \"slack\" in the name, rank by remaining terms",
      "schema": {
        "name": "ToolSearch",
        "description": "Fetches full schema definitions for deferred tools so they can be called.\n\nDeferred tools appear by name in <system-reminder> messages. Until fetched, only the name is known — there is no parameter schema, so the tool cannot be invoked. This tool takes a query, matches it against the deferred tool list, and returns the matched tools' complete JSONSchema definitions inside a <functions> block. Once a tool's schema appears in that result, it is callable exactly like any tool defined at the top of the prompt.\n\nResult format: each matched tool appears as one <function>{\"description\": \"...\", \"name\": \"...\", \"parameters\": {...}}</function> line inside the <functions> block — the same encoding as the tool list at the top of this prompt.\n\nQuery forms:\n- \"select:Read,Edit,Grep\" — fetch these exact tools by name\n- \"notebook jupyter\" — keyword search, up to max_results best matches\n- \"+slack send\" — require \"slack\" in the name, rank by remaining terms",
        "input_schema": {
          "$schema": "https://json-schema.org/draft/2020-12/schema",
          "type": "object",
          "properties": {
            "query": {
              "description": "Query to find deferred tools. Use \"select:<tool_name>\" for direct selection, or keywords to search.",
              "type": "string"
            },
            "max_results": {
              "description": "Maximum number of results to return (default: 5)",
              "default": 5,
              "type": "number"
            }
          },
          "required": [
            "query",
            "max_results"
          ],
          "additionalProperties": false
        }
      }
    },
    {
      "name": "Workflow",
      "description": "Execute a workflow script that orchestrates multiple subagents deterministically. Workflows run in the background — this tool returns immediately with a task ID, and a <task-notification> arrives when the workflow completes. Use /workflows to watch live progress.\n\nONLY call this tool when the user has explicitly opted into multi-agent orchestration. Workflows can spawn dozens of agents and consume a large amount of tokens; the user must request that scale, not have it inferred. Explicit opt-in means one of:\n- The user included the keyword \"ultracode\" in their prompt (you'll see a system-reminder confirming it).\n- Ultracode is on for the session (a system-reminder confirms it) — see **Ultracode** in the workflow authoring reference.\n- The user directly asked you to run a workflow or use multi-agent orchestration in their own words (\"use a workflow\", \"run a workflow\", \"fan out agents\", \"orchestrate this with subagents\"). The ask must be in the user's words — a task that would merely benefit from a workflow does not count.\n- The user invoked a skill or slash command whose instructions tell you to call Workflow.\n- The user asked you to run a specific named or saved workflow.\n\nFor any other task — even one that would clearly benefit from parallelism — do NOT call this tool. Use the Agent tool (if available) for individual subagents, or briefly describe what a multi-agent workflow could do and how much it would roughly cost, and ask the user whether to run it. Mention they can ask for one with \"use a workflow\" in a future message to skip the ask.\n\nEvery script must begin with `export const meta = {...}`: a PURE LITERAL (no variables, calls or interpolation) giving the workflow's `name`, a one-line `description` (shown in the permission dialog) and optionally `phases` — one `{ title, detail? }` per phase() call, titles matched exactly. Pass the script inline via `script` — do not Write it to a file first, and do not also set the tool's `name` input (that selects a saved workflow); it is plain JavaScript, not TypeScript.\n\nThe canonical multi-stage pattern — pipeline by default, each dimension verifies as soon as its review completes:\n  export const meta = {\n    name: 'review-changes',\n    description: 'Review changed files across dimensions, verify each finding',\n    phases: [{ title: 'Review' }, { title: 'Verify' }],\n  }\n  const DIMENSIONS = [{key: 'bugs', prompt: '...'}, {key: 'perf', prompt: '...'}]\n  const results = await pipeline(\n    DIMENSIONS,\n    d => agent(d.prompt, {label: `review:${d.key}`, phase: 'Review', schema: FINDINGS_SCHEMA}),\n    review => parallel(review.findings.map(f => () =>\n      agent(`Adversarially verify: ${f.title}`, {label: `verify:${f.file}`, phase: 'Verify', schema: VERDICT_SCHEMA})\n        .then(v => ({...f, verdict: v}))\n    ))\n  )\n  const confirmed = results.flat().filter(Boolean).filter(f => f.verdict?.isReal)\n  return { confirmed }\n  // Dimension 'bugs' findings verify while dimension 'perf' is still reviewing. No wasted wall-clock.\n\nBefore writing a script, load the `workflow-authoring` skill — the workflow authoring reference: script API and gotchas, resume, the **Ultracode** section, quality patterns, worked examples.\n\nThis session has the default workflow size guideline: medium — keep workflows under 10 agents. This is a guideline, not a hard limit — follow it unless the user's prompt calls for a different scale. The user can raise or remove it with \"Dynamic workflow size\" in /config.",
      "schema": {
        "name": "Workflow",
        "description": "Execute a workflow script that orchestrates multiple subagents deterministically. Workflows run in the background — this tool returns immediately with a task ID, and a <task-notification> arrives when the workflow completes. Use /workflows to watch live progress.\n\nONLY call this tool when the user has explicitly opted into multi-agent orchestration. Workflows can spawn dozens of agents and consume a large amount of tokens; the user must request that scale, not have it inferred. Explicit opt-in means one of:\n- The user included the keyword \"ultracode\" in their prompt (you'll see a system-reminder confirming it).\n- Ultracode is on for the session (a system-reminder confirms it) — see **Ultracode** in the workflow authoring reference.\n- The user directly asked you to run a workflow or use multi-agent orchestration in their own words (\"use a workflow\", \"run a workflow\", \"fan out agents\", \"orchestrate this with subagents\"). The ask must be in the user's words — a task that would merely benefit from a workflow does not count.\n- The user invoked a skill or slash command whose instructions tell you to call Workflow.\n- The user asked you to run a specific named or saved workflow.\n\nFor any other task — even one that would clearly benefit from parallelism — do NOT call this tool. Use the Agent tool (if available) for individual subagents, or briefly describe what a multi-agent workflow could do and how much it would roughly cost, and ask the user whether to run it. Mention they can ask for one with \"use a workflow\" in a future message to skip the ask.\n\nEvery script must begin with `export const meta = {...}`: a PURE LITERAL (no variables, calls or interpolation) giving the workflow's `name`, a one-line `description` (shown in the permission dialog) and optionally `phases` — one `{ title, detail? }` per phase() call, titles matched exactly. Pass the script inline via `script` — do not Write it to a file first, and do not also set the tool's `name` input (that selects a saved workflow); it is plain JavaScript, not TypeScript.\n\nThe canonical multi-stage pattern — pipeline by default, each dimension verifies as soon as its review completes:\n  export const meta = {\n    name: 'review-changes',\n    description: 'Review changed files across dimensions, verify each finding',\n    phases: [{ title: 'Review' }, { title: 'Verify' }],\n  }\n  const DIMENSIONS = [{key: 'bugs', prompt: '...'}, {key: 'perf', prompt: '...'}]\n  const results = await pipeline(\n    DIMENSIONS,\n    d => agent(d.prompt, {label: `review:${d.key}`, phase: 'Review', schema: FINDINGS_SCHEMA}),\n    review => parallel(review.findings.map(f => () =>\n      agent(`Adversarially verify: ${f.title}`, {label: `verify:${f.file}`, phase: 'Verify', schema: VERDICT_SCHEMA})\n        .then(v => ({...f, verdict: v}))\n    ))\n  )\n  const confirmed = results.flat().filter(Boolean).filter(f => f.verdict?.isReal)\n  return { confirmed }\n  // Dimension 'bugs' findings verify while dimension 'perf' is still reviewing. No wasted wall-clock.\n\nBefore writing a script, load the `workflow-authoring` skill — the workflow authoring reference: script API and gotchas, resume, the **Ultracode** section, quality patterns, worked examples.\n\nThis session has the default workflow size guideline: medium — keep workflows under 10 agents. This is a guideline, not a hard limit — follow it unless the user's prompt calls for a different scale. The user can raise or remove it with \"Dynamic workflow size\" in /config.",
        "input_schema": {
          "$schema": "https://json-schema.org/draft/2020-12/schema",
          "type": "object",
          "properties": {
            "script": {
              "description": "Self-contained workflow script. Must begin with `export const meta = { name, description, phases }` (pure literal, no computed values) followed by the script body using agent()/parallel()/pipeline()/phase().",
              "type": "string",
              "maxLength": 524288
            },
            "name": {
              "description": "Name of a predefined workflow (built-in or from .claude/workflows/). Resolves to a self-contained script.",
              "type": "string"
            },
            "description": {
              "description": "Ignored — set the workflow description in the script's `meta` block.",
              "type": "string"
            },
            "title": {
              "description": "Ignored — set the workflow title in the script's `meta` block.",
              "type": "string"
            },
            "args": {
              "description": "Optional input value exposed to the script as the global `args`, verbatim. Pass arrays/objects as actual JSON values, NOT as a JSON-encoded string — a stringified list breaks `args.filter`/`args.map` in the script. Use for parameterized named workflows (e.g. a research question)."
            },
            "scriptPath": {
              "description": "Path to a workflow script file on disk. Every Workflow invocation persists its script under the session directory and returns the path in the tool result. To iterate, edit that file with Write/Edit and re-invoke Workflow with the same `scriptPath` instead of re-sending the full script. Takes precedence over `script` and `name`.",
              "type": "string"
            },
            "resumeFromRunId": {
              "description": "Run ID of a prior Workflow invocation to resume from. Completed agent() calls with unchanged (prompt, opts) return their cached results instantly; only edited or new calls re-run. Same-session only. Stop the prior run first (TaskStop) before resuming.",
              "type": "string",
              "pattern": "^wf_[a-z0-9-]{6,}$"
            }
          },
          "additionalProperties": false
        }
      }
    },
    {
      "name": "Write",
      "description": "Writes a file to the local filesystem, overwriting if one exists.\n\nWhen to use: creating a new file, or fully replacing one you've already Read. Overwriting an existing file you haven't Read will fail. For partial changes, use Edit instead.",
      "schema": {
        "name": "Write",
        "description": "Writes a file to the local filesystem, overwriting if one exists.\n\nWhen to use: creating a new file, or fully replacing one you've already Read. Overwriting an existing file you haven't Read will fail. For partial changes, use Edit instead.",
        "input_schema": {
          "$schema": "https://json-schema.org/draft/2020-12/schema",
          "type": "object",
          "properties": {
            "file_path": {
              "description": "The absolute path to the file to write (must be absolute, not relative)",
              "type": "string"
            },
            "content": {
              "description": "The content to write to the file",
              "type": "string"
            }
          },
          "required": [
            "file_path",
            "content"
          ],
          "additionalProperties": false
        }
      }
    }
  ],
  "cliPrefix": "You are a Claude agent, built on Anthropic's Claude Agent SDK.",
  "reminderFold": false,
  "systemTurns": true,
  "toolChangeHeader": true,
  "inlineTools": false,
  "keptReminders": true,
  "echoWireToolInputs": false,
  "contextRendering": "announced"
}
Harness context total tokens reminder
{
  "type": "total_tokens_reminder",
  "text": "<total_tokens>14980719 tokens left</total_tokens>"
}
Harness context batching reminder sent
{
  "type": "batching_reminder_sent",
  "text": "First privately list what you need next; then request every item that doesn't depend on another's result in this one response.",
  "model": "claude-fable-5-1",
  "clearAt": "next_user_message"
}
03

