When you need a collision signal before the queue.

Why this is hard for a small team

A merge queue’s value is highest when (a) you have enough parallel merges that the queueing delay is amortised against the breakage you avoid, and (b) you have a strong CI suite that reliably catches cross-PR interference when the next-in-line PR re-tests. Both are true at scale. At small-team scale, the queueing delay can outweigh the breakage rate, and CI may not carry enough surface coverage to catch likely overlap before a rebase looks clean.

Some teams need a queue. Others first need a clearer collision signal: before merge, while the work is still cheap to reorder, rebase, or review. An optional acknowledgement can record an override when a team wants an audit trail.

What kind of tool helps

Two categories sit next to each other here. A merge queue (GitHub Merge Queue, Mergify, Aviator, Graphite’s merge queue) serialises merges, re-tests each PR against the next-in-line tree, and enforces a green-main invariant by sequencing. A pre-merge collision check sits before that step: it tells you when open PRs may overlap, so you (or your queue) can decide land order with more context.

A queue without a collision check still ships sequentially, but it pays the queueing delay on every merge. A collision check without a queue lets you ship as fast as you can, but trusts the team to act on the warning. Some workflows use just the check; others run both.

How Veripsa Core does it

Veripsa Core is a GitHub App that posts an advisory check on covered PRs. The check reports one of four states — Clear, Heads up, Wait in line, Unknown — based on whether likely overlap is observed with another open PR on the same repo. When likely overlap is observed on covered PRs, affected PRs get an advisory signal; a suggested land order appears when useful. You (or your merge queue, if you have one) decide what merges.

Veripsa Core is not a merge queue. It does not serialise your merges, does not hold PRs for you, and does not require you to set a required check on your protected branches to be useful. If you already run a merge queue, Veripsa Core can sit upstream of it — the queue still serialises, and the check gives reviewers context about overlap before the queue runs.

• Not a merge queue. Advisory check, no queueing delay, no required-check precondition.
• Pairs with a queue. If you already run GitHub Merge Queue, Mergify, Aviator, or Graphite, Veripsa Core runs upstream of it. See the combination guide.
• Content-free. Veripsa Core uses minimal operational metadata for advisory checks. File bodies are not stored.
• Free early-access band. Install the GitHub App and stay inside fair-use limits. Future paid plans are expected through GitHub Marketplace; current plan details live on pricing without a checkout step.