--- title: "Run CI once per pull request commit" description: "Remove overlapping push and pull request triggers so each change receives one intended validation run." url: https://starsling.dev/ci-playbooks/techniques/run-ci-once canonicalUrl: https://starsling.dev/ci-playbooks/techniques/run-ci-once --- # Run CI once per pull request commit Remove overlapping push and pull request triggers so each change receives one intended validation run. ## How to choose an approach Compare the examples by repository setup, prerequisites, and risks before adopting one. Each company implemented this in its own environment; measure each change against your own baseline. - **[Anthropic](https://starsling.dev/ci-playbooks/anthropic#one-run-per-change)**: Use it when Run history shows duplicate events for the same commit, or metadata events rerun checks that do not depend on that metadata. Check before adopting: Preview deployments, cache warming, release side effects and metadata-dependent checks keep the triggers they need. - **[Shopify](https://starsling.dev/ci-playbooks/shopify#run-commit-once)**: Use it when The same commit runs equivalent validation through both push and pull_request, and developers push several times in a row. Check before adopting: Check that the two runs test the same ref with the same permissions before treating them as duplicates. - **[Spotify](https://starsling.dev/ci-playbooks/spotify#push-main-only)**: Use it when A workflow triggers on both push and pull_request, and the push trigger covers every branch. Check before adopting: Branches without a pull request no longer get push builds; the workflow keeps workflow_dispatch for running them by hand. ## Apply this technique ````text Evaluate and apply this CI technique to my repository: Run CI once per pull request commit. Remove overlapping push and pull request triggers so each change receives one intended validation run. Read the technique and its source-backed company examples: https://starsling.dev/ci-playbooks/techniques/run-ci-once.md Inspect this repository’s CI workflows, build and test commands, dependencies, and recent run timings. Identify where this technique applies and explain the expected benefit using this repository’s evidence. Measure a baseline from recent comparable runs: elapsed time, queue time, runner minutes and failures where available. If data is unavailable, say what cannot be measured. Compare relevant company approaches, checking prerequisites, platform differences and tradeoffs. Rank applicable options by evidence, fit and measurable opportunity; do not present company results as predictions for this repo. Recommend the smallest safe change, show what checks and fallback paths remain, and ASK ME WHICH CHANGE TO APPROVE BEFORE EDITING ANY FILES. Only after approval, work on a new feature branch, make one reversible change, and open a reviewable pull request. Never merge or push to a default or protected branch. Keep required checks, test coverage, deployment and release behavior intact. Validate the change and compare equivalent runs where possible; report limitations and what should be monitored after merge. ```` ## How companies used this technique Read what each company changed and follow the original sources. ### Anthropic: Run CI once per change Anthropic reports more CI jobs in a given day. As a StarSling pattern for GitHub Actions, removing duplicate push and pull_request runs and metadata-only triggers keeps each change to one run. Evidence: StarSling pattern for GitHub Actions Use it when: Run history shows duplicate events for the same commit, or metadata events rerun checks that do not depend on that metadata. Before applying it: Preview deployments, cache warming, release side effects and metadata-dependent checks keep the triggers they need. [Read more in the Anthropic playbook](https://starsling.dev/ci-playbooks/anthropic#one-run-per-change) [Primary source](https://claude.com/resources/articles/agentic-coding-is-straining-ci-heres-how-we-scaled-test-impact-analysis-at-anthropic) ### Shopify: Run each pull-request commit once The Ruby extension's workflow ran on every push and every pull request, so each in-repo branch got two identical runs; for one commit they started three seconds apart. Shopify/vscode-shopify-ruby#808 limits push to main and adds a concurrency group whose cancellation applies only to pull_request events, so a main run that is already running is never cancelled, though a main run still waiting in the same group is replaced by a newer push. Evidence: Source PR/commit evidence Merged 2026-09-18; the workflow on the