Inspect data schemas and basic statistics

+00:18
Tool callBashInspect data schemas and basic statistics Returned

Tool call · Input

cd /task && python -c "
import pandas as pd, numpy as np
for f in ['candidate_catalog','target_users','validation_preference_state','test_preference_state','train_likes','val_listens']:
    d=pd.read_parquet(f'data/{f}.parquet'); print(f, d.shape); print(d.head(3)); print(d.dtypes.to_dict())
z=np.load('data/validation_eligible_candidates.npz'); print({k:z[k].shape for k in z.files}, z['packed_eligible'].dtype)
m=np.unpackbits(z['packed_eligible'],axis=1,count=len(z['item_ids']),bitorder='little'); print('elig per user', m.sum(1).mean(), m.sum(1).min(), m.sum(1).max())
tl=pd.read_parquet('data/train_listens.parquet'); print(tl.shape, tl.timestamp.min(), tl.timestamp.max(), tl.uid.nunique(), tl.item_id.nunique())
vl=pd.read_parquet('data/val_listens.parquet'); print(vl.shape, vl.timestamp.min(), vl.timestamp.max())
tu=set(pd.read_parquet('data/target_users.parquet').uid)
print('target in train listens', tl.uid.isin(tu).mean())
cat=set(pd.read_parquet('data/candidate_catalog.parquet').item_id)
vo=vl[(vl.uid.isin(tu))&(vl.is_organic==1)&(vl.played_ratio_pct>=80)&(vl.item_id.isin(cat))]
print('val strong organic listens on catalog', len(vo), vo.uid.nunique())
# how many val positives were previously heard in train by same user?
pairs=set(zip(tl.uid,tl.item_id))
print('frac val strong pairs seen in train', np.mean([(u,i) in pairs for u,i in zip(vo.uid,vo.item_id)]))
"

Tool response

candidate_catalog (30000, 4)
   item_id  positive_listens  organic_positive_listens  popularity_rank
0  5862961             26615                     20620                1
1  6901374             25536                     17347                2
2  5635052             24691                     17194                3
{'item_id': dtype('uint32'), 'positive_listens': dtype('int64'), 'organic_positive_listens': dtype('uint64'), 'popularity_rank': dtype('int32')}
target_users (8456, 3)
   uid  recent_positive_listens  history_positive_listens
0  100                    844.0                      2604
1  200                     50.0                       286
2  300                    168.0                       359
{'uid': dtype('uint32'), 'recent_positive_listens': dtype('float64'), 'history_positive_listens': dtype('int64')}
validation_preference_state (469124, 3)
   uid  item_id  state
0  100   410868  liked
1  100   732449  liked
2  100   982903  liked
{'uid': dtype('uint32'), 'item_id': dtype('uint32'), 'state': dtype('O')}
test_preference_state (484776, 3)
   uid  item_id  state
0  100   410868  liked
1  100   732449  liked
2  100   982903  liked
{'uid': dtype('uint32'), 'item_id': dtype('uint32'), 'state': dtype('O')}
train_likes (814831, 4)
   uid  timestamp  item_id  is_organic
0  100      44755   732449           1
1  100    1155860  6568592           0
2  100    1259125  5411243           1
{'uid': dtype('uint32'), 'timestamp': dtype('uint32'), 'item_id': dtype('uint32'), 'is_organic': dtype('uint8')}
val_listens (1501697, 6)
   uid  timestamp  item_id  is_organic  played_ratio_pct  track_length_seconds
0  100   24943430  9321269           0               100                   195
1  100   24943605  5452713           0               100                   175
2  100   24943765  6448777           0               100                   160
{'uid': dtype('uint32'), 'timestamp': dtype('uint32'), 'item_id': dtype('uint32'), 'is_organic': dtype('uint8'), 'played_ratio_pct': dtype('uint16'), 'track_length_seconds': dtype('uint32')}
{'uids': (8456,), 'item_ids': (30000,), 'packed_eligible': (8456, 3750)} uint8
elig per user 29067.306291390727 24657 30000
(43484159, 6) 0 24786795 9238 845395
(1501697, 6) 24788600 25393395
target in train listens 0.9939779909276847
val strong organic listens on catalog 288828 6027
frac val strong pairs seen in train 0.8128713282645726
Shell cwd was reset to /app
Harness context total tokens reminder
{
  "type": "total_tokens_reminder",
  "text": "<total_tokens>14976302 tokens left</total_tokens>"
}
Harness context batching reminder sent
{
  "type": "batching_reminder_sent",
  "text": "First privately list what you need next; then request every item that doesn't depend on another's result in this one response.",
  "model": "claude-fable-5-1",
  "clearAt": "next_user_message"
}
04

Check eligibility rules vs history and repeat-consumption rate

+00:54
Recorded reasoning 138 words

81% of validation strong pairs were already seen by the same user in train, and eligibility apparently includes nearly all previously listened items (~29k of 30k eligible), so I should check what's actually excluded—likely liked/disliked items. This tells me repeat-consumption features based on a user's own history with an item could be extremely predictive, so with limited time left I'm planning to build a per-user scoring approach leveraging candidate history against eligibility.

