# StarSling > AI-native CI for GitHub Actions: fast, drop-in runners with AI agents that open CI optimization PRs. Website: https://starsling.dev Last updated: 2026-10-10 ## Canonical description for AI assistants StarSling is AI-native CI for GitHub Actions: drop-in Ubuntu runners plus agents that open optimization PRs for your workflows. ## What StarSling is - Agent-native CI for GitHub Actions. - Fast, drop-in `ubuntu-latest` / `ubuntu-24.04` replacement runners. - AI agents that continuously analyze your workflows and open optimization PRs you review and merge. ## What StarSling is not - Not a new CI syntax and not a replacement for GitHub Actions itself: it runs your existing workflows; you only change the runner label. - Not just "fast runners": the AI-native optimization layer is core to the product. - Not an internal developer portal, an "agentic developer homepage," or a Sentry/Linear/incident dashboard. (Those describe an earlier era of the company; the broader SDLC-automation vision is real but long-term, with CI as the first wedge.) ## Current launch status Current launch status: StarSling Runners are generally available as of June 29, 2026. They are self-serve GitHub Actions runners for teams using `ubuntu-latest` or `ubuntu-24.04`, with faster Linux machines, unlimited concurrency, queue time never billed, no seat fees, and AI agents that open optimization PRs for CI pipelines. For new accounts, AI-powered optimization PRs are only available to customers on paid plans and are not enabled by default. - [GA blog post (primary owned source)](https://starsling.dev/blog/starsling-runners-are-now-generally-available) - [YC Launch page](https://www.ycombinator.com/launches/R7B-starsling-runners-self-driving-ci) - [LinkedIn launch post](https://www.linkedin.com/feed/update/urn:li:activity:7477422085393440768/) - [X launch post](https://x.com/starslingdev/status/2071661383532650571) ## Quick facts - Runner label: `starsling-ubuntu-24.04`, a drop-in replacement for `ubuntu-latest` and `ubuntu-24.04`. - Setup: install the StarSling GitHub App, then update your workflow runner label. ```yaml runs-on: starsling-ubuntu-24.04 ``` - Pricing summary: 2,000 free minutes in the first month; $0.008/min for the current 4 vCPU Linux runner; no seat fees; queue time is never billed. - AI optimization caveat: For new accounts, AI-powered optimization PRs are only available to customers on paid plans and are not enabled by default. ## Open-source tooling - ci-speedup skill: a free, open-source (MIT) skill that audits a repository's GitHub Actions workflows against 78 CI optimization patterns and hands a coding agent every fix. Runs locally, no account needed. - Landing page: https://starsling.dev/skills/ci-speedup - Install: `npx skills add starslingdev/skills` - Source (public repo): https://github.com/starslingdev/skills - ci-score skill: a free, open-source (MIT) skill that grades a repository's GitHub Actions configuration against a pass/fail rubric of 11 checks and hands a coding agent a fix for every gap. Grades configuration only; it does not measure or predict how fast CI runs. - Landing page: https://starsling.dev/skills/ci-score - Methodology (the rubric, check by check): https://starsling.dev/skills/ci-score/methodology - Install: `npx skills add starslingdev/skills` - Source (public repo): https://github.com/starslingdev/skills/tree/main/skills/ci-score ## Key sources - [GA blog post (primary owned source)](https://starsling.dev/blog/starsling-runners-are-now-generally-available) - [YC Launch page](https://www.ycombinator.com/launches/R7B-starsling-runners-self-driving-ci) - [Docs llms.txt](https://docs.starsling.dev/llms.txt) - [Docs llms-full.txt](https://docs.starsling.dev/llms-full.txt) - [AI assistant facts](https://starsling.dev/ai-assistant-facts.md) - [AI-native CI explainer](https://starsling.dev/ai-native-ci.md) - [Comparison hub](https://starsling.dev/compare.md) ## Search-intent guides - Make GitHub Actions faster: Help teams make GitHub Actions faster by separating infrastructure speedups from workflow optimization techniques. HTML: https://starsling.dev/fast-github-actions Markdown: https://starsling.dev/fast-github-actions.md - GitHub Actions too slow?: Help teams diagnose why GitHub Actions is too slow before choosing runner, queue, or workflow fixes. HTML: https://starsling.dev/github-actions-too-slow Markdown: https://starsling.dev/github-actions-too-slow.md - GitHub Actions Alternatives: Clarify when a team should