MCP Servers
External context always available to every session.
Six MCP servers are pre-configured and always available. They're lazy-loaded via ToolSearch to keep context lean — discovered and called on demand. Add your own in .mcp.json, then run /setup-rules to generate documentation.
context7
Library documentation lookup
Get up-to-date API docs and code examples for any library or framework. Two-step: resolve the library ID, then query for specific documentation.
resolve-library-id(libraryName="react")
query-docs(libraryId="/npm/react", query="useEffect cleanup")
mem-search
Persistent memory search
Recall decisions, discoveries, and context from past sessions. Three-layer workflow: search → timeline → get_observations for token efficiency.
search(query="authentication flow", limit=5)
timeline(anchor=22865, depth_before=3)
get_observations(ids=[22865, 22866])
web-search
Web search + article fetching
Web search via DuckDuckGo, Bing, and Exa (no API keys needed). Also fetches GitHub READMEs, Linux.do articles, and other content sources.
search(query="React Server Components 2026", limit=5)
fetchGithubReadme(url="https://github.com/org/repo")
grep-mcp
GitHub code search
Find real-world code examples from 1M+ public repositories. Search by literal code patterns, filter by language, repo, or file path. Supports regex.
searchGitHub(query="useServerAction", language=["TypeScript"])
searchGitHub(query="FastMCP", language=["Python"])
web-fetch
Full web page fetching
Fetch complete web pages via Playwright (handles JS-rendered content, no truncation). Fetches single or multiple URLs in one call.
fetch_url(url="https://docs.example.com/api")
fetch_urls(urls=["https://a.com", "https://b.com"])
CodeGraph
Code knowledge graph and structural analysis
Builds a semantic knowledge graph of your codebase — functions, classes, call chains, and dependencies. Complements Probe CLI: Probe finds code by intent ("how does auth work?"), CodeGraph finds by structure ("who calls this function?", "what's affected by changing this?").
codegraph_search(query="Handler", kind="function")
codegraph_callers(symbol="processOrder")
codegraph_callees(symbol="processOrder")
codegraph_impact(symbol="processOrder", depth=2)
codegraph_context(task="refactor authentication flow")
Key capabilities:
| Tool | Use case |
|---|---|
codegraph_search | Find symbols by name — functions, classes, types |
codegraph_callers | Who calls X? Complete caller list with file locations |
codegraph_callees | What does X call? All downstream dependencies |
codegraph_impact | Blast radius — transitive callers and callees affected by a change |
codegraph_context | Task-driven context retrieval — entry points, related symbols, and code |
codegraph_node | Get details and source code for a specific symbol |
When to use Probe vs CodeGraph:
| Question | Best tool |
|---|---|
| "How does authentication work?" | Probe — natural language, intent-based search |
| "Who calls this function?" | CodeGraph — codegraph_callers with exact caller list |
| "What's the blast radius of my changes?" | CodeGraph — codegraph_impact shows transitive affected symbols |
| "Find functions matching a name" | CodeGraph — codegraph_search with kind filter |
| "Get context for a task" | CodeGraph — codegraph_context returns entry points and related code |
| "Extract a specific function's source" | Both — Probe extract for line/symbol, CodeGraph codegraph_node for symbol details |
Rules specify the preferred order — Probe CLI first for intent-based codebase questions, CodeGraph for structural queries (call tracing, impact analysis), context7 for library API lookups, grep-mcp for production code examples, web-search for current information. The tool_redirect.py hook blocks the built-in WebSearch/WebFetch and the Explore agent, redirecting to these alternatives.