Given the time crunch, I'll start with a strong heuristic combining recency-weighted past listens, played ratio, item popularity, and item-item co-occurrence for discovery, and save that as a baseline submission before attempting a quick gradient boosted model if time allows. First I want to confirm what's excluded from eligibility and double check the fraction of validation positives that were already heard in train among eligible items.

Tool callBashCheck eligibility rules vs history and repeat-consumption rate Returned

Tool call · Input

cd /task && python -c "
import pandas as pd, numpy as np
z=np.load('data/validation_eligible_candidates.npz'); items=z['item_ids']; uids=z['uids']
m=np.unpackbits(z['packed_eligible'],axis=1,count=len(items),bitorder='little').astype(bool)
ipos={i:k for k,i in enumerate(items)}; upos={u:k for k,u in enumerate(uids)}
ps=pd.read_parquet('data/validation_preference_state.parquet')
ps=ps[ps.item_id.isin(ipos)]
for st in ['liked','disliked']:
    s=ps[ps.state==st]; r=np.array([upos[u] for u in s.uid]); c=np.array([ipos[i] for i in s.item_id])
    print(st, len(s), 'eligible frac', m[r,c].mean())
tl=pd.read_parquet('data/train_listens.parquet', columns=['uid','item_id','is_organic','played_ratio_pct','timestamp'])
tl=tl[tl.uid.isin(upos)&tl.item_id.isin(ipos)]
p=tl.drop_duplicates(['uid','item_id'])
r=np.array([upos[u] for u in p.uid]); c=np.array([ipos[i] for i in p.item_id])
print('train listened pairs', len(p), 'eligible frac', m[r,c].mean())
inel=~m[r,c]
print('ineligible-but-listened count', inel.sum())
# Among val relevant pairs (eligible), fraction heard in train
vl=pd.read_parquet('data/val_listens.parquet'); vk=pd.read_parquet('data/val_likes.parquet')
rel=pd.concat([vl[(vl.is_organic==1)&(vl.played_ratio_pct>=80)][['uid','item_id']], vk[vk.is_organic==1][['uid','item_id']]]).drop_duplicates()
rel=rel[rel.uid.isin(upos)&rel.item_id.isin(ipos)]
rr=np.array([upos[u] for u in rel.uid]); rc=np.array([ipos[i] for i in rel.item_id]); rel=rel[m[rr,rc]]
seen=set(zip(p.uid,p.item_id))
rel['seen']=[(u,i) in seen for u,i in zip(rel.uid,rel.item_id)]
print('eligible relevant pairs', len(rel), 'seen frac', rel.seen.mean(), 'users', rel.uid.nunique())
print(rel.groupby('uid').size().describe())
# recency of last listen in train
print('train ts range', tl.timestamp.min(), tl.timestamp.max())
"

Tool response

liked 418435 eligible frac 0.0
disliked 50689 eligible frac 0.0
train listened pairs 7868664 eligible frac 0.0
ineligible-but-listened count 7868664
eligible relevant pairs 37769 seen frac 0.0 users 4263
count    4263.000000
mean        8.859723
std        15.773444
min         1.000000
25%         2.000000
50%         4.000000
75%        10.000000
max       442.000000
dtype: float64
train ts range 5 24786795
Shell cwd was reset to /app
Harness context total tokens reminder
{
  "type": "total_tokens_reminder",
  "text": "<total_tokens>14973946 tokens left</total_tokens>"
}
Harness context batching reminder sent
{
  "type": "batching_reminder_sent",
  "text": "First privately list what you need next; then request every item that doesn't depend on another's result in this one response.",
  "model": "claude-fable-5-1",
  "clearAt": "next_user_message"
}
05

Write CF ranker script and run validation stage

+01:56
Recorded reasoning 350 words

This clarifies that eligible candidates exclude all previously listened items, making this a true cold discovery task with roughly 29k eligible items per user out of 30k, and about 4263 scored users averaging 8.9 relevant items each — pointing toward pure collaborative filtering via item-item similarity.

Given the 30-minute budget, I'm weighing options: item-based CF with cosine similarity plus a popularity prior, a quick truncated SVD on the sparse user-item matrix, or EASE with a closed-form solution. EASE would need a 30k×30k Gram matrix (3.6GB in float32) and a cubic-time inversion that could take several minutes on 8 cores — risky but maybe just feasible, while item-KNN scoring via sparse-times-dense multiplication looks more comfortably within memory and time limits.

The float64 precision needed for stable matrix inversion would push memory requirements too high for EASE, so I'm leaning toward item-KNN with time-decay weighting on user history as the safer, more robust choice, tuning a couple hyperparameters on validation before refitting. I also need to think about scope — restricting similarity computations to the 30k catalog items rather than the full 845k item universe, and considering whether user-user CF (over just 9238 users) could be a cheap complementary signal alongside item-item similarity.

For weighting, I'll treat listens with a played ratio of 50% or higher as positive signals with extra weight for organic plays, give likes a weight of 3, and penalize dislikes, folding validation events into the final refit. I'm now planning the actual scoring approach: building a user-by-catalog-item weighted interaction matrix for training, computing shrinkage-adjusted cosine similarity between items for item-based scoring, and also constructing a full user-by-all-items matrix to support user-user similarity as a second signal to blend in.

Since timestamps look like they span roughly 287 days, I should apply a recency decay (something like a 30-day half-life) so recent interactions matter more, matching the fact that the hidden test window comes later in time. I'll also fold in a popularity prior from recent organic positives and combine all these scores using rank-normalized or z-scored blending, tuning the weights against validation data before writing the actual pipeline.

Recorded reasoning 41 words

Since eligible candidates exclude anything the user has already listened to, liked, or disliked, this is a pure discovery task via collaborative filtering. I'll build item-item and user-user neighborhood scorers plus a popularity prior, blend them, and tune using validation data.

Tool callBashWrite CF ranker script and run validation stage Error

Tool call · Input

mkdir -p /app/solution && cat > /app/solution/build.py <<'EOF'
"""Discovery ranker for the "Made for You" shelf.

Approach: neighbourhood collaborative filtering on a weighted, time-decayed
user x item interaction matrix (listens >=50%, likes, dislikes), with
  * item-item cosine scores (catalog items),
  * user-user cosine scores (computed over the full item space),
  * a recent-organic popularity prior,
blended with rank-tuned weights. Stage "val" fits on train_* and is scored by
/task/evaluate_public.py; stage "test" refits on train_* + val_* and writes the
final submission.
"""
import sys, time, json
import numpy as np, pandas as pd, scipy.sparse as sp