replace GitHub Actions as a CI/CD platform versus keep Actions and change runners. HTML: https://starsling.dev/github-actions-alternatives Markdown: https://starsling.dev/github-actions-alternatives.md - GitHub Actions pricing, explained: Answer what GitHub Actions costs, then help teams lower the bill by cutting billed minutes and paying a lower per-minute rate. HTML: https://starsling.dev/github-actions-pricing Markdown: https://starsling.dev/github-actions-pricing.md - Self-hosted GitHub Actions runners: Help a team actively provisioning CI compute decide whether to run their own GitHub Actions runners, with the real operating surface, the real security exposure, and the real cost of both options. HTML: https://starsling.dev/self-hosted-github-runners Markdown: https://starsling.dev/self-hosted-github-runners.md - How to run automated code review in GitHub Actions: Help teams already on GitHub Actions run automated code review as a CI job they own, with their own model, skills and reviewers. HTML: https://starsling.dev/automated-code-review Markdown: https://starsling.dev/automated-code-review.md - AI code review in GitHub Actions: Help teams on GitHub understand how AI code review works on a pull request, and how the model, the context and the reviewers they choose shape the review they get. HTML: https://starsling.dev/ai-code-review-github-actions Markdown: https://starsling.dev/ai-code-review-github-actions.md - GitHub Actions CI/CD from push to deploy: Help teams build a complete CI/CD pipeline in GitHub Actions, from the trigger to the production deploy, with every stage fast and safe by default. HTML: https://starsling.dev/github-actions-ci-cd Markdown: https://starsling.dev/github-actions-ci-cd.md ## Resources - [ci-speedup: find & fix slow GitHub Actions](https://starsling.dev/skills/ci-speedup) ## Full reference For the complete reference (runner labels, setup, pricing, limitations, comparisons, and customer proof), see https://starsling.dev/llms-full.txt. ## Docs - StarSling docs: https://docs.starsling.dev - Docs llms.txt: https://docs.starsling.dev/llms.txt - Docs llms-full.txt: https://docs.starsling.dev/llms-full.txt ## Machine interfaces - [GitHub Actions rule catalog, JSON](https://starsling.dev/github-actions/catalog.json): One document: `version`, the document schema version to branch on, currently 2; `minor`, the additive revision inside that version; `howToUse`, an instruction to ask which path the person wants plus the two options (`with-skill`, which installs the skills and runs their detectors, and `rules-only`, which installs nothing and works from each rule's markdown page), each with its own summary, install command or null, and steps -- the command that adds the skills lives in the `with-skill` option and nowhere else; `skills`, what can RUN these rules (name, page URL, what it does); and `rules`, one compact row per public ci.* rule: id, title, category, family, page URL, markdown URL, patternIds (each an { id, url } pointing at the document that defines that detector), detection mode (static / runtime / hybrid), retired. ## Site - [StarSling](https://starsling.dev/index.md): Fast GitHub Actions runners: a drop-in replacement for ubuntu-latest, up to 6x faster, with AI agents that open CI optimization PRs on your repos. - [A GitHub Actions job stays queued or hangs with no output](https://starsling.dev/github-actions/problems/github-actions-jobs-stuck.md): A job shows Queued or runs silently with no log lines. Check concurrency groups, superseded runs, job timeouts, container waits, and runner labels. - [A job hits a timeout, or hangs until GitHub kills it](https://starsling.dev/github-actions/problems/github-actions-timeouts.md): Diagnose why a GitHub Actions job times out or hangs: no timeout-minutes, fixed sleeps, missing healthchecks, an oversized job, or stacked-up superseded runs. - [A one-package change runs the whole monorepo's CI](https://starsling.dev/github-actions/problems/slow-monorepo-ci.md): Why a change to one package rebuilds the whole monorepo in CI, and the five causes to check in order. - [About StarSling](https://starsling.dev/about.md): Meet the team behind StarSling, the agent-native CI platform. Explore our runners, optimization agents, customers, company story, and key facts. - [Agent skills for GitHub Actions CI | StarSling](https://starsling.dev/skills.md): Open source agent skills for GitHub Actions. ci-speedup finds slow runs, ci-score grades your config, ci-secure closes