AI writes 2,000 lines in one shot.
Stack them.
Stacks turns every commit on your branch into its own pull request. One local branch with standard Git, each commit its own focused PR. Reviewers see small diffs. Your merge queue handles the rest.
Code review, unblocked.
PR #421 ← refactor: extract auth middleware ✓ created PR #422 ← feat: add OAuth2 provider support ✓ created PR #423 ← feat: add token refresh logic ✓ created PR #424 ← test: add auth integration tests ✓ created
Used by platform teams at
From fast-moving startups to well-known enterprises
"Mergify gave us a merge queue that behaves predictably under heavy load. Reliability is everything, and Mergify made stability a solved problem."
Rushin Shah, Sr. Manager DevInfra
"The merge queue is a huge value from Mergify: it keeps our main stable and allows us to merge quickly with confidence."
Minh Tran, Platform Engineer
"You get the benefits of Mergify immediately. There is no competitor doing stuff like this."
Florian Berchtold, Software Engineer
"Since adopting Mergify, our code quality has skyrocketed. We've drastically reduced post-deployment bugs."
Bálint Bartha, Senior Platform Engineer
"We transitioned from manual chaos to over 20 safe deploys per day. Mergify is becoming a critical part of our delivery function."
Chris Irving, Engineering Manager
"We basically turned GitHub into an autonomous system. Mergify runs the entire choreography for us."
Fabien Marty, Senior Staff Software Engineer
"With dozens of engineers and long-running CI jobs, Mergify turned what used to be a daily bottleneck into a background process. Our teams focus on hardware, not merge logistics."
Ben Holtzman, Senior Design Enablement Engineer
"Before Mergify, we spent too much time manually coordinating merges. Now everything flows automatically."
Nicolas Beaussart-Hatchuel, Senior Staff Software Engineer
"Mergify was the best fit. It saved a couple of hours per engineer per month and resolved our bottleneck with the merge queue."
Tomas Nekolny, Engineering Manager
"The support on Slack is really good, reactive and transparent. We have other partners where problems feel less transparent. With Mergify, it's fluid."
Clément Danjou, VP Blockchain
The 2,000-line PR that nobody actually reviews
An AI agent refactors your authentication layer in 40 minutes. It touches 47 files and produces a single pull request with 2,100 lines changed. Two reviewers approve it within an hour. Neither read past the first 300 lines.
This is the new normal. AI coding tools generate complete, working changesets at a pace that makes large PRs inevitable. The code is often correct. The reviews are almost never thorough. When something breaks in production, nobody can point to which change caused it because the diff was a wall of text that got a rubber-stamp approval.
The problem is structural. You can't review what you can't hold in your head.
Problems that multiply with every AI-generated changeset
The bigger your PRs get, the worse each of these becomes.
Reviews become theater
Review quality drops sharply after 400 lines. A 2,000-line PR gets surface-level skimming and a polite "LGTM." Bugs hide in the parts nobody read.
Rollbacks take the whole feature
When one change in a monolithic PR causes a production issue, you revert everything. The 90% of changes that were fine get rolled back too.
Review bottlenecks multiply
Large PRs sit in review queues for days because nobody has 2 hours to read them. Smaller PRs get reviewed in minutes. The throughput difference compounds across a team.
Context is impossible to transfer
When an AI agent writes code across 47 files, the reviewer reconstructs the agent's reasoning from the diff alone. Stacking gives each PR a clear, single purpose.
We went from PRs sitting in review for days to getting them merged the same afternoon. Stacking forced us to write smaller, clearer commits. Reviewers stopped procrastinating because each PR was a 10-minute read, not a 2-hour slog.
Marie Laurent
Senior Software Engineer at SG
One prompt. Your agent does the rest.
No GitHub App to authorize. No dashboard to log into. No OAuth flow. Paste this into your AI agent and it installs the CLI, the skill, and the Git hooks for this repo.
Works with Claude Code · Cline · Codex · Copilot · Cursor · any skill-compatible agent
Same code, same branch, four reviewable PRs
Stacks maps each commit on your branch to its own pull request. You keep working in a single local branch with standard Git. Mergify handles the PR chain and keeps everything in sync. Reviewers see 200-line diffs, not 2,000-line walls.
One branch, many PRs
Each commit becomes a separate PR with its own reviewers, CI run, and approval status. Your local workflow stays a single branch with standard Git commands.
Automatic dependency chain
Stacks sets the base branch of each PR to the previous PR in the chain. GitHub shows only that PR's diff, not the cumulative change. Reviewers see exactly what changed in that commit.
Two new commands. The daily workflow.
Install is a one-time prompt to your agent. After that, stacks lives in your terminal with the Git commands you already know.
PR #421 ← refactor: extract auth middleware ✓ PR #422 ← feat: add OAuth2 provider support ✓ PR #423 ← feat: add token refresh logic ✓
Smart updates
Amend a commit and push again. Only the PR for that commit gets updated. The others keep their reviews and CI status intact.
Merge queue integration
When the first PR in the chain is approved, it enters the merge queue. After it merges, the next PR automatically becomes merge-ready.
Review in GitHub directly
No external app, no extra dashboard. Stacked PRs are regular GitHub pull requests. Your reviewers use the tools they already know.
See the stack inside GitHub.
Stacks work in GitHub without anything extra. A free browser extension is also available, adding a richer view of the chain and revision history inside the PR page itself.
Stack at a glance
Every PR in the stack appears on the PR page you opened, with its status and your position in the chain.
Revision history
A timeline of every revision, with commit SHAs. Click any one to see what changed between reviews.
No second tool to merge
Reviews and merges go through GitHub and your queue. The extension only adds context, so your stack works the same way whether you install it or not.
Already drowning in AI-generated PRs?
See how Stacks breaks them into reviewable pieces. Free, open-source CLI. No dashboard, no external app. Just Git and GitHub.
Built for the age of AI-generated code
AI coding agents don't think in small PRs. They think in complete features. Stacks is the missing layer between AI output and human review.
Change-Id persistence
Every commit gets a unique Change-Id that survives rebases and amends. When you push again, Stacks matches commits to their existing PRs. No duplicate PRs. No lost review context.
Skip what didn't change
When you amend commit #2 in a 5-commit stack and push, only PR #2 gets updated. PRs #1, #3, #4, and #5 keep their approvals and CI status. Reviewers re-review only what actually changed.
Our AI coding agent kept producing 1,500-line PRs. Nobody wanted to review them, so they sat open for a week. Stacks turned those into four or five focused PRs that went through review in a day. It changed how our whole team works with AI-generated code.
Erik Johansson
Platform Engineer at Wavefront
Coming from another stacking tool?
See how Stacks compares to gh-stack and other tools. Honest comparison, no spin.
Real teams, real results
Engineering teams we helped merge faster, safer, and cheaper
Stop shipping 2,000-line PRs
Stacks turns commits into reviewable PRs. Free CLI, no sign-up required.