D = '/task/data/'
OUT = '/app/solution/'
STAGE = sys.argv[1] if len(sys.argv) > 1 else 'val'
PARAMS = json.loads(sys.argv[2]) if len(sys.argv) > 2 else {}
HL_DAYS = PARAMS.get('hl', 60.0)          # half-life for interaction decay
W_II, W_UU, W_POP = PARAMS.get('w_ii', 1.0), PARAMS.get('w_uu', 0.5), PARAMS.get('w_pop', 0.1)
SHRINK = PARAMS.get('shrink', 10.0)
POP_DAYS = PARAMS.get('pop_days', 30.0)
NEIGH = PARAMS.get('kuu', 200)
t0 = time.time()

def load(fam):
    fs = ['train_'] + (['val_'] if STAGE == 'test' else [])
    return pd.concat([pd.read_parquet(f'{D}{f}{fam}.parquet') for f in fs], ignore_index=True)

elig = np.load(D + ('test' if STAGE == 'test' else 'validation') + '_eligible_candidates.npz')
uids, items = elig['uids'], elig['item_ids']
mask = np.unpackbits(elig['packed_eligible'], axis=1, count=len(items), bitorder='little').astype(bool)
upos = pd.Series(np.arange(len(uids)), index=uids)
ipos = pd.Series(np.arange(len(items)), index=items)

listens = load('listens'); likes = load('likes'); dislikes = load('dislikes')
cutoff = listens.timestamp.max()
print('loaded', time.time() - t0, 'cutoff', cutoff)

def decay(ts):
    return np.power(0.5, (cutoff - ts.astype(np.float64)) / (HL_DAYS * 86400))

# weighted interactions
pos = listens[listens.played_ratio_pct >= 50]
ev = pd.concat([
    pd.DataFrame({'uid': pos.uid, 'item_id': pos.item_id,
                  'w': (1.0 + 0.5 * pos.is_organic) * decay(pos.timestamp)}),
    pd.DataFrame({'uid': likes.uid, 'item_id': likes.item_id, 'w': 3.0 * decay(likes.timestamp)}),
    pd.DataFrame({'uid': dislikes.uid, 'item_id': dislikes.item_id, 'w': -2.0 * decay(dislikes.timestamp)}),
], ignore_index=True)
agg = ev.groupby(['uid', 'item_id'], sort=False).w.sum().reset_index()
agg['w'] = np.log1p(np.clip(agg.w, 0, None)) - np.log1p(np.clip(-agg.w, 0, None))
# all users (not just targets) contribute to item similarities
all_users = pd.Index(agg.uid.unique())
u_all = all_users.get_indexer(agg.uid)
all_items = pd.Index(agg.item_id.unique())
i_all = all_items.get_indexer(agg.item_id)
Xfull = sp.csr_matrix((agg.w.values.astype(np.float32), (u_all, i_all)), shape=(len(all_users), len(all_items)))
incat = all_items.isin(items)
Xcat = Xfull[:, np.where(incat)[0]]
cat_cols = ipos.reindex(all_items[incat]).values  # map Xcat columns -> catalog positions
print('matrix', Xfull.shape, Xfull.nnz, time.time() - t0)

# ---- item-item cosine (catalog items) ----
Xp = Xcat.copy(); Xp.data = np.clip(Xp.data, 0, None); Xp.eliminate_zeros()
G = (Xp.T @ Xp).toarray().astype(np.float32)
nrm = np.sqrt(np.diag(G)) + 1e-6
S = G / (nrm[:, None] * nrm[None, :] + SHRINK)
np.fill_diagonal(S, 0)
del G
trow = all_users.get_indexer(uids)  # target users rows in Xfull (-1 if none)
Xt = Xcat[np.clip(trow, 0, None)]
Xt[trow < 0] = 0
score_ii = np.zeros((len(uids), len(items)), np.float32)
score_ii[:, cat_cols] = np.asarray(Xt @ S)
del S
print('item-item done', time.time() - t0)

# ---- user-user cosine over full item space ----
Xb = Xfull.copy(); Xb.data = np.clip(Xb.data, 0, None); Xb.eliminate_zeros()
un = np.sqrt(np.asarray(Xb.multiply(Xb).sum(1)).ravel()) + 1e-6
Xn = sp.diags(1 / un) @ Xb
Suu = np.asarray((Xn[np.clip(trow, 0, None)] @ Xn.T).todense()).astype(np.float32)
Suu[trow < 0] = 0
Suu[np.arange(len(uids)), np.clip(trow, 0, None)] = 0  # remove self
if NEIGH and NEIGH < Suu.shape[1]:
    thr = -np.partition(-Suu, NEIGH, axis=1)[:, NEIGH][:, None]
    Suu[Suu < thr] = 0
score_uu = np.zeros((len(uids), len(items)), np.float32)
Xbc = Xb[:, np.where(incat)[0]]
score_uu[:, cat_cols] = np.asarray(sp.csr_matrix(Suu) @ Xbc).astype(np.float32) if False else (sp.csr_matrix(Suu) @ Xbc).toarray()
print('user-user done', time.time() - t0)

# ---- popularity prior (recent organic strong listens + organic likes) ----
rec = listens[(listens.timestamp > cutoff - POP_DAYS * 86400) & (listens.is_organic == 1) & (listens.played_ratio_pct >= 80)]
pc = rec.item_id.value_counts()
lk = likes[(likes.timestamp > cutoff - POP_DAYS * 86400) & (likes.is_organic == 1)].item_id.value_counts()
pop = np.log1p(pc.reindex(items).fillna(0).values + 3 * lk.reindex(items).fillna(0).values).astype(np.float32)

def znorm(a):
    m = a.mean(1, keepdims=True); s = a.std(1, keepdims=True) + 1e-6
    return (a - m) / s

final = W_II * znorm(score_ii) + W_UU * znorm(score_uu) + W_POP * (pop - pop.mean()) / pop.std()
final[~mask] = -np.inf
top = np.argpartition(-final, 100, axis=1)[:, :100]
ts = np.take_along_axis(final, top, 1)
order = np.argsort(-ts, axis=1)
top = np.take_along_axis(top, order, 1)
sub = pd.DataFrame({'uid': np.repeat(uids, 100).astype(np.int64),
                    'item_id': items[top.ravel()].astype(np.int64),
                    'rank': np.tile(np.arange(1, 101), len(uids)).astype(np.int64)})
name = 'submission.parquet' if STAGE == 'test' else PARAMS.get('out', 'validation.parquet')
sub.to_parquet(OUT + name, index=False)
print('wrote', OUT + name, time.time() - t0)
EOF
cd /app/solution && python build.py val && python /task/evaluate_public.py /app/solution/validation.parquet

Options

{
  "timeout": 600000
}

Tool response · Tool error

Exit code 137
/bin/bash: line 235:  8169 Killed                  python build.py val
Harness context total tokens reminder
{
  "type": "total_tokens_reminder",
  "text": "<total_tokens>14969279 tokens left</total_tokens>"
}
Harness context batching reminder sent
{
  "type": "batching_reminder_sent",
  "text": "First privately list what you need next; then request every item that doesn't depend on another's result in this one response.",
  "model": "claude-fable-5-1",
  "clearAt": "next_user_message"
}
06

Patch memory usage and rerun validation

+03:04
Recorded reasoning 52 words

I'm hitting an out-of-memory issue, likely from the full listens data plus the large dense matrices consuming too much RAM at once. I need to trim this down by loading only the necessary columns, freeing the listens data early, and computing the normalization in float32 in-place rather than creating extra temporary arrays.

Model text

Out of memory. The dense 30k×30k item similarity plus temporaries exceeded RAM. I'll load only needed columns, free the raw listens early, and normalize the similarity matrix in place by blocks.

