| name | librarian |
| description | Deep codebase exploration across remote repositories. Fetch, search, and compare library source code. Use for internals, architecture analysis, and cross-repo patterns. Skip simple API or docs questions. |
| references | ["references/tool-routing.md","references/opensrc-api.md","references/opensrc-examples.md","references/linking.md","references/diagrams.md"] |
Librarian Skill
Deep codebase exploration across remote repositories.
Non-Negotiables
- Use
source.name from fetch results for every subsequent opensrc call. Never re-derive it.
- Route simple API and docs questions to
context7 first. Use opensrc only for implementation internals.
- Return the final comprehensive answer in the last message only.
- Link every cited source file with a GitHub or GitLab URL. Follow
references/linking.md.
- Never mention internal tool names to the user.
How to Use This Skill
Reference Structure
| File | Purpose | When to Read |
|---|
tool-routing.md | Tool selection decision trees | Read first |
opensrc-api.md | opensrc-mcp codemode API surface | Writing exploration code |
opensrc-examples.md | Multi-step exploration workflows | Reusing proven patterns |
linking.md | GitHub and GitLab URL patterns | Formatting citations |
diagrams.md | Mermaid patterns | Visualizing architecture |
Reading Order
- Read
tool-routing.md.
- If the route uses opensrc, read
opensrc-api.md and opensrc-examples.md.
- Before the final answer, read
linking.md and diagrams.md.
Tool Arsenal
| Tool | Best For | Limitations |
|---|
| grep_app | Find patterns across public GitHub | Literal search only |
| context7 | Library docs, API examples, usage | Known libraries only |
| opensrc | Fetch full source for deep exploration | Fetch before read |
Quick Decision Trees
"How does X work?"
Known library?
├─ Yes → context7.resolve-library-id → context7.query-docs
│ └─ Need internals? → opensrc.fetch → read source
└─ No → grep_app search → opensrc.fetch top result
"Find pattern X"
Specific repo?
├─ Yes → opensrc.fetch → opensrc.grep → read matches
└─ No → grep_app search → opensrc.fetch interesting repos
"Explore repo structure"
1. opensrc.fetch(target)
2. opensrc.tree(source.name) → quick overview
3. opensrc.files(source.name, "**/*.ts") → detailed listing
4. Read README, package.json, src/index.*
5. Create architecture diagram from findings
"Compare X vs Y"
1. opensrc.fetch(["X", "Y"])
2. Capture source.name from each fetch result
3. opensrc.grep(pattern, { sources: [nameX, nameY] })
4. Read comparable files
5. Synthesize differences
Critical: Source Naming Convention
After fetching, use source.name for every later call:
const [{ source }] = await opensrc.fetch("vercel/ai");
const files = await opensrc.files(source.name, "**/*.ts");
| Type | Fetch Spec | Source Name |
|---|
| npm | "zod" | "zod" |
| npm scoped | "@tanstack/react-query" | "@tanstack/react-query" |
| pypi | "pypi:requests" | "requests" |
| crates | "crates:serde" | "serde" |
| GitHub | "vercel/ai" | "github.com/vercel/ai" |
| GitLab | "gitlab:org/repo" | "gitlab.com/org/repo" |
When Not to Use opensrc
| Scenario | Use Instead |
|---|
| Simple library API questions | context7 |
| Finding examples across many repos | grep_app |
| Very large monorepos (>10GB) | Clone locally |
| Private repositories | Direct access |
Output Format
- Return one comprehensive final answer in the last message only.
- Cite every file reference as a markdown link.
- Use comparison tables for cross-repo findings.
- Add diagrams for complex structure or flow.
- Describe actions generically. Do not expose internal tool names.
References
