Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add Helweg/open-codebase-index --skill codebase-searchgit clone --depth 1 https://github.com/Helweg/open-codebase-indexWrote 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/skills/helweg/open-codebase-index/codebase-search)<a href="https://agentmods.dev/skills/helweg/open-codebase-index/codebase-search"><img src="https://agentmods.dev/badge/skills/helweg/open-codebase-index/codebase-search/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/skills/helweg/open-codebase-index/codebase-search"><img src="https://agentmods.dev/badge/skills/helweg/open-codebase-index/codebase-search.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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 | $0.00043 | $0.00707 |
| Opus 5.5 | $0.00017 | $0.00283 |
| Sonnet 5.5 | $0.00009 | $0.00141 |
| Haiku 4.5 | $0.00004 | $0.00071 |
Grade A, and why
codebase-search 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 14d 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 — 48 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Codebase Search Skill
Use this skill when you need local repository knowledge before web lookup.
Core workflow
- Run
index_statuswhen index readiness or freshness is unknown. - When repository orientation is needed (layout, relevant symbols, or cross-file intent), use one compact
codebase_context(query, tokenBudget: 600, limit: 5)first pass and inspect returned evidence before broad reads or searches. Do not call it mechanically before every task or tool. - For a known definition, use
implementation_lookup(query)directly. For callers or callees, usecall_graph(name, direction)directly; for relationships between identified endpoints, usecall_graph_path(from, to)directly. - For a change with a known or suspected target symbol, optionally use
codebase_edit_contextfor bounded target source plus direct callers and callees. - Use
codebase_peek(query, ...)when only semantic locations are needed, andcodebase_search(query, ...)when matching source content is needed. Neither requires another context call when the task is already scoped. - Read known paths directly and use
grepfor exact identifiers or exhaustive literal matches. Usefind_similar(code)for analogous implementations and duplicates.
Avoid repeating broad reads or retrieval when existing evidence already answers the question. If results are weak, check readiness, compatibility, and scope with index_status; run index_codebase only when the index is missing, stale, or incompatible.
Tool Priority
codebase_contextfor compact, unfamiliar-repository orientation; explicitsymbolandfrom+torouting remains supported.implementation_lookupfor known definitions.call_graphandcall_graph_pathfor relationships once symbols or endpoints are identified.codebase_edit_contextas an optional bounded pre-edit step.codebase_peekfor metadata-only semantic locations.codebase_searchfor matching implementation content.find_similarfor pattern matching and duplication.index_codebase(force/estimate/dryRun/verbose) for first-time or stale indexes.index_status,index_health_check,index_metrics,index_logsfor operational checks.
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.
- 14d ago Changed · +4 lines · +6 tokens per session 7ab8340bb174
- 1mo ago First seen · 44 lines · 37 tokens per session scan A 01b7766bf38e
codebase-search is a skill published in the GitHub repository Helweg/open-codebase-index (225 stars, last pushed yesterday), licensed MIT. It adds 43 tokens to every session and 707 once invoked, about $0.0002 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.
Other skills, from other repositories
cocosearch-refactoring
Use when planning a refactoring, extracting code into a new module, renaming across the codebase, or splitting a large file. Guides impact analysis and safe step-by-step execution using CocoSearch.
cocosearch-debugging
Use when debugging an error, unexpected behavior, or tracing how code flows through a system. Guides root cause analysis using CocoSearch semantic and symbol search.
cocosearch-deps
Use when exploring dependency relationships, tracing file connections, analyzing change impact, or identifying hub files. Guides dependency graph exploration using CocoSearch.
locus
npx @sylphx/locus --root=/absolute/path/to/project.
grepai-trace-graph
Build complete call graphs with GrepAI trace. Use this skill for recursive dependency analysis.
grepai-troubleshooting
Troubleshooting guide for GrepAI. Use this skill to diagnose and fix common issues.