Tool callBashPatch memory usage and rerun validation Error

Tool call · Input

cd /app/solution && python - <<'EOF'
import re
s = open('build.py').read()
s = s.replace("""def load(fam):
    fs = ['train_'] + (['val_'] if STAGE == 'test' else [])
    return pd.concat([pd.read_parquet(f'{D}{f}{fam}.parquet') for f in fs], ignore_index=True)""",
"""def load(fam, cols=None):
    fs = ['train_'] + (['val_'] if STAGE == 'test' else [])
    return pd.concat([pd.read_parquet(f'{D}{f}{fam}.parquet', columns=cols) for f in fs], ignore_index=True)""")
s = s.replace("listens = load('listens'); likes = load('likes'); dislikes = load('dislikes')",
"listens = load('listens', ['uid','timestamp','item_id','is_organic','played_ratio_pct']); likes = load('likes'); dislikes = load('dislikes')")
# popularity computed before deleting listens: move the popularity block up, right after events
pop_block = s[s.index("# ---- popularity prior"):s.index("def znorm")]
s = s.replace(pop_block, "")
s = s.replace("agg = ev.groupby(", pop_block + "del pos\nagg = ev.groupby(")
s = s.replace("agg['w'] = np.log1p(np.clip(agg.w, 0, None)) - np.log1p(np.clip(-agg.w, 0, None))",
"agg['w'] = np.log1p(np.clip(agg.w, 0, None)) - np.log1p(np.clip(-agg.w, 0, None))\ndel listens, ev, rec\nimport gc; gc.collect()")
s = s.replace("""G = (Xp.T @ Xp).toarray().astype(np.float32)
nrm = np.sqrt(np.diag(G)) + 1e-6
S = G / (nrm[:, None] * nrm[None, :] + SHRINK)
np.fill_diagonal(S, 0)
del G""",
"""S = (Xp.T @ Xp).toarray().astype(np.float32)
nrm = (np.sqrt(np.diag(S)) + 1e-6).astype(np.float32)
for a in range(0, S.shape[0], 2000):
    blk = S[a:a+2000]
    blk /= (nrm[a:a+2000, None] * nrm[None, :] + np.float32(SHRINK))
np.fill_diagonal(S, 0)""")
open('build.py','w').write(s)
EOF
grep -n "popularity" -A6 build.py | head -20; python build.py val && python /task/evaluate_public.py /app/solution/validation.parquet

Options

{
  "timeout": 600000
}

Tool response · Tool error

Exit code 137
7:  * a recent-organic popularity prior,
8-blended with rank-tuned weights. Stage "val" fits on train_* and is scored by
9-/task/evaluate_public.py; stage "test" refits on train_* + val_* and writes the
10-final submission.
11-"""
12-import sys, time, json
13-import numpy as np, pandas as pd, scipy.sparse as sp
--
51:# ---- popularity prior (recent organic strong listens + organic likes) ----
52-rec = listens[(listens.timestamp > cutoff - POP_DAYS * 86400) & (listens.is_organic == 1) & (listens.played_ratio_pct >= 80)]
53-pc = rec.item_id.value_counts()
54-lk = likes[(likes.timestamp > cutoff - POP_DAYS * 86400) & (likes.is_organic == 1)].item_id.value_counts()
55-pop = np.log1p(pc.reindex(items).fillna(0).values + 3 * lk.reindex(items).fillna(0).values).astype(np.float32)
56-
57-del pos
/bin/bash: line 61:  8205 Killed                  python build.py val
Harness context total tokens reminder
{
  "type": "total_tokens_reminder",
  "text": "<total_tokens>14967934 tokens left</total_tokens>"
}
Harness context batching reminder sent
{
  "type": "batching_reminder_sent",
  "text": "First privately list what you need next; then request every item that doesn't depend on another's result in this one response.",
  "model": "claude-fable-5-1",
  "clearAt": "next_user_message"
}
07

Check memory limit, use dense Gram product, rerun

+03:59
Recorded reasoning 107 words

It's still getting killed somewhere and I need to pinpoint where. I'm estimating memory usage at each stage—the listens loading, the concatenated DataFrame, the pos filter—and none of those seem large enough to cause it, so I suspect the sparse matrix product Xp.T @ Xp might be the culprit.

Actually, converting to dense and doing the matmul directly should be more memory-efficient than letting the sparse product blow up with excessive nonzeros. I also want to check whether the container has a lower cgroup memory limit than the reported 14GB, and I should add memory print statements at each stage to pin down exactly where things fail.

Tool callBashCheck memory limit, use dense Gram product, rerun Error

Tool call · Input

cat /sys/fs/cgroup/memory.max 2>/dev/null; cat /sys/fs/cgroup/memory/memory.limit_in_bytes 2>/dev/null; cd /app/solution && python - <<'EOF'
s = open('build.py').read()
s = s.replace("S = (Xp.T @ Xp).toarray().astype(np.float32)",
"""Xd = Xp.toarray().astype(np.float32); del Xp
S = Xd.T @ Xd; del Xd
import resource; print('maxrss GB', resource.getrusage(resource.RUSAGE_SELF).ru_maxrss/1e6)""")
s = s.replace("print('matrix', Xfull.shape, Xfull.nnz, time.time() - t0)",
"import resource; print('matrix', Xfull.shape, Xfull.nnz, time.time() - t0, 'maxrss GB', resource.getrusage(resource.RUSAGE_SELF).ru_maxrss/1e6)")
open('build.py','w').write(s)
EOF
python build.py val 2>&1 | tail -20 && python /task/evaluate_public.py /app/solution/validation.parquet

Options

{
  "timeout": 600000
}

Tool response · Tool error

Exit code 1
8589934592
Traceback (most recent call last):
  File "/task/evaluate_public.py", line 157, in <module>
    main()
  File "/task/evaluate_public.py", line 152, in main
    ranked = load_submission(path, eligibility, targets)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/task/evaluate_public.py", line 113, in load_submission
    frame = validate_ranking(read_ranking(path), targets)
                             ^^^^^^^^^^^^^^^^^^
  File "/task/ranking_evaluation.py", line 98, in read_ranking
    return pd.read_parquet(path) if path.suffix == ".parquet" else pd.read_csv(path)
           ^^^^^^^^^^^^^^^^^^^^^
  File "/opt/task-venv/lib/python3.12/site-packages/pandas/io/parquet.py", line 669, in read_parquet
    return impl.read(
           ^^^^^^^^^^
  File "/opt/task-venv/lib/python3.12/site-packages/pandas/io/parquet.py", line 258, in read
    path_or_handle, handles, filesystem = _get_path_or_handle(
                                          ^^^^^^^^^^^^^^^^^^^^
  File "/opt/task-venv/lib/python3.12/site-packages/pandas/io/parquet.py", line 141, in _get_path_or_handle
    handles = get_handle(
              ^^^^^^^^^^^
  File "/opt/task-venv/lib/python3.12/site-packages/pandas/io/common.py", line 882, in get_handle
    handle = open(handle, ioargs.mode)
             ^^^^^^^^^^^^^^^^^^^^^^^^^
FileNotFoundError: [Errno 2] No such file or directory: '/app/solution/validation.parquet'
Harness context total tokens reminder
{
  "type": "total_tokens_reminder",
  "text": "<total_tokens>14966515 tokens left</total_tokens>"
}
Harness context batching reminder sent
{
  "type": "batching_reminder_sent",
  "text": "First privately list what you need next; then request every item that doesn't depend on another's result in this one response.",
  "model": "claude-fable-5-1",
  "clearAt": "next_user_message"
}
08

Replace item-item block with factored form and rerun

+06:03
Recorded reasoning 175 words

The missing "loaded" output was likely just Python's stdout buffering when piped through tail, so I should rerun with python -u to force unbuffered output. With an 8GB memory limit, I need to account for the 30k×30k float32 similarity matrix at 3.6GB plus the score_ii array, which could be pushing close to the ceiling.

I'm weighing memory-saving strategies: computing S in blocks and writing directly into score_ii before deleting S, freeing listens/agg data before the peak allocation, or avoiding materializing the full item-item matrix entirely by factoring the computation through the smaller catalog-restricted dot product. I'm working through whether the shrinkage term in the normalized similarity breaks this factorization trick, and whether the diagonal removal simplifies nicely when there's no shrink.

I realize I can skip computing the full similarity matrix altogether — the item-item cosine score reduces to a product of scaled Xt and Xp matrices through a diagonal normalization, which keeps memory trivial and leaves room for asymmetric cosine variants. I'll rewrite this part accordingly, run with unbuffered output, and save progress early.

Recorded reasoning 35 words

The 8 GB container limit rules out building the dense 30k×30k similarity matrix. Instead, I'll compute the item-item cosine scores via factored matrix operations (X·D·Xᵀ)·(X·D) to avoid ever materializing it, and run with unbuffered output.

