diffctx

Name: diffctx
Author: nikolay-e

by nikolay-eversion 1.20.0i★ –iRuns on your computer

Registry nameio.github.nikolay-e/diffctx

Install

Overview

Description from the maker (original English)

Selects the minimum code an LLM needs to review a git diff

PopNx MCP’s three pillars

These three are never merged into one score: opinions, measurements and popularity are different things.

User voiceiNo reviews yetReviews open together with accounts in a later step
Our basic checksi1 of 1 passedChecked from public information; code not scanned yet
UsageiNot measured yet★ –

What you can do with it

We have not written a plain-language summary for this one yet. Below are the facts we read from the registry.

Connection: Runs on your computer
Transport: stdio
Category: Search & AI memory

Install

Pick the AI app you use, then copy the settings.

Before you install

Basic checks: 1 of 1 passed
Runs on your computer with your user’s permissions (files, network, apps).
The registry lists no key to fill in.

You need

PyPIPython’s uv installed (for the uvx command)

Which app do you use?

ClaudeClaude CodeCursorVS CodeChatGPT

Pick your app above. We remember it, so next time the button says “Install in …”.

Open Claude Desktop → Settings → Developer → Edit Config, and paste this into claude_desktop_config.json

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

Run this in your terminal

claude mcp add diffctx -- uvx diffctx

Open in Cursor

Or copy the settings yourself

Paste into .cursor/mcp.json in your project, or ~/.cursor/mcp.json

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

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

Open in VS Code

Or copy the settings yourself

Paste into .vscode/mcp.json in your project

{
  "servers": {
    "diffctx": {
      "type": "stdio",
      "command": "uvx",
      "args": [
        "diffctx"
      ]
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

This one runs on your computer, and ChatGPT can only connect to servers on the internet. Pick another app.

Your choice stays on this device in a cookie; no account needed.

These settings are generated from the maker’s registry entry. If the README says otherwise, follow the README.

What it can do

Runs on your computer; the tool list appears in your AI app after you install it.

Basic checksi

We check information anyone can see; we have not read the code. Checks that do not apply are left out of the count. · Checked Nov 6, 2026

✓ Pass
Maker matches the repo
The registry name was verified with the GitHub account nikolay-e, which owns the repo
… Not checked yet
Still maintained
We have not read this repo from GitHub yet
… Not checked yet
Has a licence
We have not read this repo from GitHub yet
– Not applicable
Endpoint responds
This one runs on your computer; there is no internet endpoint
– Not applicable
Sign-in with OAuth
Runs on your computer and uses local settings instead
… Not checked yet
No hidden instructions in tool descriptions
Runs on your computer; we can only read tool lists from internet endpoints

Compared with others in Search & AI memoryi

More stars than 0% of the other 7233 servers in this category
Published to the registry more recently than 72% of the other 7233 servers in this category
Basic checks equal to or better than 100% of the other 7233 servers in this category

Compared with every active server in this category in the registry. Stars count only when the publisher owns the repo.

Common questions

Is diffctx safe?

It passed 1 of 1 applicable basic checks. We have not read the code. Before adding a key or token, see what access the server asks for and use a key with only the permissions you need.

What keys or codes does it need?

The registry does not list a required key, though some servers ask you to sign in on first use.

Does it run on my computer or in the cloud?

It runs on your computer. Your AI app starts it when needed, and data does not pass through the maker’s servers (unless it calls an online service itself).

Is it still maintained?

The GitHub repo last changed –, and the latest version (1.20.0) reached the registry 15 days ago.

Which apps can use it?

Apps that support MCP, such as Claude Desktop, Claude Code, Cursor and VS Code. You also need Python (uv) on your computer.

What can I use instead?

In the same category: Context7, Codebase Memory, Exa

Alternatives

Servers in the same category from other makers, sorted by stars.

Reading a card:★ GitHub starsiThree pillars: reviews · checks · usageiUpdated = latest version published to the registryi

Context7

by upstash

Feeds AI the latest docs for libraries and frameworks before it answers, so code it writes does not use outdated, removed functions.

Computer or cloud★ 64,224MITUpdated 3 days ago

Install

Codebase Memory

by DeusData

Codebase knowledge graph for AI agents — 162 languages, sub-ms queries, 99% fewer tokens.

