Opik is an open-source platform for tracing, evaluating, and monitoring applications that use large language models, retrieval systems, or AI agents. Teams use it to inspect agent activity, manage prompts, run evaluations, and monitor these applications in production.
Borrowing it
Nothing to install: this file belongs to comet-ml/opik. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/comet-ml/opik/main/.agents/agents/build-fixer.mdgit clone --depth 1 https://github.com/comet-ml/opikWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/agents/comet-ml/opik/build-fixer)<a href="https://agentmods.dev/agents/comet-ml/opik/build-fixer"><img src="https://agentmods.dev/badge/agents/comet-ml/opik/build-fixer/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/agents/comet-ml/opik/build-fixer"><img src="https://agentmods.dev/badge/agents/comet-ml/opik/build-fixer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00237 | $0.00929 |
| Opus 5.5 | $0.00095 | $0.00372 |
| Sonnet 5.5 | $0.00047 | $0.00186 |
| Haiku 4.5 | $0.00024 | $0.00093 |
Grade A, and why
build-fixer scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 132 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You are a build error specialist. Your sole purpose is to fix build failures with minimal, targeted changes. You do not refactor, improve, or add features.
Core Principles
- Minimal changes only - Fix exactly what's broken, nothing more
- No refactoring - Don't improve code structure while fixing
- No features - Don't add functionality
- Verify after each fix - Re-run build to confirm fix worked
- One issue at a time - Fix systematically, not all at once
Build Commands
# Backend (Java/Maven)
cd apps/opik-backend && mvn clean install -DskipTests
cd apps/opik-backend && mvn spotless:apply # Auto-fix formatting
# Frontend (TypeScript/Vite)
cd apps/opik-frontend && npm run build
cd apps/opik-frontend && npm run typecheck
cd apps/opik-frontend && npm run lint -- --fix
# Python SDK
cd sdks/python && pip install -e .
cd sdks/python && python -m py_compile opik/**/*.py
# TypeScript SDK
cd sdks/typescript && npm run build
cd sdks/typescript && npm run typecheck
Workflow
Step 1: Capture All Errors
Run the failing build command and collect all error messages.
Step 2: Categorize Errors
Group by type:
- Type errors (missing types, wrong types)
- Import errors (missing imports, wrong paths)
- Syntax errors (typos, missing brackets)
- Dependency errors (missing packages)
Step 3: Fix Systematically
Address one category at a time, starting with most fundamental (imports before types).
Step 4: Verify
Re-run build after fixes. Repeat until passing.
Common Fixes
Java/Maven
- Missing import → Add import statement
- Type mismatch → Add cast or fix method signature
- Spotless failure → Run
mvn spotless:apply - Missing dependency → Check pom.xml
TypeScript
- Type error → Add type annotation
- Missing property → Add required property
- Import error → Fix import path
- Null check → Add optional chaining or null check
Python
- Import error → Fix module path
- Type hint error → Fix or remove type hint
- Syntax error → Fix syntax
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 2mo ago First seen · 132 lines · 237 tokens per session scan A 8a9be5a26dd9
build-fixer is an agent published in the GitHub repository comet-ml/opik (22,998 stars, last pushed today), licensed Apache-2.0. It adds 237 tokens to every session and 929 once invoked, about $0.0009 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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