LayerMap MCP server

LayerMap

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LayerMap tells your coding agent what calls a function and what changing it affects, up to the HTTP routes, in one call. With at most 15 requests, agents found 97.9% of affected endpoints with LayerMap vs 58.8% without; with no limit, Claude Code cost 33% less in the 0.1.5 re-run (benchmark).

Resolved by each language's compiler or type checker, not guessed from names by tree-sitter: calls through interfaces, base classes, templates and decorators link as the compiler links them, for TypeScript, JavaScript, Go, Python and Java.

A real Claude Code session on Miniflux, replayed: one map call finds every endpoint, then the agent confirms them in source.

A layered map of your codebase for coding agents. LayerMap gives Claude Code, Codex, DeepSeek Harness and other MCP clients read-only tools that answer, in one call, what an agent otherwise works out with dozens of searches:

HTTP routes, handlers, jobs and commands they start from.

• What calls this, and what does changing it affect? Callers traced up to 8 levels, to the

existing tests related to them.

• What does it call? Callees down to 8 levels.
• What is here? Modules, each file's declarations, and every usage of a symbol.
• What did my edit affect? The routes, jobs and commands the uncommitted changes reach, and the

It maps TypeScript, JavaScript, Go, Python and Java with each language's own compiler, so calls through interfaces, base classes, templates and decorators resolve as the compiler resolves them, including the ones text search misses.

Example

In Miniflux, one call on Storage.MarkFeedAsRead finds all four ways a request reaches it, each with its route:

DECLARATION internal/storage/entry.go: Storage.MarkFeedAsRead m656-680 exported
  ← called by internal/api/feed.go: handler.markFeedAsRead m140-155 @149
  ← called by internal/fever/handler.go: handler.handleWriteFeeds m492-519 @508
  ← called by internal/googlereader/handler.go: handler.markAllAsReadHandler m1261-1338 @1311
  ← called by internal/ui/feed_mark_as_read.go: handler.markFeedAsRead m14-30 @24
[1] internal/api/feed.go: handler.markFeedAsRead m140-155
  ← used as value by internal/api/api.go: Serve f25-84 @61 "PUT /v1/feeds/{feedID}/mark-all-as-read"
[1] internal/googlereader/handler.go: handler.markAllAsReadHandler m1261-1338
  ← used as value by internal/googlereader/handler.go: Serve f44-64 @62 "POST /reader/api/0/mark-all-as-read"
[1] internal/ui/feed_mark_as_read.go: handler.markFeedAsRead m14-30
  ← used as value by internal/ui/ui.go: Serve f18-180 @77 "POST /feed/{feedID}/mark-all-as-read"
… (the Fever API, then on down to main.go: main)

Shortened. The full README is on GitHub.