@spiderbrain/read

@spiderbrain/read

Use a repo's committed SpiderBrain understanding, offline. When a repo carries a .spiderbrain/ folder, this reads it and answers structural questions about the codebase with zero setup: what a change reaches (blast radius), which files are load-bearing (keystones), and how any file fits. No account, no SpiderBrain install. MIT, zero dependencies.

Use it in one line

As an MCP server for your AI coding agent (Claude Code, Cursor):

npx @spiderbrain/read mcp

Tools: sb_blast, sb_keystones, sb_map, sb_ask. Your agent can now ask what a change reaches and what matters, from the committed graph, deterministically.

One-off from the terminal:

npx @spiderbrain/read blast src/server/health.ts   # what a change here reaches
npx @spiderbrain/read keystones                     # the load-bearing files
npx @spiderbrain/read map src/auth/session.ts       # what a file is + touches

What is offline vs cloud

• Offline (free, deterministic, from the committed .spiderbrain/ bytes): structure, dependencies, blast radius, keystones. Same question, same repo, same answer, byte for byte.
• Cloud (set SPIDERBRAIN_API_KEY): the why-layer (the decision behind a file), always-fresh scores, and semantic search. Get a key at https://spiderbrain.ai/dashboard?tab=keys.

export SPIDERBRAIN_API_KEY=sb_live_...
npx @spiderbrain/read why src/billing/charge.ts     # the decision + reasoning

Integrity

Every folder carries a fingerprint in manifest.json. The reader recomputes it from structure.ndjson on load; a hand-edited or corrupted folder reports a mismatch, so the map you query is the map that was published.

What it does not contain

The public understanding set is source-free: file paths, structure, and an edge-derivable blast radius only. Never your source code, never the scoring weights. See the repo's .spiderbrain/manifest.json for the exact contents.