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 skillgit 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/skill)<a href="https://agentmods.dev/skills/helweg/open-codebase-index/skill"><img src="https://agentmods.dev/badge/skills/helweg/open-codebase-index/skill/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/skill"><img src="https://agentmods.dev/badge/skills/helweg/open-codebase-index/skill.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 | $0.00038 | $0.01203 |
| Opus 5.5 | $0.00015 | $0.00481 |
| Sonnet 5.5 | $0.00008 | $0.00241 |
| Haiku 4.5 | $0.00004 | $0.00120 |
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 — 116 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Codebase Search Skill
Important: Indexed Content
The indexed codebase contains two types of content:
- Project Source Code — all code files in the current workspace
- Knowledge Base Documentation — external documentation, usage guides, API references, and example programs added via
add_knowledge_base(MCP/OpenCode) orknowledge_base_add(Pi).
When to Use What
| Scenario | Tool | Why |
|---|---|---|
| Unfamiliar repository layout or subsystem | codebase_context |
Compact orientation before broad reads |
| Code/library/API question | codebase_search |
Search local knowledge first |
| Just need file locations | codebase_peek |
Metadata only, saves ~90% tokens |
| Need to see actual code | codebase_search |
Returns full code content |
| Find duplicates/patterns | find_similar |
Given code snippet → similar code |
| Understand code flow | call_graph |
Find callers/callees of any function |
| Trace dependency paths | call_graph_path |
Find a shortest known path between two symbols |
| Analyze PR blast radius | pr_impact |
Find affected symbols, communities, hub nodes, and risk |
| Don't know function/class names | codebase_context |
Natural-language orientation with bounded evidence |
| Know a symbol and need its definition | implementation_lookup |
Authoritative source without a context prerequisite |
| Need ALL occurrences | grep |
Semantic returns top N only |
| Access specific URL | webfetch |
Direct URL access, no codebase search needed |
| Local search fails | websearch |
Fallback when codebase has no results |
| Local and web search fails | suggest adding knowledge base | Notify user to add related folder |
Task-specific Workflow
- Check
index_statuswhen readiness or freshness is unknown. Index only when missing, stale, or incompatible. - For unfamiliar repository orientation, use one compact
codebase_contextfirst pass (tokenBudget: 600,limit: 5) and inspect its evidence before broad reads or searches. - For known definitions, use
implementation_lookupdirectly. For callers/callees or dependency paths, usecall_graphorcall_graph_pathdirectly once endpoints are identified. - For known or suspected edit targets, optionally use
codebase_edit_contextfor bounded source plus direct graph evidence. - Use
codebase_peekfor semantic locations orcodebase_searchfor matching content when needed. Neither requires another context call when scope is already known. - Read known paths directly; use
grepfor exact identifiers and exhaustive literal matches. Apply directory/file filters when the scope is known, rather than guessing a narrower scope.
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 · -20 lines · -20 tokens per session 874f5de80503
- 17d ago Changed 18e32aee6b20
- 1mo ago First seen · 136 lines · 58 tokens per session scan A f228e71218b0
codebase-search is a skill published in the GitHub repository Helweg/open-codebase-index (225 stars, last pushed yesterday), licensed MIT. It adds 38 tokens to every session and 1,203 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.