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Spiderbrain

Spiderbrain

Remote
spiderbrain.aiDeveloper Tools3Updated 10w ago
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About Spiderbrain

Spiderbrain creates a committed, source-free understanding layer for code repositories. Developers and coding agents can query change impact, file relationships, and key files through its CLI or MCP server, including offline from the repository data.

Key features

  1. 01Create committed repository context
  2. 02Analyze change blast radius
  3. 03Trace paths between files
  4. 04Identify load-bearing files
  5. 05Verify context integrity

Use cases

  1. 01Assess the reach of a source file change
  2. 02Review the impact of a current Git diff
  3. 03Trace how two files are connected
  4. 04Check committed context in CI

MCP support

The `spiderbrain mcp` command runs an MCP server that serves a repository’s `.spiderbrain/` understanding layer to clients such as Claude Code and Cursor. Set `--root` or `SPIDERBRAIN_ROOT` to identify the repository.

Configuration

Remote servers need no local install. Pick your client, then copy the config or install in one click.

Endpointhttps://mcp.spiderbrain.ai/mcp
Copy install command
Claude CodeTerminal
Cursor.cursor/mcp.json
VS Code.vscode/mcp.json
Claude Desktopclaude_desktop_config.json
Windsurf~/.codeium/windsurf/mcp_config.json

Run commands in a terminal; paste JSON into the client’s MCP config and restart. Servers that need sign-in will prompt on first connect.

All endpoints
Streamable HTTPhttps://mcp.spiderbrain.ai/mcpAuth required
Packages
npmspiderbrain0.2.3

Tools

Details

From the project README

spiderbrain

A committed understanding layer for your repo, and the one command to work with it. A repo tells an AI agent what the code is; it never tells it what matters, what a change reaches, or why anything was built the way it was. spiderbrain fixes that.

Give a repo understanding

export SPIDERBRAIN_API_KEY=sb_live_...     # https://spiderbrain.ai/dashboard?tab=keys
npx spiderbrain create

Writes a source-free .spiderbrain/ folder and an AGENTS.md block. Commit both.

Read a repo's understanding (no account needed)

When a repo has a .spiderbrain/ folder, any agent or developer can use it offline:

npx spiderbrain mcp --root .        # an MCP server for Claude Code / Cursor
npx spiderbrain blast src/db.ts     # what a change here reaches
npx spiderbrain impact              # what your current git diff reaches
npx spiderbrain keystones           # the load-bearing files
npx spiderbrain path a.ts b.ts      # how one file reaches another
npx spiderbrain verify --allow-stale   # folder untampered? (CI gate)

An MCP client's working directory is usually not your repository, so pass the repo explicitly with --root <path>, --root=<path>, or the SPIDERBRAIN_ROOT environment variable. Without it the server serves the working directory and reports that no understanding layer was found, which is a wrong answer rather than an error.

Every command takes --json (exit codes: 0 ok, 1 failed, 2 usage, 3 no understanding). No committed folder? The reader falls back to the public registry when the repo's origin has an unofficial brain there.

The pieces

spiderbrain is a thin dispatcher over two independently installable packages:

A CI job that only publishes understanding can depend on @spiderbrain/create alone; an MCP config that only reads can point at @spiderbrain/read. spiderbrain is what you type when you just want the thing.

License

MIT.

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