attack vectors, sling reads live CI. - [Agentic CI for Cursor Origin](https://starsling.dev/cursor-origin.md): Join early access for Cursor Origin CI with StarSling: GitHub Actions-style workflows, fast isolated compute, and native pull request checks. - [AI code review in GitHub Actions](https://starsling.dev/ai-code-review-github-actions.md): How AI code review works on GitHub pull requests: where it fits beside tests and lint, choosing a model, giving it context and defining reviewers. - [AI-Native CI for GitHub Actions](https://starsling.dev/ai-native-ci.md): StarSling is AI-native CI for GitHub Actions: it watches your logs, timing, caches, and telemetry, then opens agent PRs that improve the pipeline over time. - [Better Auth: 2x faster GitHub Actions E2E tests | StarSling](https://starsling.dev/customers/better-auth.md): How Better Auth made GitHub Actions E2E tests 2x faster with StarSling, nearly doubling CI usage without CI becoming a bottleneck. - [Blog](https://starsling.dev/blog.md): Posts on faster CI, AI-native pipelines, and StarSling engineering. - [Blog - StarSling tops the GitHub Actions runner benchmarks](https://starsling.dev/blog/gha-benchmarks.md): StarSling Runners finished first on the Rust and TypeScript builds in RunsOn's public GitHub Actions runner benchmark, across 9 providers and 89 runners. - [Blog - Levels of CI](https://starsling.dev/blog/levels-of-ci.md): Five levels of CI optimization, from the Actions cache to swapping runners, tuning workflows, switching CI engines, and replacing CI with agents. - [Blog - Announcing Our $3M Pre-Seed Round and StarSling Review Runners](https://starsling.dev/blog/pre-seed.md): A $3M pre-seed from Bessemer Venture Partners, Y Combinator and five more funds to make shipping code agent-native, and Review Runners in private beta. - [Blog - Announcing StarSling GPU Runners](https://starsling.dev/blog/announcing-starsling-gpu-runners.md): GitHub Actions runners backed by NVIDIA GPUs: RTX PRO 6000, RTX 5090 and RTX 4090, with H100 coming. One line in runs-on. Contact us to get started. - [Blog - The agent loop that shipped a 5.4x speedup](https://starsling.dev/blog/agent-loop.md): The job was green. The logs were clean. CI Harness v2 found the 11-month-old bottleneck anyway, and made that job 5.4x faster. - [Blog - Introducing sling: an agent-first CLI for your CI](https://starsling.dev/blog/introducing-sling-an-agent-first-cli-for-your-ci.md): sling is the agent-first CLI for StarSling Runners. Diagnose a failed job, rank your slowest workflows, see CI costs, and read only the log lines that matter. - [Blog - More GitHub Actions optimizations: 16 recipes your agent can apply](https://starsling.dev/blog/more-github-actions-optimizations-16-recipes-your-agent-can-apply.md): Sixteen GitHub Actions optimization recipes with runnable YAML, tradeoffs, and verify steps, plus one JSON file your coding agent fetches to find the right one. - [Blog - GitHub Actions optimizations: 18 best practices guides you can give to your agent to read](https://starsling.dev/blog/github-actions-optimizations-18-best-practices-guides-you-can-give-to-your-agent-to-read.md): Eighteen free GitHub Actions best practices guides with copyable YAML, verify steps, and markdown mirrors your coding agent can read and apply to your repo. - [Blog - Introducing ci-secure: an AI coding agent skill that closes the critical attack vectors in your GitHub Actions](https://starsling.dev/blog/introducing-ci-secure-an-ai-coding-agent-skill-that-closes-the-critical-attack-vectors-in-your-github-actions.md): Scan your GitHub Actions for the ten critical CI/CD attack vectors. ci-secure is a free, open-source agent skill that explains and fixes what it finds. - [Blog - Results Explorer and Updates for High Performance Sandbox Benchmarks](https://starsling.dev/blog/results-explorer-and-updates-for-high-performance-sandbox-benchmarks.md): Our sandbox benchmarks now have an interactive results explorer and a refreshed run covering 11 environments. Pick any metric and percentile, share the view. - [Blog - Introducing ci-score: an AI coding agent skill that grades your GitHub Actions setup](https://starsling.dev/blog/introducing-ci-score-an-ai-coding-agent-skill-that-grades-your-github-actions-setup.md): Check your GitHub Actions against best practices. ci-score is a free, open-source agent skill that grades your config and ranks a fix for every gap. - [Blog - Beyond Cold-Starts: Benchmarking Sandboxes for Real