| name | memtrace-api-topology |
| description | Always use for API endpoint, HTTP route, fetch/client call, REST surface, service dependency, cross-repo dependency, or API topology questions in source code. Do not use Grep, Glob, rg, find, or manual file search for routes or HTTP calls; Memtrace maps endpoints and call edges from the indexed AST graph. |
Overview
Map the HTTP API surface of a codebase — exposed endpoints, outbound HTTP calls, and cross-repo service-to-service dependency graphs. Supports auto-detection for Express, Encore, NestJS, Axum, FastAPI, Flask, Gin, Spring Boot, and more.
Quick Reference
| Tool | Purpose |
|---|
find_api_endpoints | All exposed HTTP endpoints (GET /users, POST /orders, etc.) |
find_api_calls | All outbound HTTP calls (fetch, axios, reqwest, etc.) |
get_api_topology | Cross-repo call graph: which service calls which endpoint |
link_repositories | Manually link repos for cross-repo edge detection |
Parameter types: MCP parameters are strictly typed. Numbers (limit, depth, min_size, last_n, etc.) must be JSON numbers — not strings. Use limit: 20, never limit: "20". Passing a string yields MCP error -32602: invalid type: string, expected usize.
Steps
1. Discover endpoints
Use find_api_endpoints:
repo_id — required- Returns: method, path, handler function, framework detected
2. Discover outbound calls
Use find_api_calls:
repo_id — required- Returns: target URL/path, HTTP method, calling function, library used (fetch, axios, reqwest, etc.)
3. Map service topology
Use get_api_topology to see the cross-repo HTTP call graph:
- Which services call which endpoints
- Confidence scores for each detected link
- Service-to-service dependency direction
Prerequisite: Multiple repos must be indexed. If cross-repo links aren't appearing, use link_repositories to explicitly connect them.
4. Deep-dive into an endpoint
For any specific endpoint, use get_symbol_context with the endpoint's symbol ID to see:
- Which internal functions handle the request
- Which processes (execution flows) include this endpoint
- Which external services call this endpoint
Common Mistakes
| Mistake | Reality |
|---|
| Expecting cross-repo links with only one repo indexed | Index ALL related services first; cross-repo HTTP edges are linked automatically after indexing |
| Missing endpoints from custom frameworks | Memtrace auto-detects major frameworks; for custom routers, the endpoints may appear as regular functions |
Not using link_repositories | If auto-linking missed a connection, use this to manually establish cross-repo edges |