default branch is unchanged since. ([Source](https://github.com/Shopify/vscode-shopify-ruby/pull/808)) Use it when: The same commit runs equivalent validation through both push and pull_request, and developers push several times in a row. Before applying it: Check that the two runs test the same ref with the same permissions before treating them as duplicates. [Read more in the Shopify playbook](https://starsling.dev/ci-playbooks/shopify#run-commit-once) [Primary source](https://github.com/Shopify/vscode-shopify-ruby/pull/808) ### Spotify: Run push builds only on the default branch target-determinator's presubmit workflow ran on every push and on every pull request, so a commit pushed to a pull request branch in the repository ran the test matrix twice. The change restricts the push trigger to main; pull requests still run through the pull_request event. Evidence: Source PR/commit evidence Use it when: A workflow triggers on both push and pull_request, and the push trigger covers every branch. Before applying it: Branches without a pull request no longer get push builds; the workflow keeps workflow_dispatch for running them by hand. [Read more in the Spotify playbook](https://starsling.dev/ci-playbooks/spotify#push-main-only) [Primary source](https://github.com/spotify/target-determinator/pull/15) ## CI optimization is continuous work. Apply this technique yourself, or use StarSling Runners for faster GitHub Actions and optional agent-driven optimization PRs, which teams on eligible paid plans can turn on. [Get self-improving CI](https://starsling.dev/products/runners) ## Related techniques ### [Cancel superseded pull request runs](https://starsling.dev/ci-playbooks/techniques/cancel-superseded-runs) Free runner capacity by canceling validation that a newer commit has replaced. Keep required main-branch and release runs intact. 4 implementations · 4 companies (Anthropic, Mastra, Stripe, Uber) ### [Reject irrelevant events before allocating runners](https://starsling.dev/ci-playbooks/techniques/gate-irrelevant-events) Put event and change conditions before runner allocation so irrelevant comments or edits do not start expensive jobs. 3 implementations · 2 companies (Mastra, OpenAI) ### [Package once, and build full installers after merge](https://starsling.dev/ci-playbooks/techniques/package-once) Drop the build step that packaging repeats, and build the unpacked app pull requests test. 1 implementation · 1 company (DoorDash) ## Company Playbooks ### [Anthropic](https://starsling.dev/ci-playbooks/anthropic) Run only affected tests ### [DoorDash](https://starsling.dev/ci-playbooks/doordash) Run build and test in parallel, sharded across CI agents ### [Linear](https://starsling.dev/ci-playbooks/linear) Benchmark the same job on faster hardware ### [Mastra](https://starsling.dev/ci-playbooks/mastra) StarSling runners for the slowest test workflow ### [OpenAI](https://starsling.dev/ci-playbooks/openai) Rank CI fixes by the minutes they save ### [Ramp](https://starsling.dev/ci-playbooks/ramp) Move a CPU-bound test suite to a faster CPU ### [Shopify](https://starsling.dev/ci-playbooks/shopify) Let an agent iterate against one CI metric ### [Spotify](https://starsling.dev/ci-playbooks/spotify) Build arm64 on native arm64 runners ### [Stripe](https://starsling.dev/ci-playbooks/stripe) Run only the tests a change can reach ### [Uber](https://starsling.dev/ci-playbooks/uber) Build the merge-queue speculations most likely to be needed ## Related guides Implementation guides for this technique. ### [Cancel superseded CI runs](https://starsling.dev/best-practices/github-actions/cancel-superseded-runs) Use concurrency groups to keep PR verification focused on the latest commit. ### [Build and test only what changed](https://starsling.dev/best-practices/github-actions/build-only-affected) Scope work with your dependency graph and keep a full-run fallback. ### [Cut CI queue time](https://starsling.dev/best-practices/github-actions/cut-queue-time) Measure waiting time and identify concurrency or capacity constraints. ### [Filter workflows by changed files](https://starsling.dev/best-practices/github-actions/path-filter-workflows) Use paths and job conditions while keeping required checks reporting. ### [Bound runner jobs with timeouts](https://starsling.dev/best-practices/github-actions/bound-job-timeouts) Set job and step timeouts using expected durations and failure behavior. ### [Right-size GitHub Actions runners](https://starsling.dev/best-practices/github-actions/right-size-runners) Match runner resources to the workload and compare equivalent runs.