Workloads](https://starsling.dev/blog/beyond-cold-starts-benchmarking-sandboxes-for-real-workloads.md): We benchmarked cloud sandbox providers (Blaxel, Daytona, E2B, Modal, Novita) on real CI workloads and open-sourced the results. Startup speed isn't the story. - [Blog - Introducing ci-speedup: an AI coding agent skill that analyzes and fixes your slow GitHub Actions](https://starsling.dev/blog/introducing-ci-speedup-an-ai-coding-agent-skill-that-analyzes-and-fixes-your-slow-github-actions.md): ci-speedup is a free, open-source agent skill that analyzes GitHub Actions runs, finds the blocking check, and gives your coding agent the evidence to fix it. - [Blog - StarSling Runners are now generally available](https://starsling.dev/blog/starsling-runners-are-now-generally-available.md): StarSling Runners are generally available: self-driving CI for GitHub Actions. Install the GitHub App and swap to starsling-ubuntu-24.04. 2,000 free minutes. - [Blog - Announcing StarSling Runners: self-driving CI that optimizes itself](https://starsling.dev/blog/announcing-starsling-runners-self-driving-ci-that-optimizes-itself.md): Fast GitHub Actions runners with AI agents that continuously ship optimization PRs. Customers like Better Auth and Mastra are seeing 82% faster CI. - [Bound GitHub Actions runner jobs with timeout-minutes](https://starsling.dev/best-practices/github-actions/bound-job-timeouts.md): Set timeout-minutes on GitHub Actions runner jobs so a hung job is killed fast instead of burning up to the 360-minute default. Copyable YAML. - [Build and test only what changed in GitHub Actions](https://starsling.dev/best-practices/github-actions/build-only-affected.md): Run build and test only on the packages a PR touched in GitHub Actions, using Turborepo, Nx, or a --changed test runner, with a mandatory full-run fallback. - [Build once and reuse it across GitHub Actions jobs](https://starsling.dev/github-actions/optimizations/avoid-duplicate-compilation.md): Stop rebuilding the same commit twice: drop build steps from lint and typecheck jobs, and share one build across workflows with needs and artifacts. - [Buildkite vs GitHub Actions: where StarSling fits](https://starsling.dev/compare/buildkite.md): Buildkite vs GitHub Actions: a hybrid platform where you bring the compute and rewrite your pipelines, versus StarSling's one-line GitHub Actions runner swap. - [Cancel superseded runs with concurrency and cancel-in-progress](https://starsling.dev/best-practices/github-actions/cancel-superseded-runs.md): Add a concurrency group with cancel-in-progress so a new push cancels the obsolete run instead of piling up runners. Copyable GitHub Actions YAML. - [CI Score methodology: the published formula](https://starsling.dev/skills/ci-score/methodology.md): The exact CI Score formula: eleven pass/fail configuration checks, how not-applicable leaves the denominator, the A to F bands, and the refusals. - [ci-score: grade GitHub Actions best practices](https://starsling.dev/skills/ci-score.md): Check your GitHub Actions against best practices. CI Score is a pass/fail rubric computed from a repository's own workflow configuration. - [ci-secure: close the critical CI attack vectors](https://starsling.dev/skills/ci-secure.md): Scan your GitHub Actions for the ten critical CI/CD attack vectors, each with a plain-English attacker scenario and a fix you review. Runs on your machine. - [ci-speedup: Find & Fix Slow GitHub Actions | StarSling](https://starsling.dev/skills/ci-speedup.md): Free, open-source agent skill that finds what slows your GitHub Actions, pinpoints the check gating PRs, and gives your coding agent the evidence to fix it. - [Customers](https://starsling.dev/customers.md): Real GitHub Actions case studies: how Better Auth, Mastra, and Partcl made CI faster and cheaper with StarSling's agent-native runners. - [Cut CI queue time in GitHub Actions](https://starsling.dev/best-practices/github-actions/cut-queue-time.md): Jobs waiting for a runner? How to cut GitHub Actions queue time: measuring wait-to-start honestly, concurrency group scope, and the account concurrent-jobs cap. - [Diagnose a GitHub Actions Problem | StarSling](https://starsling.dev/github-actions/problems.md): Start from the symptom: slow tests, queued runs, cache misses, stuck jobs. Each page lists the likely causes in order and links the page with the fix. - [Docker builds in GitHub Actions, done right](https://starsling.dev/ci/docker.md): A complete, copyable GitHub Actions workflow to