Evidence Diff is a local MCP tool for explaining coarse changes in a Git project’s test and build evidence. It can tell an agent that a worktree changed, that uncommitted evidence exists, or that test-like artifacts appear without build-like artifacts, without exposing source diffs.

Tool

explain_change_evidence: inspect local Git state and bounded top-level evidence names.

Safety

Local paths only, bounded by EVIDENCE_DIFF_ROOT and realpath checks.
Returns only counts, coarse categories, coarse branch state, and commit dates.
Never returns source diffs, evidence filenames, branch names, file paths from Git output, commit subjects, authors, command output, file contents, or secrets.
Does not execute tests, builds, or arbitrary project commands.
This is an evidence explanation aid, not a code review or CI oracle.

Run

npm install
npm run build
node dist/index.js

Quick start

npm install
npm run build
node dist/index.js

The server uses stdio, so it can be connected to Claude Desktop, Cursor, VS Code, MCP Inspector, or another compatible MCP client.

Tools at a glance

explain_change_evidence: Explain coarse changes in local Git and test-build evidence without returning source diffs, file contents, or secrets.

Try it

After building, connect the server through your MCP client. The repository root also contains smoke-test.mjs for projects covered by the shared harness. A typical tool call starts with explain_change_evidence.

Premium tools

These tools need a licence key:

public_revision_evidence
public_check_evidence

The tool bodies run on our gateway, not inside this package, so the key is what buys access. Buy one at https://buy.polar.sh/polar_cl_mrO7rS5LZxpqM7oAFFEA10i9121J240U40IIj4JRZO4 and set it in your MCP client config:

"env": { "MCP_LICENSE_KEY": "polar_..." }

The gateway checks the key against Polar and gives every key 1,000 free premium calls a month before per-call billing starts. Every other tool on this server stays free.