Tool callBashReplace item-item block with factored form and rerun Error

Tool call · Input

cd /app/solution && python - <<'EOF'
s = open('build.py').read()
a = s.index("# ---- item-item cosine"); b = s.index("# ---- user-user cosine")
new = """# ---- item-item cosine (catalog items), factored to avoid a dense 30k x 30k matrix ----
# S = D G D with G = Xp^T Xp, D = diag(1/||x_i||^ALPHA);  score = (Xt D) Xp^T (Xp D)
ALPHA = PARAMS.get('alpha', 1.0)
Xp = Xcat.copy(); Xp.data = np.clip(Xp.data, 0, None); Xp.eliminate_zeros()
inorm = np.sqrt(np.asarray(Xp.multiply(Xp).sum(0)).ravel()) + 1e-6
Dn = sp.diags((1 / inorm ** ALPHA).astype(np.float32))
XpD = (Xp @ Dn).tocsr()
trow = all_users.get_indexer(uids)  # target users rows in Xfull (-1 if none)
Xt = Xcat[np.clip(trow, 0, None)].tolil(); Xt[trow < 0] = 0; Xt = Xt.tocsr()
A = (Xt @ Dn @ Xp.T).toarray().astype(np.float32)          # users x all-users
score_ii = np.zeros((len(uids), len(items)), np.float32)
score_ii[:, cat_cols] = (sp.csr_matrix(A) @ XpD).toarray()
del A
print('item-item done', time.time() - t0)

"""
s = s[:a] + new + s[b:]
open('build.py','w').write(s)
EOF
python -u build.py val 2>&1 | tail -20 && python /task/evaluate_public.py /app/solution/validation.parquet

Options

{
  "timeout": 600000
}

Tool response · Tool error

Exit code 1
loaded 0.7350249290466309 cutoff 24786795
matrix (9970, 624519) 8730454 5.429641485214233 maxrss GB 3.961192
item-item done 94.08055424690247
user-user done 111.15766072273254
Traceback (most recent call last):
  File "/task/evaluate_public.py", line 157, in <module>
    main()
  File "/task/evaluate_public.py", line 152, in main
    ranked = load_submission(path, eligibility, targets)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/task/evaluate_public.py", line 113, in load_submission
    frame = validate_ranking(read_ranking(path), targets)
                             ^^^^^^^^^^^^^^^^^^
  File "/task/ranking_evaluation.py", line 98, in read_ranking
    return pd.read_parquet(path) if path.suffix == ".parquet" else pd.read_csv(path)
           ^^^^^^^^^^^^^^^^^^^^^
  File "/opt/task-venv/lib/python3.12/site-packages/pandas/io/parquet.py", line 669, in read_parquet
    return impl.read(
           ^^^^^^^^^^
  File "/opt/task-venv/lib/python3.12/site-packages/pandas/io/parquet.py", line 258, in read
    path_or_handle, handles, filesystem = _get_path_or_handle(
                                          ^^^^^^^^^^^^^^^^^^^^
  File "/opt/task-venv/lib/python3.12/site-packages/pandas/io/parquet.py", line 141, in _get_path_or_handle
    handles = get_handle(
              ^^^^^^^^^^^
  File "/opt/task-venv/lib/python3.12/site-packages/pandas/io/common.py", line 882, in get_handle
    handle = open(handle, ioargs.mode)
             ^^^^^^^^^^^^^^^^^^^^^^^^^
FileNotFoundError: [Errno 2] No such file or directory: '/app/solution/validation.parquet'
Harness context total tokens reminder
{
  "type": "total_tokens_reminder",
  "text": "<total_tokens>14964219 tokens left</total_tokens>"
}
Harness context batching reminder sent
{
  "type": "batching_reminder_sent",
  "text": "First privately list what you need next; then request every item that doesn't depend on another's result in this one response.",
  "model": "claude-fable-5-1",
  "clearAt": "next_user_message"
}
09

Cache components, add blend script, run validation

+08:16
Recorded reasoning 113 words

It got killed after the user-user blending step finished — znorm generates multiple temporary copies plus the final matrix, which pushes memory past 8GB given the ~4GB baseline. Item-item also took 90s due to the slow sparse matrix multiplication. I need to fix the memory issue by doing znorm in place, computing the final result in place, and deleting intermediates as soon as possible.

I should also save the score components (score_ii, score_uu, pop) to disk using np.save in a cache directory so I can tune blend weights later without recomputing everything — this matters given the time budget already spent. I'll set up a separate blend script that loads these cached scores.

Model text

Killed again at the blend stage from temporaries. I'll make the blend in-place, and cache the score components to disk so I can tune blend weights without recomputing.

Tool callBashCache components, add blend script, run validation Returned

Tool call · Input

cd /app/solution && python - <<'EOF'
s = open('build.py').read()
a = s.index("def znorm")
s = s[:a] + """import os
cd = OUT + f'cache_{STAGE}/'; os.makedirs(cd, exist_ok=True)
np.save(cd + 'ii.npy', score_ii); np.save(cd + 'uu.npy', score_uu); np.save(cd + 'pop.npy', pop)
print('cached components', time.time() - t0)
"""
open('build.py','w').write(s)
EOF
cat > blend.py <<'EOF'
"""Blend cached score components and write a ranking. Usage: blend.py STAGE '{json params}'"""
import sys, json, numpy as np, pandas as pd, gc
STAGE = sys.argv[1]; P = json.loads(sys.argv[2]) if len(sys.argv) > 2 else {}
D = '/task/data/'; OUT = '/app/solution/'; cd = OUT + f'cache_{STAGE}/'
elig = np.load(D + ('test' if STAGE == 'test' else 'validation') + '_eligible_candidates.npz')
uids, items = elig['uids'], elig['item_ids']
mask = np.unpackbits(elig['packed_eligible'], axis=1, count=len(items), bitorder='little').astype(bool)
def znorm_(a):
    a -= a.mean(1, keepdims=True); a /= (a.std(1, keepdims=True) + 1e-6); return a
final = np.load(cd + 'ii.npy'); znorm_(final); final *= np.float32(P.get('w_ii', 1.0))
uu = np.load(cd + 'uu.npy'); znorm_(uu); uu *= np.float32(P.get('w_uu', 0.5)); final += uu; del uu; gc.collect()
pop = np.load(cd + 'pop.npy'); pop = (pop - pop.mean()) / pop.std()
final += np.float32(P.get('w_pop', 0.1)) * pop[None, :]
final[~mask] = -np.inf
top = np.argpartition(-final, 100, axis=1)[:, :100]
ts = np.take_along_axis(final, top, 1)
top = np.take_along_axis(top, np.argsort(-ts, axis=1), 1)
sub = pd.DataFrame({'uid': np.repeat(uids, 100).astype(np.int64), 'item_id': items[top.ravel()].astype(np.int64),
                    'rank': np.tile(np.arange(1, 101), len(uids)).astype(np.int64)})
name = P.get('out', 'submission.parquet' if STAGE == 'test' else 'validation.parquet')
sub.to_parquet(OUT + name, index=False); print('wrote', name)
EOF
python -u build.py val 2>&1 | tail -3 && python blend.py val '{}' && python /task/evaluate_public.py /app/solution/validation.parquet

Options

{
  "timeout": 600000
}

Tool response

item-item done 94.22801923751831
user-user done 111.30362582206726
cached components 121.94005513191223
wrote validation.parquet
{
  "model": "/app/solution/validation.parquet",
  "scores": {
    "quality_ndcg@10": 0.02219,
    "quality_users": 4263
  }
}
Harness context environment
{
  "type": "environment",
  "snapshot": {
    "workingDirectory": "/app/solution",
    "isWorktree": false,
    "isGitRepo": false,
    "additionalWorkingDirectories": [],
    "platform": "linux",
    "shell": "unknown",
    "osVersion": "Linux 7.0.0-1013-aws"
  },
  "changes": [
    {
      "field": "workingDirectory",
      "from": "/app"
    }
  ]
}
Harness context total tokens reminder
{
  "type": "total_tokens_reminder",
  "text": "<total_tokens>14961968 tokens left</total_tokens>"
}
Harness context batching reminder sent
{
  "type": "batching_reminder_sent",
  "text": "First privately list what you need next; then request every item that doesn't depend on another's result in this one response.",
  "model": "claude-fable-5-1",
  "clearAt": "next_user_message"
}
10

Start test-stage refit in background

+10:43
Recorded reasoning 42 words

Score is 0.0222 with about 15 minutes used. I should kick off the test-stage build in the background now to guarantee a valid submission while I tune blend weights on validation in parallel, then apply the best weights to the test blend.