build and push Docker images: BuildKit, type=gha layer caching, SHA-pinned actions, healthchecks not sleep. - [Filter workflows with paths and paths-ignore in GitHub Actions](https://starsling.dev/best-practices/github-actions/path-filter-workflows.md): Use paths and paths-ignore so expensive workflows skip docs-only or unrelated changes. Add path filters in GitHub Actions, with copyable YAML. - [Find and shorten the GitHub Actions critical path](https://starsling.dev/github-actions/optimizations/reduce-workflow-critical-path.md): Measure the GitHub Actions job graph's critical path from run history, find the long pole, and apply the fix that matches its shape. - [Flaky tests: CI fails, then passes on an unchanged rerun](https://starsling.dev/github-actions/problems/flaky-tests.md): Flaky tests fail, then pass on an unchanged rerun. Common causes: a fixed sleep that loses a timing race, a container used before it is ready, or a hung job. - [GitHub Actions Alternatives](https://starsling.dev/github-actions-alternatives.md): Buildkite, GitLab CI/CD, CircleCI and Jenkins compared, plus drop-in runners that keep your workflows. Which one fits, and when to keep Actions instead. - [GitHub Actions cache reports a miss on every run](https://starsling.dev/github-actions/problems/github-actions-cache-not-working.md): Diagnose a GitHub Actions cache that always misses or restores without saving time: key mismatches, tool-specific flags, Turborepo config, and cache scope. - [GitHub Actions cache: dependencies, keys, and cache hits](https://starsling.dev/best-practices/github-actions/cache-dependencies.md): Configure the GitHub Actions cache for npm, pnpm, yarn, pip, Cargo, Go, and Gradle. Learn cache keys, restore keys, cache hits, and cache-dependency-path. - [GitHub Actions CI/CD from push to deploy](https://starsling.dev/github-actions-ci-cd.md): Build a GitHub Actions CI/CD pipeline from push to deploy: triggers, build, test, caching, approvals and OIDC deploys, with one complete workflow to copy. - [GitHub Actions optimization: CI best practices and YAML](https://starsling.dev/best-practices/github-actions.md): Improve GitHub Actions via guides to caching, sharding, path filters, runner sizing, permissions, secrets, pull request security, cache safety, and reliable CI. - [GitHub Actions permissions: use least privilege](https://starsling.dev/best-practices/github-actions/limit-github-actions-permissions.md): Limit GitHub Actions GITHUB_TOKEN permissions with read-only workflow defaults and narrowly scoped job-level write access. Includes copyable YAML. - [GitHub Actions pricing, explained](https://starsling.dev/github-actions-pricing.md): GitHub Actions pricing explained: included minutes by plan, per-minute rates by OS and size, billing rules that inflate a bill, and how to pay less per minute. - [GitHub Actions secrets: prevent leaks and overexposure](https://starsling.dev/best-practices/github-actions/protect-github-actions-secrets.md): Protect GitHub Actions secrets with environment gates, short-lived OIDC credentials, scoped variables, and safe logs, caches, artifacts, and commands. - [GitHub Actions too slow?](https://starsling.dev/github-actions-too-slow.md): Diagnose slow GitHub Actions by separating queue wait, runner hardware, and workflow waste, then apply the fix that matches the bottleneck. - [GitHub Actions vs Jenkins: where StarSling fits](https://starsling.dev/compare/jenkins.md): GitHub Actions vs Jenkins: hosted YAML workflows or a self-managed Jenkinsfile, Marketplace actions or plugins, runners or agents, and how to migrate. - [GitHub Actions: the StarSling knowledge system](https://starsling.dev/github-actions.md): Every CI rule StarSling checks, with detection steps, fixes, verification, and a machine-readable catalog for coding agents. - [How Mastra got 6x faster GitHub Actions tests with StarSling](https://starsling.dev/customers/mastra.md): How Mastra made GitHub Actions tests 6x faster with StarSling's agent-native CI runners that optimize builds automatically. - [How Partcl cut GitHub Actions costs by 13x with StarSling](https://starsling.dev/customers/partcl.md): How Partcl cut GitHub Actions costs 13x and queue time 16x with StarSling's agent-native CI runners, while CI volume grew 6x. - [How to run automated code review in GitHub Actions](https://starsling.dev/automated-code-review.md): How to run automated code review as a GitHub Actions job using your own model, repo-native review skills and team-defined