What is SigMap?
SigMap extracts a compact signature map of your entire codebase — function names, class hierarchies, exported types, interfaces — and writes it to .github/copilot-instructions.md automatically.
Every AI coding assistant (GitHub Copilot, Claude, Cursor, Windsurf, Gemini, Codex) reads that file as its first-message context. Without it, the AI starts knowing nothing about your project. With SigMap, it starts with everything.
Before SigMap: "I don't know your codebase — can you share some files?"
After SigMap: "I can see your AuthService, UserRepository, 47 API routes…"
A 50,000-line TypeScript monorepo → ~3,800 tokens of pure signatures — a 96.8% average reduction across 18 real repos.
What's new in v4.2–v4.4
sigmap_query language model tool (v4.3) — Copilot agent mode calls SigMap's ranked retrieval automatically; reference it in chat as #sigmap- One-click MCP registration (v4.3) — the SigMap MCP server registers via VS Code's MCP provider API, no
mcp.json editing
- Multi-root workspaces (v4.4) — the active editor's folder drives the status bar, commands, and decorations
- In-editor query (v4.2) —
SigMap: Query Context shows ranked files in a QuickPick
- Hardened core loop (v4.2.1) — cached command resolution, throttled health probes, honest fallback grades, regenerate failure feedback
- Compatible with SigMap CLI v8.x: 33 languages, 20 MCP tools
Features
Live health grade in the status bar
| Grade |
Status bar |
Meaning |
| A |
sm: ✔ A 2h ago |
Fresh — AI has full context |
| B |
sm: ℹ B 6h ago |
Good |
| C |
sm: ⚠ C 1d ago |
Stale — regenerate soon |
| D |
sm: ✖ D 3d ago |
Very stale — regenerate now |
Click the status bar item for instant regeneration.
Other features
- Auto-regeneration — checks on startup and every 60 seconds
- Stale notifications — pop-up with one-click Regenerate after 24 h
- Secret scanning — AWS keys, tokens, DB strings auto-redacted before writing
- MCP server — 20 tools exposed over stdio JSON-RPC for Claude / Cursor / Copilot
- One-command context —
SigMap: Regenerate Context from the Command Palette
Installation
VS Code Marketplace (recommended)
Search "SigMap" in the Extensions panel, or:
ext install manojmallick.sigmap
Open VSX (VSCodium / Gitpod / Windsurf)
open-vsx.org/extension/manojmallick/sigmap
Manual (.vsix)
Download sigmap-X.Y.Z.vsix from Releases, then:
Extensions: Install from VSIX…
Quick start
# 1. Install the CLI
npm install -g sigmap
# 2. In VS Code: Ctrl+Shift+P → SigMap: Regenerate Context
# Or run directly:
npx sigmap
Then use the full workflow:
sigmap ask "where is auth handled?" # query-focused context
sigmap validate # check coverage
sigmap judge # score answer groundedness
sigmap --watch # auto-regenerate on save
Requirements
| Requirement |
Details |
| VS Code |
1.85.0 or higher |
| Node.js |
18 or higher |
| SigMap CLI |
npm install -g sigmap · npm install sigmap · npx sigmap · or standalone binary |
29 Language support
TypeScript · JavaScript · Python · Go · Rust · Java · C# · C/C++ · Ruby · PHP · Swift · Dart · Kotlin · Scala · Vue · Svelte · CSS/SCSS · GraphQL · SQL · Terraform · Protobuf · Markdown · TOML · XML · Properties · Dockerfile · and more.
Commands
| Command |
Description |
SigMap: Regenerate Context |
Run sigmap in your workspace root |
SigMap: Open Context File |
Open .github/copilot-instructions.md |
CLI reference
sigmap # generate once
sigmap ask "<query>" # ranked context for a specific task
sigmap validate # check coverage health
sigmap judge # groundedness score for an AI answer
sigmap --watch # auto-regenerate on file changes
sigmap --health # 0–100 health score
sigmap --mcp # start MCP server (20 tools)
sigmap --diff # context for changed files only
Works with Claude Code, Cursor, and Copilot agent mode via sigmap --mcp (registered with one click by this extension). Key tools:
| Tool |
Description |
read_context |
Full or per-module signature map |
search_signatures |
Keyword search across all signatures |
get_map |
Import graph, class hierarchy, or route table |
query_context |
Graph-boosted ranked file retrieval |
create_checkpoint |
Session checkpoint with git state |
get_routing |
Model routing hints (fast/balanced/powerful) |
explain_file |
Signatures, imports, and callers for a file |
list_modules |
All modules sorted by token count |
get_impact |
Blast-radius BFS for a changed file |
…plus 11 more (squeeze_output, get_method_impact, memory/session tools, …) — see the docs for the full list.
Benchmark
| Metric |
Value |
| Retrieval hit@5 |
85.6% vs 13.6% random baseline (6.3×) |
| Honest grep-agent baseline |
42.7% → 85.6% (2.0× lift) |
| Overall token reduction |
96.8% (avg across 18 real repos) |
| Prompt reduction |
48% (2.84 → 1.48 prompts/task) |
| Task success proxy |
66.7% |
| Languages |
33 |
Benchmark ID: sigmap-v8.21-main · Date: 2026-07-19
Token reduction by repo
| Repo |
Language |
Reduction |
| express |
JavaScript |
98.7% |
| flask |
Python |
96.0% |
| gin |
Go |
96.7% |
| spring-petclinic |
Java |
99.2% |
| rails |
Ruby |
99.5% |
| rust-analyzer |
Rust |
99.8% |
| abseil-cpp |
C++ |
99.7% |
| laravel |
PHP |
99.6% |
| vue-core |
Vue |
97.8% |
Settings
| Setting |
Default |
Description |
sigmap.scriptPath |
"" |
Absolute path to gen-context.js. Leave empty to auto-detect. |
Troubleshooting
Status bar shows sm: no context
→ Run SigMap: Regenerate Context. Check Node 18+: node --version
"command not found"
→ npm install -g sigmap or set sigmap.scriptPath in settings
Copilot not using the context
→ File must be at .github/copilot-instructions.md in the workspace root
Want to exclude files?
→ Create .contextignore (gitignore syntax) in your project root
| Tool |
How |
| GitHub Copilot |
Reads .github/copilot-instructions.md automatically |
| Claude / Claude Code |
Add "outputs": ["claude"] to config → writes CLAUDE.md |
| Cursor |
Add "outputs": ["cursor"] → writes .cursorrules |
| Windsurf |
Add "outputs": ["windsurf"] → writes .windsurfrules |
| MCP (Claude/Cursor/Copilot) |
sigmap --mcp — 20 tools over stdio JSON-RPC (one-click registration via this extension) |
Links
MIT © 2026 Manoj Mallick · Made in Amsterdam 🇳🇱
SigMap for daily always-on context · Repomix for deep one-off sessions — use both.