Model text

Pipeline works with NDCG@10 of 0.0222 on validation. Now I'll start the test-stage refit in the background to guarantee a valid submission, and in parallel sweep blend weights on validation.

Tool callBashStart test-stage refit in background Returned

Tool call · Input

nohup python -u build.py test > build_test.log 2>&1 &
sleep 1; echo started

Tool response

started
Harness context total tokens reminder
{
  "type": "total_tokens_reminder",
  "text": "<total_tokens>14961529 tokens left</total_tokens>"
}
Harness context batching reminder sent
{
  "type": "batching_reminder_sent",
  "text": "First privately list what you need next; then request every item that doesn't depend on another's result in this one response.",
  "model": "claude-fable-5-1",
  "clearAt": "next_user_message"
}
11

Sweep blend weights on validation

+10:50
Tool callBashSweep blend weights on validation Returned

Tool call · Input

for p in '{"w_ii":1,"w_uu":0,"w_pop":0}' '{"w_ii":0,"w_uu":1,"w_pop":0}' '{"w_ii":0,"w_uu":0,"w_pop":1}' '{"w_ii":1,"w_uu":1,"w_pop":0.1}' '{"w_ii":1,"w_uu":0.5,"w_pop":0.3}'; do echo "$p"; python blend.py val "$p" >/dev/null && python /task/evaluate_public.py validation.parquet | grep ndcg; done

Options

{
  "timeout": 600000
}

Tool response

{"w_ii":1,"w_uu":0,"w_pop":0}
    "quality_ndcg@10": 0.017269,
{"w_ii":0,"w_uu":1,"w_pop":0}
    "quality_ndcg@10": 0.021691,
{"w_ii":0,"w_uu":0,"w_pop":1}
    "quality_ndcg@10": 0.014422,
{"w_ii":1,"w_uu":1,"w_pop":0.1}
    "quality_ndcg@10": 0.021803,
{"w_ii":1,"w_uu":0.5,"w_pop":0.3}
    "quality_ndcg@10": 0.022385,
Harness context total tokens reminder
{
  "type": "total_tokens_reminder",
  "text": "<total_tokens>14961201 tokens left</total_tokens>"
}
Harness context batching reminder sent
{
  "type": "batching_reminder_sent",
  "text": "First privately list what you need next; then request every item that doesn't depend on another's result in this one response.",
  "model": "claude-fable-5-1",
  "clearAt": "next_user_message"
}
12

Sweep more blend weights, check test build

+11:40
Recorded reasoning 22 words

User-user alone seems strong, so I'll try increasing the weight on the uu and popularity signals, then check the test build status.

Tool callBashSweep more blend weights, check test build Returned

Tool call · Input

tail -2 build_test.log; for p in '{"w_ii":0.5,"w_uu":1,"w_pop":0.3}' '{"w_ii":0.3,"w_uu":1,"w_pop":0.5}' '{"w_ii":0.5,"w_uu":1,"w_pop":0.6}' '{"w_ii":0,"w_uu":1,"w_pop":0.4}'; do echo "$p"; python blend.py val "$p" >/dev/null && python /task/evaluate_public.py validation.parquet | grep ndcg; done; tail -2 build_test.log

Options

{
  "timeout": 600000
}

Tool response

loaded 0.9445192813873291 cutoff 25393395
matrix (9978, 637419) 9026209 5.825517654418945 maxrss GB 4.048844
{"w_ii":0.5,"w_uu":1,"w_pop":0.3}
    "quality_ndcg@10": 0.021991,
{"w_ii":0.3,"w_uu":1,"w_pop":0.5}
    "quality_ndcg@10": 0.022252,
{"w_ii":0.5,"w_uu":1,"w_pop":0.6}
    "quality_ndcg@10": 0.022159,
{"w_ii":0,"w_uu":1,"w_pop":0.4}
    "quality_ndcg@10": 0.022221,
loaded 0.9445192813873291 cutoff 25393395
matrix (9978, 637419) 9026209 5.825517654418945 maxrss GB 4.048844
Harness context total tokens reminder
{
  "type": "total_tokens_reminder",
  "text": "<total_tokens>14960616 tokens left</total_tokens>"
}
Harness context batching reminder sent
{
  "type": "batching_reminder_sent",
  "text": "First privately list what you need next; then request every item that doesn't depend on another's result in this one response.",
  "model": "claude-fable-5-1",
  "clearAt": "next_user_message"
}
13

Final small blend sweep and check test build

+12:12
Recorded reasoning 53 words

The differences between configurations are tiny, around 0.022, with the best so far being w_ii=1, w_uu=0.5, w_pop=0.3 scoring 0.022385. With about 10 minutes left and the test build nearly done, I'll squeeze in one more quick parameter sweep while waiting, then lock in the best params, verify the submission, and write the README.

Model text

Best so far is item-item 1.0, user-user 0.5, popularity 0.3. I'll run two more nearby points while the test refit finishes, then write the submission.

Tool callBashFinal small blend sweep and check test build Returned

Tool call · Input

for p in '{"w_ii":1,"w_uu":0.7,"w_pop":0.3}' '{"w_ii":1,"w_uu":0.5,"w_pop":0.5}'; do echo "$p"; python blend.py val "$p" >/dev/null && python /task/evaluate_public.py validation.parquet | grep ndcg; done; tail -2 build_test.log

Options

{
  "timeout": 600000
}

Tool response

{"w_ii":1,"w_uu":0.7,"w_pop":0.3}
    "quality_ndcg@10": 0.022084,
{"w_ii":1,"w_uu":0.5,"w_pop":0.5}
    "quality_ndcg@10": 0.022638,
loaded 0.9445192813873291 cutoff 25393395
matrix (9978, 637419) 9026209 5.825517654418945 maxrss GB 4.048844
Harness context total tokens reminder
{
  "type": "total_tokens_reminder",
  "text": "<total_tokens>14959816 tokens left</total_tokens>"
}
Harness context batching reminder sent
{
  "type": "batching_reminder_sent",
  "text": "First privately list what you need next; then request every item that doesn't depend on another's result in this one response.",
  "model": "claude-fable-5-1",
  "clearAt": "next_user_message"
}
14

Check whether the test build is still running

+12:32
Recorded reasoning 42 words

The test build seems stuck at the matrix stage, started about 4 minutes ago, and the item-item validation run took 90 seconds — possibly slowed by memory or CPU contention from my parallel blend runs. I should check whether it's still alive.

Tool callBashCheck whether the test build is still running Error

Tool call · Input

ps aux | grep "build.py test" | grep -v grep | awk '{print $2,$3,$4,$6/1e6" GB"}'; tail -1 build_test.log; ls -la cache_test 2>/dev/null

Tool response · Tool error

Exit code 2
matrix (9978, 637419) 9026209 5.825517654418945 maxrss GB 4.048844
Harness context total tokens reminder
{
  "type": "total_tokens_reminder",
  "text": "<total_tokens>14959402 tokens left</total_tokens>"
}
Harness context batching reminder sent
{
  "type": "batching_reminder_sent",
  "text": "First privately list what you need next; then request every item that doesn't depend on another's result in this one response.",
  "model": "claude-fable-5-1",
  "clearAt": "next_user_message"
}
15

Refit on train+val, write submission, validate structure

+12:38
Recorded reasoning 51 words

The process likely died from running out of memory with those parallel blend runs each eating up ~3GB. I should rerun the test build now with nothing else running in the foreground, waiting for it to finish since it only takes about 2 minutes and I've used roughly 22 so far.