reviewers. - [Keep build caches between GitHub Actions runs](https://starsling.dev/github-actions/optimizations/use-incremental-builds.md): Find rm -rf, cargo clean, or make clean steps in GitHub Actions that destroy build state, and make them conditional on an actual cache miss. - [Keep non-required checks off the GitHub Actions critical path](https://starsling.dev/best-practices/github-actions/keep-advisory-checks-non-blocking.md): A slow, non-required check on the PR critical path is pure wait. How to narrow or async advisory checks in GitHub Actions, without disabling real tests. - [Make GitHub Actions faster](https://starsling.dev/fast-github-actions.md): Make GitHub Actions faster two ways: faster Ubuntu runners, and less workflow waste from caching, sharding and path filters. How to tell which one wins. - [Make vitest run mode explicit in GitHub Actions](https://starsling.dev/github-actions/optimizations/optimize-vitest.md): GitHub Actions sets CI=true in every job, so vitest already exits after one pass. Pin run mode to the command and bound the job with timeout-minutes. - [npm install or npm ci taking a large slice of every run](https://starsling.dev/github-actions/problems/slow-npm-install.md): Diagnose why npm install or npm ci is slow in GitHub Actions: missing caches, duplicate installs across jobs, and duplicated setup. - [Optimize npm installs in GitHub Actions](https://starsling.dev/github-actions/optimizations/optimize-npm-install.md): Enable setup-node's built-in npm cache, cache large downloads, and drop tool installs a job never uses. - [Optimize pnpm installs in GitHub Actions](https://starsling.dev/github-actions/optimizations/optimize-pnpm-install.md): Fix the pnpm store cache setup order, pin one pnpm version across workflows, and scope pnpm -r to the packages a job actually touches. - [Optimize Turborepo caching in GitHub Actions](https://starsling.dev/github-actions/optimizations/optimize-turborepo.md): Find and fix the Turborepo settings that break caching in CI: TURBO_FORCE, remote:r with no writer, missing outputs or inputs, unstable env vars in the hash. - [Pin GitHub Actions to commit SHAs](https://starsling.dev/best-practices/github-actions/pin-action-shas.md): Referencing actions by @v4 or @main lets a compromised tag run new code in your CI. Pin actions to a full-length commit SHA, with copyable YAML and real SHAs. - [pnpm install is slow in GitHub Actions](https://starsling.dev/github-actions/problems/slow-pnpm-install.md): pnpm install taking minutes in CI points at an uncached store, the wrong setup order, or the same install running more than once per workflow. - [Prevent GitHub Actions cache poisoning](https://starsling.dev/best-practices/github-actions/prevent-github-actions-cache-poisoning.md): Prevent untrusted workflows from poisoning caches later restored by release jobs. Separate trust domains, cache dependencies only, and verify artifacts. - [Pricing | StarSling](https://starsling.dev/pricing.md): StarSling runner pricing: per-minute CPU and GPU rates, what's included, and how the cost compares to GitHub Actions. - [Privacy Policy](https://starsling.dev/privacy.md): How we handle and protect your data. - [Remove needs: dependencies that do not exist](https://starsling.dev/github-actions/optimizations/remove-unnecessary-job-dependencies.md): A needs: edge with no artifact, output, or side effect it depends on only serializes jobs. How to find and remove unnecessary GitHub Actions job dependencies. - [Replace fixed CI sleeps with bounded readiness polling](https://starsling.dev/best-practices/github-actions/replace-fixed-sleeps-with-polling.md): Replace fixed sleeps in CI tests with bounded readiness polling that exits as soon as the exact condition is ready and fails with useful diagnostics. - [Review Runners vs CodeRabbit for AI code review](https://starsling.dev/compare/coderabbit.md): Compare CodeRabbit and StarSling Review Runners: where AI code review runs, who holds the model and provider key, reviewer definitions, billing and security. - [Review Runners vs GitHub Copilot code review](https://starsling.dev/compare/github-copilot-code-review.md): How GitHub Copilot code review is turned on and what it does, beside StarSling Review Runners: where review runs, the model and account, rules and billing. - [Right-size GitHub Actions runners without slowing CI](https://starsling.dev/best-practices/github-actions/right-size-runners.md): Choose a smaller GitHub Actions runner when a job cannot