Stop Writing MR/PR Descriptions Manually — Let AI Do It From Your Git Diff

Solehudin — Fri, 05 Jun 2026 16:04:10 +0000

The problem I kept ignoring

Every time I opened a merge request, there was this familiar moment of dread. I had just spent hours writing code, and now I had to sit down and summarize it all in a description box. What changed? Why? What should reviewers look at?

Most of the time I'd write something like "fix login bug" and call it a day. My teammates did the same. Reviews were slow because nobody knew what to focus on.

The irony? The git diff already had everything. The AI just needed to read it.

Introducing mergist

mergist is a CLI tool that reads your git diff and generates a structured MR/PR description using AI — automatically in CI, or on-demand from your terminal or browser.

One command to get started: npx mergist init

How it works

There are two ways to use it:

1. CI mode (recommended for teams)

mergist hooks into your CI pipeline and generates a description every time a MR/PR is opened or a new commit is pushed.

For GitLab:

mergist:
  stage: mergist
  image: node:20-alpine
  rules:
    - if: $CI_PIPELINE_SOURCE == "merge_request_event"
  script:
    - npx mergist generate -p gitlab
  allow_failure: true

For GitHub Actions, npx mergist init generates the workflow file automatically.

2. Manual mode

# Compare two branches and generate description
npx mergist diff -f feature-branch -t main

# Or update an existing MR/PR
npx mergist diff -u https://gitlab.com/org/repo/-/merge_requests/42

# Launch browser UI
npx mergist ui

What the generated description looks like

You can choose which sections to include during init:

Section	Filled by	Description
Summary	AI	Brief overview of what changed and why
Changes	AI	Bulleted list with Add / Change / Remove prefixes
Review notes	AI	Code analysis: risk / warn / suggestion / good
Testing checklist	AI	What to verify before merging
Notes	Human	Left blank — never overwritten by AI
References	Human	Issue/ticket links — also preserved

Smart merge — human notes stay untouched

One thing I'm proud of: the autoUpdate feature. When enabled, mergist re-runs on every new commit — but it only rewrites the AI-generated sections. Your manually filled notes and references are never touched. This was critical for team adoption.

Multi-provider support

You're not locked into one AI provider. During setup you can choose:

OpenAI — GPT-4o, etc.
Anthropic — Claude
DeepSeek — very cost-effective
Groq — fast inference
Custom — any OpenAI-compatible endpoint

Just set AI_API_KEY in your environment — no code changes needed to switch providers.

Platform support

GitLab — gitlab.com and self-hosted instances
GitHub — github.com via GitHub Actions

Output language is also configurable: English (en) or Indonesian (id) via .mergistrc.

Try it out

npx mergist init

It'll walk you through selecting a platform, AI provider, CI config, and which sections to include. Takes about 2 minutes.

GitHub: https://github.com/solehudin5699/mergist
npm: https://www.npmjs.com/package/mergist

I'd love to hear how it fits into your workflow — especially if you're using self-hosted GitLab or a custom AI endpoint. Drop a comment or open an issue!

AI Disclosure

This article was drafted with the assistance of AI and subsequently reviewed, edited, and refined by the author. All technical content, code examples, and implementation details were validated before publication.

DEV Community: Solehudin