Model text

The background test build was killed, likely by memory pressure from the parallel sweeps. Rerunning it alone in the foreground now.

Tool callBashRefit on train+val, write submission, validate structure Returned

Tool call · Input

python -u build.py test 2>&1 | tail -4 && python blend.py test '{"w_ii":1,"w_uu":0.5,"w_pop":0.5}' && python - <<'EOF'
import pandas as pd, numpy as np
s = pd.read_parquet('/app/solution/submission.parquet'); t = pd.read_parquet('/task/data/target_users.parquet')
z = np.load('/task/data/test_eligible_candidates.npz'); m = np.unpackbits(z['packed_eligible'], axis=1, count=len(z['item_ids']), bitorder='little').astype(bool)
up = pd.Series(np.arange(len(z['uids'])), index=z['uids']); ip = pd.Series(np.arange(len(z['item_ids'])), index=z['item_ids'])
print('rows', len(s), 'users', s.uid.nunique(), 'targets', len(t), 'all targets covered', set(s.uid) == set(t.uid))
print('100 per user', (s.groupby('uid').size() == 100).all(), 'ranks ok', (s.groupby('uid')['rank'].apply(lambda r: sorted(r) == list(range(1, 101)))).all())
print('no dup items', not s.duplicated(['uid', 'item_id']).any(), 'all eligible', m[up[s.uid].values, ip[s.item_id].values].all())
EOF

Options

{
  "timeout": 600000
}

Tool response

matrix (9978, 637419) 9026209 5.78813910484314 maxrss GB 4.046628
item-item done 97.43307781219482
user-user done 114.97942638397217
cached components 124.72286939620972
wrote submission.parquet
rows 845600 users 8456 targets 8456 all targets covered True
100 per user True ranks ok True
no dup items True all eligible True
Harness context total tokens reminder
{
  "type": "total_tokens_reminder",
  "text": "<total_tokens>14958628 tokens left</total_tokens>"
}
Harness context batching reminder sent
{
  "type": "batching_reminder_sent",
  "text": "First privately list what you need next; then request every item that doesn't depend on another's result in this one response.",
  "model": "claude-fable-5-1",
  "clearAt": "next_user_message"
}
16

Write README and list solution directory

+14:59

Model text

The final submission is written and structurally valid. I'll finish with the README and a quick listing of the solution directory.

Tool callBashWrite README and list solution directory Returned

Tool call · Input

cat > README.md <<'EOF'
# Made-for-You discovery ranker

Eligible candidates exclude every track the user has already listened to, liked
or disliked, so this is a pure discovery task solved with neighbourhood
collaborative filtering (numpy/scipy only, fits in the 8 GB limit).

## Model (`build.py`)
1. Interaction matrix over all users x all items: listens with >=50% completion
   (weight 1, x1.5 if organic), likes (+3), dislikes (-2), each decayed with a
   60-day half-life to the cutoff; per-pair sums are signed-log compressed.
2. **Item-item cosine** scores on the 30k catalog items, computed in factored
   form `(X_u D X^T)(X D)` so no 30k x 30k matrix is ever materialised.
3. **User-user cosine** over the full item space (top-200 neighbours per target
   user), propagated to catalog items.
4. **Popularity prior**: log of organic >=80% listens + 3x organic likes in the
   last 30 days before the cutoff.
Components are cached under `cache_<stage>/`.

## Blend (`blend.py`)
Per-user z-scored components combined as `1.0*item_item + 0.5*user_user +
0.5*popularity`, ineligible items masked, top-100 written.

## Validation (train_* history only, scored by /task/evaluate_public.py)
| blend | NDCG@10 |
| --- | --- |
| item-item only | 0.0173 |
| user-user only | 0.0217 |
| popularity only | 0.0144 |
| 1.0 / 0.5 / 0.5 (selected) | 0.0226 |

## Reproduce
```sh
python build.py val  && python blend.py val  '{"w_ii":1,"w_uu":0.5,"w_pop":0.5}'   # validation.parquet
python build.py test && python blend.py test '{"w_ii":1,"w_uu":0.5,"w_pop":0.5}'  # submission.parquet (refit on train+val)
```
Each build stage takes ~2 minutes; run them one at a time (memory).
EOF
ls -la /app/solution

Tool response

total 3260
drwxr-xr-x 1 agent agent    4096 Oct  3 10:11 .
drwxr-xr-x 1 agent agent    4096 Oct  3 09:53 ..
-rw-r--r-- 1 agent agent    1650 Oct  3 10:11 README.md
-rw-r--r-- 1 agent agent    1479 Oct  3 10:05 blend.py
-rw-r--r-- 1 agent agent    5489 Oct  3 10:05 build.py
-rw-r--r-- 1 agent agent     109 Oct  3 10:07 build_test.log
drwxr-xr-x 2 agent agent    4096 Oct  3 10:11 cache_test
drwxr-xr-x 2 agent agent    4096 Oct  3 10:07 cache_val
-rw-r--r-- 1 agent agent 1646065 Oct  3 10:11 submission.parquet
-rw-r--r-- 1 agent agent 1647044 Oct  3 10:09 validation.parquet
Harness context total tokens reminder
{
  "type": "total_tokens_reminder",
  "text": "<total_tokens>14957624 tokens left</total_tokens>"
}
Harness context batching reminder sent
{
  "type": "batching_reminder_sent",
  "text": "First privately list what you need next; then request every item that doesn't depend on another's result in this one response.",
  "model": "claude-fable-5-1",
  "clearAt": "next_user_message"
}
17

Final response

+15:21

Model text

The submission is complete and verified at /app/solution/submission.parquet.

What the data showed. Eligible candidates exclude every track a user has already listened to, liked, or disliked. That makes this a pure discovery problem, so user history features on the candidate itself are useless and collaborative filtering is the whole game.

Model. A neighbourhood collaborative-filtering blend built with numpy and scipy only:

  • A time-decayed, signed interaction matrix from listens at 50%+ completion, likes, and dislikes, with organic listens weighted higher.
  • Item-item cosine scores on the catalog, computed in a factored form so the 30k×30k similarity matrix is never materialised. This was necessary to fit the 8 GB memory limit.
  • User-user cosine scores over the full item space with 200 neighbours per user.
  • A recent organic popularity prior.
  • Per-user z-scored components blended with weights 1.0, 0.5, and 0.5.

Validation results from the public evaluator, using train-only history:

BlendNDCG@10
item-item only0.0173
user-user only0.0217
popularity only0.0144
selected blend0.0226

Final artifact. The selected approach was refit on train plus validation events and written as 845,600 rows. I verified it covers all 8,456 target users with exactly 100 rows each, ranks 1 through 100 without ties, no duplicate items, and every item eligible in the test candidate set.

Files in /app/solution. The build script computes and caches score components per stage, the blend script produces a ranking from cached components, and the README documents the approach and reproduction commands.

One caveat: the background test refit was killed once by memory pressure when I ran blend sweeps in parallel. The successful refit was run alone, and the README notes that build stages should run one at a time.

Recorded session usage
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    "totalCostUSD": 1.402321,
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About this recording

The full recorded conversation: task prompt, agent messages, thinking text when available, tool inputs and outputs, and harness context. Empty thinking entries are labeled unavailable, not reconstructed from tool calls. Disclosures change the view; they do not shorten the content. Any truncation already present in tool output is preserved.

Steps follow the recorded model messages and reasoning events. Tool results appear with their originating call. Elapsed time starts with the first recorded event and excludes verification.

Attempt
fable51-high-2-1-288-basic-r05-20261003T075109Z
Recorded model
claude-fable-5-1
Harness version
2.1.288
Session
677e1a0e-99c0-47f1-915b-310de1994e9f
Source SHA-256
a7a4e937fe784224965b07472625b46b208f4d756eea788851b2f965219e8646

Session bookkeeping and encrypted reasoning or signatures are excluded from the reading export. The harness’s system prompt is not present in this session archive.