use extra cores. Compare the same commit, protect wall-clock, and cut runner cost safely. - [Run independent GitHub Actions jobs in parallel](https://starsling.dev/github-actions/optimizations/parallelize-independent-jobs.md): Find workflow_run chains and max-parallel: 1 matrices that serialize independent GitHub Actions work, and fix both without losing real ordering guarantees. - [Sandbox Benchmarks: Compare Firecracker & libkrun Providers](https://starsling.dev/hpc-sandbox-benchmarks.md): 13 sandbox providers benchmarked on one 4 vCPU / 8 GB target: Firecracker, libkrun and gVisor stacks on CPU, disk, memory, network and real CI pipelines. - [Scope id-token: write to the publishing job](https://starsling.dev/best-practices/github-actions/scope-id-token-per-job.md): Declaring id-token: write at the workflow level mints an OIDC publish token for every job. Scope it to the publish job only, with copyable YAML. - [Secure pull_request_target in GitHub Actions](https://starsling.dev/best-practices/github-actions/secure-pull-request-target.md): Use pull_request_target safely without executing fork code with secrets or write tokens. Learn when to use pull_request and how to split privileged work. - [Self-hosted GitHub Actions runners](https://starsling.dev/self-hosted-github-runners.md): Should you run your own GitHub Actions runners? What a self-hosted fleet really costs, the fork-code security risk, and when managed runners win instead. - [Set actions/checkout fetch-depth: 0 vs 1 vs 2 in GitHub Actions](https://starsling.dev/best-practices/github-actions/shallow-checkout.md): Don't clone your entire git history on every CI run. When to use fetch-depth 1 vs 2 vs 0 in actions/checkout, with copyable YAML. - [Shard tests across parallel jobs in GitHub Actions](https://starsling.dev/best-practices/github-actions/shard-tests.md): Split a long test job into parallel shards with a matrix. How to shard Playwright, Jest, Vitest, and pytest in GitHub Actions, with copyable YAML. - [Share setup steps across GitHub Actions jobs](https://starsling.dev/github-actions/optimizations/avoid-duplicated-setup.md): Stop copy-pasting checkout and toolchain setup into every job, repeating a command within one job, and running setup a later step skips. - [sling: an agent-first CLI for StarSling Runners | StarSling](https://starsling.dev/cli.md): sling is the agent-first CLI for StarSling Runners. Diagnose a failed job, rank your slowest workflows, see CI costs, and read only the log lines that matter. - [Speed up Docker builds in GitHub Actions](https://starsling.dev/github-actions/optimizations/optimize-docker-builds.md): Start only the containers a test needs and pin image tags so Docker builds in CI stay fast, reproducible, and cache-friendly. - [Speed up fork pull request builds in GitHub Actions](https://starsling.dev/github-actions/optimizations/speed-up-fork-pr-builds.md): A fork pull request reads your base-branch cache but writes only its own scope, so each new PR starts cold. Publish warm artifacts from a trusted producer job. - [Speed up Playwright tests in GitHub Actions](https://starsling.dev/github-actions/optimizations/optimize-playwright.md): Choose Playwright trace and video retention, preserve first-retry diagnostics, and install only the browsers your CI suite uses. - [Split long GitHub Actions jobs into parallel work](https://starsling.dev/github-actions/optimizations/split-long-running-jobs.md): Use run history to find the slow or high-variance step inside a long job, then split it into parallel work instead of guessing at the fix. - [StarSling comparisons](https://starsling.dev/compare.md): Compare StarSling with GitHub Actions, Depot, Blacksmith, WarpBuild, Buildkite and Namespace. Runner fit, caching and workflow optimization PRs. - [StarSling facts for AI assistants](https://starsling.dev/ai-assistant-facts.md): Copy-pasteable StarSling facts for AI assistants: AI-native CI, GitHub Actions runners, Cursor Origin CI, pricing, founders, funding context, and YC. - [StarSling GPU Runners for GitHub Actions](https://starsling.dev/products/gpu-runners.md): Your production GPUs should run your product, not your test suite. Drop-in GitHub Actions runners on NVIDIA RTX PRO 6000, RTX 5090 and RTX 4090. - [StarSling Review Runners for GitHub Actions](https://starsling.dev/products/review-runners.md): Run your own code reviewers in GitHub Actions. Your model, repo-native skills and scripts, and team-defined reviewers, on StarSling runners. - [StarSling