Diffctx MCP Server

diffctx selects the minimum code an LLM needs to review a git diff. Instead of pasting whole files, it walks the dependency graph outward from the changed lines and stops once more context stops paying for itself. It runs locally over stdio via the published package.

People who work with code context, developer tools and prompt engineering and want it reachable from Claude, Cursor, VS Code, or another MCP client. The project is written in Rust.

VERIFIED ACTIVE

LAST COMMIT 2026-09-17 · ★ 4 · #59 OF 168 MAINTAINED DEVELOPER TOOLS · VERIFIED 2026-09-18

Apache-2.0 · Rust servers · how we verify → /methodology

01 · Install Diffctx

before you install - you'll need

The README does not document required environment variables for a basic install.

Claude Code

claude mcp add nikolay-e-diffctx -- uvx diffctx

Claude Desktop / Cursor / VS Code - add to config

{
  "mcpServers": {
    "nikolay-e-diffctx": {
      "command": "uvx",
      "args": [
        "diffctx"
      ]
    }
  }
}

Same JSON for Cursor. For VS Code, rename the top-level key from `mcpServers` to `servers`.

Using another client? Same JSON, different key

Claude Desktop · mcpServers

Cursor · mcpServers

VS Code · servers

Windsurf · mcpServers

Zed · context_servers

Cline · mcpServers

Roo Code · mcpServers

Continue · mcpServers

LibreChat · mcpServers

Gemini CLI · mcpServers

Codex CLI · mcp_servers

Full setup guides: every client.

02 · Evidence

Security posture

What to check before giving this server access to your agent - from the registry, GitHub, and our own probes. We don't score safety; we show what's verifiable.

runs as local process (stdio) - runs on your machine with your user's permissions

license Apache-2.0 - declared in the repository

pypi package diffctx - check the name against the project README before installing (PyPI has no namespace ownership)

registry namespace io.github.nikolay-e is GitHub-verified and matches the repo owner

03 · What Diffctx can do

Prose above is summarized from the project's README and registry record - no invented capabilities.

Latest releases

v1.16.0 · 2026-09-16

chore(deps)(deps): bump anchore/sbom-action from 0.24.0 to 0.24.1 in the all-dependencies group · dogfood - pin diffctx's review context to every pull request · chore(deps)(deps): bump the all-dependencies group across…

v1.15.0 · 2026-08-29

v1.14.0 · 2026-08-16

chore(deps)(deps): bump similar from 3.1.1 to 3.1.2 · chore(deps)(deps): bump clap from 4.6.4 to 4.6.5 · chore(deps)(deps): bump pyo3 from 0.29.0 to 0.29.2 · chore(deps)(deps): bump aho-corasick from 1.1.4 to 1.1.5…

04 · Who maintains Diffctx

diffctx is maintained by nikolay-e. It's the only MCP server we track from this author; the repo dates to Oct 2024.

05 · Facts

repository: github.com/nikolay-e/diffctx
website: https://nikolay-e.github.io/diffctx/
category: developer tools - ranked #59 of 168 actively-maintained developer tools servers as of 2026-09-18.
release cadence: 7 releases in the last 90 days (latest 2026-09-16)
registry: io.github.nikolay-e/diffctx (active, first published 2026-07-26 · 6 versions)
packages: pypi:diffctx

06 · Diffctx FAQ

What is Diffctx?

Is Diffctx still maintained?

Yes - as of 2026-09-18, its last commit was 2026-09-17 and it shipped 7 releases in the last 90 days. We re-verify nightly.

How do I install Diffctx?

Run `uvx diffctx`. The README does not document required environment variables for a basic install. You can also paste the ready-made client config above.

Does Diffctx run locally?

Yes - it's a stdio server: it runs on your machine (via uvx) with your user's permissions. Your data stays local unless the server itself calls external APIs.

07 · Alternatives to Diffctx

Alternatives to Diffctx

Maintained developer tools servers if Diffctx isn't the fit.

Pairs well with

Servers that cover what Diffctx doesn't - only shown when the pairing reason fits the companion.

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