A VS Code chat participant (@tecr) that lets AI agents navigate your codebase without dumping raw source into the context window. It talks to a local tecr-mcp server over the Model Context Protocol, providing AST-aware tools that stay within configurable token budgets.
Why TECR vs. your IDE's built-in AI?
Modern IDE AI (Copilot, Cursor)
TECR
Context strategy
Dumps nearby files into the prompt
Fetches only what the task needs
Token awareness
None — host model manages cutoff
Tracks utilization per turn; governor blocks before hard stop
Code navigation
Embedding similarity or whole-file send
AST-ranked repo map, symbol search, paginated reads with cursor
Exploratory tasks
Pollutes the parent context
Isolated sub-agent; only a ≤200-token summary returns
Protocol
Proprietary IDE integration
MCP — works in any compliant host
Context window use
Grows until truncated by the model
Stays within a declared budget; truncation is a metric, not a surprise
Prerequisites
VS Code 1.99 or later (chat participant API)
Node.js ≥ 20
Quick start
Install the MCP server globally:
npm install -g @tecr/mcp
Install the extension from the VS Code Marketplace (search TECR) or via Extensions → Install from VSIX…
Reload the window (⌘⇧P → Developer: Reload Window)
Open the chat panel and type @tecr map
No path configuration needed — the extension finds tecr-mcp on your PATH automatically.
Development / local checkout: Set tecr.mcpServerPath to the absolute path of packages/tecr-mcp/dist/index.js to override the global binary.
Commands
Command
Description
@tecr map [budget]
Repo-map of the workspace (default 8192 tokens). Budget in tokens.
@tecr outline <file>
Exported symbols and docstrings for a file
@tecr read <file> [start] [end]
Paginated file read with optional line range
@tecr search <query>
AST-aware symbol search across the workspace
@tecr grep <pattern>
Lexical search with ±2 lines of context (max 100 matches)
@tecr refs <symbol>
All call sites for a named symbol
@tecr delegate <task>
Isolated sub-agent discovery — result summary only enters parent context
Settings
Setting
Default
Description
tecr.mcpServerPath
""
Absolute path to tecr-mcp/dist/index.js
tecr.contextWindow
200000
Token budget for the TECR governor
tecr.localModelUrl
""
OpenAI-compatible endpoint for sub-agent offload (e.g. Ollama)
tecr.telemetryEnabled
true
Emit per-turn token metrics to the server's stderr
Troubleshooting
"TECR server not found" — The tecr.mcpServerPath setting is wrong or the server hasn't been built. Check the path and run pnpm --filter @tecr/mcp build.
Blank response — The server may have crashed. Open the Output panel (⌘⇧U) and select TECR, or check the Extension Host log for errors.
Slow first call — The server loads WASM parsers on startup. Subsequent calls are fast.
Known limitations
Only the first workspace folder is used as workspaceRoot. Multi-root workspaces are not yet supported.
@tecr delegate uses heuristic sub-agent routing. Set tecr.localModelUrl to route to a local LLM.