Runs on your computer★ 48,148MITUpdated 20 days ago

Install

Exa

by exa-labs

Connect AI agents to Exa for web search, content fetching, and multi-step research.

Runs in the cloud★ 5,213MITUpdated 44 days ago

Install

README from the maker

Open the README

Copied from the maker’s repo as written. PopNx MCP has not reviewed or endorsed it. HTML, images and scripts are removed. Links lead off this site.

diffctx — what a git change reaches, and the code to review it

diffctx tells an agent or a reviewer what a change reaches outside its diff — the callers, the tests that reach them, the contracts it crosses — and selects the code needed to understand it under a token budget. Local, deterministic, no index, no model calls. Caller resolution is static and per language; where it cannot resolve, the answer says so instead of printing a zero.

Formerly published as treemapper — every command, flag, and API call works unchanged.

Install

diffctx is a command-line tool; the MCP server, the Claude Code plugin and the GitHub Action run the same engine.

CLI

uvx diffctx . --diff HEAD~1             # zero-install, run once via uv

pipx install diffctx # isolated CLI pip install diffctx # into an active environment cargo install diffctx # native binary from crates.io, no Python npx diffctx . --diff HEAD~1 # npm wrapper over the native binary docker run --rm -v "$PWD:/repo" ghcr.io/nikolay-e/diffctx . --diff HEAD~1

scoop bucket add diffctx https://github.com/nikolay-e/diffctx   # Windows

scoop install diffctx/diffctx

The native binary — cargo, npm, Docker, Scoop and the release archives for Linux, macOS and Windows on x64 and ARM — answers --diff and --symbol in every mode; whole-tree export, Markdown packs, diffctx graph and the MCP server need the Python package.

Any MCP client

Registered as io.github.nikolay-e/diffctx.

claude mcp add diffctx -- uvx --from 'diffctx[mcp]' diffctx-mcp

codex mcp add diffctx -- uvx --from 'diffctx[mcp]' diffctx-mcp gemini mcp add diffctx uvx -- --from 'diffctx[mcp]' diffctx-mcp

Cursor, VS Code, Claude Desktop, Windsurf, Zed, Continue and the Python API: integrations.

Claude Code plugin

The MCP server plus /diffctx:impact and hooks that run it on each commit and push.

claude plugin marketplace add nikolay-e/diffctx

claude plugin install diffctx@diffctx

CI

The GitHub Action hands a pull request's diff context to any review step.

Usage

diffctx . --diff --mode impact          # uncommitted work: callers outside the diff, their tests, contracts

diffctx . --symbol parse_config # the same for a name, no change needed diffctx . --diff main...feature # the code to review a branch, packed under the auto budget diffctx . --diff HEAD~1 --budget 12000 # the last commit, capped at 12k o200k tokens diffctx . --diff 24h --mode locate # today's work as ranked JSON, no source bodies diffctx . # whole-tree export, Markdown

--diff takes a git range, staged, or a duration window ending now (24h, 90min, 2w). Every flag, default and exit code: command-line reference.

How it compares

Whole-repo packers export everything; code-graph servers answer queries against a maintained index. diffctx is diff-seeded: the input is a change, the output is what it touches and what explains it. Measured results, and when the other two fit better: COMPARISON.md.

Documentation site — the pipeline end to end
Command-line reference — rendered from diffctx --help
Integrations — install, MCP clients, Python API
FAQ — heuristic or oracle, ignore rules, monorepos, secrets
Token counting — --budget for non-GPT models
Benchmarks and the paper
Changelog · Security
Parameter strategy

Apache 2.0

diffctx

Overview

PopNx MCP’s three pillars

What you can do with it

Install

Before you install

What it can do

Basic checksi

Maker matches the repo

Still maintained

Has a licence

Endpoint responds

Sign-in with OAuth

No hidden instructions in tool descriptions

Compared with others in Search & AI memoryi

Common questions

Alternatives

Context7

Codebase Memory

Exa

README from the maker

diffctx — what a git change reaches, and the code to review it

Install

CLI

Any MCP client

Claude Code plugin

CI

Usage

How it compares

More