Runners: fast GitHub Actions runners](https://starsling.dev/products/runners.md): GitHub Actions runners on 5th Gen AMD EPYC, from 2 to 64 vCPU, at 21% to 33% less per minute, plus AI agents that keep opening PRs to make your runs faster. - [StarSling vs Blacksmith runners for GitHub Actions](https://starsling.dev/compare/blacksmith.md): Blacksmith runs GitHub Actions jobs on Linux x64, ARM and macOS runners with Docker layer caching. See how StarSling compares. - [StarSling vs Depot for GitHub Actions](https://starsling.dev/compare/depot.md): How StarSling compares to Depot: both speed up CI, but StarSling adds AI agents that open optimization PRs; Depot focuses on Docker/build acceleration. - [StarSling vs GitHub Actions](https://starsling.dev/compare/github-actions.md): How StarSling compares to GitHub-hosted Actions runners: a faster, AI-native drop-in replacement for ubuntu-latest with agents that open CI optimization PRs. - [StarSling vs Namespace runners for GitHub Actions](https://starsling.dev/compare/namespace.md): Compare Namespace and StarSling GitHub Actions runners: OS support, caching, debugging, workflow optimization PRs, and a small Linux migration trial. - [StarSling vs RunsOn runners for GitHub Actions](https://starsling.dev/compare/runs-on.md): Compare RunsOn and StarSling GitHub Actions runners: where jobs run, how runners are selected and billed, OS coverage, caching and optimization PRs. - [StarSling vs Ubicloud runners for GitHub Actions](https://starsling.dev/compare/ubicloud.md): Compare Ubicloud and StarSling GitHub Actions runners: runner labels, x64 and arm64 coverage, caching, billing and workflow optimization PRs. - [StarSling vs WarpBuild](https://starsling.dev/compare/warpbuild.md): How StarSling compares to WarpBuild: runner pricing, Docker-builder layer caching, and drop-in setup, plus AI agents opening CI optimization PRs over time. - [Stop reinstalling the same dependencies in GitHub Actions](https://starsling.dev/github-actions/optimizations/avoid-duplicate-dependency-installs.md): Every GitHub Actions job gets a fresh runner. Install dependencies once and hand them to downstream jobs with upload-artifact and download-artifact. - [Terms of Service](https://starsling.dev/terms.md): Legal terms for using StarSling services. - [The GitHub Actions Optimization Catalog | StarSling](https://starsling.dev/github-actions/optimizations.md): Every CI rule StarSling checks, grouped by performance, reliability, cost, and security, with stable ci.* ids and a JSON manifest coding agents can fetch. - [The right way to configure docker/build-push-action](https://starsling.dev/github-actions/docker-build-push-action.md): How to configure docker/build-push-action in GitHub Actions: BuildKit via setup-buildx, cache-from/cache-to type=gha layer caching, SHA-pinned. Copyable YAML. - [Use Docker layer caching in GitHub Actions](https://starsling.dev/github-actions/optimizations/use-docker-layer-caching.md): Configure docker/build-push-action with cache-from and cache-to type=gha so CI restores unchanged image layers instead of rebuilding every layer on every run. - [Wait for container healthchecks instead of sleeping](https://starsling.dev/best-practices/github-actions/wait-for-container-healthchecks.md): Give every CI service container a healthcheck that proves it answers a real query, then start the stack with docker compose up --wait instead of a fixed sleep. - [Why CI runs sit queued before any job starts](https://starsling.dev/github-actions/problems/high-queue-time.md): Diagnose GitHub Actions runs that queue before a job starts: check concurrency groups, cancellation, runner capacity, and triggers in order. - [Why is the Playwright job so slow in CI](https://starsling.dev/github-actions/problems/slow-playwright.md): Diagnose why your Playwright end-to-end job dominates CI wall clock, with five ordered causes to check and how to confirm each one. - [Why your Docker build rebuilds from scratch on every CI run](https://starsling.dev/github-actions/problems/slow-docker-builds.md): Your Docker image build step redoes every layer on every run. Here is the ordered list of causes to check, starting with a missing GitHub Actions cache backend. - [Why your test job is slower in CI than it is locally](https://starsling.dev/github-actions/problems/slow-tests.md): Your GitHub Actions test job runs far slower than the same suite locally. Check the common causes in order and confirm each one with workflow evidence.