Check Impl Against Spec
- 14.6k installs
- 148 repo stars
- Updated July 24, 2026
- warpdotdev/common-skills
check-impl-against-spec is an agent skill that Compare a pull request's implementation against spec context in spec_context.md and feed any material mismatches into review.json. Use during PR review when app.
About
Compare a pull request's implementation against spec context in spec_context.md and feed any material mismatches into review.json. Use during PR review when approved or repository spec context is available. --- name: check-impl-against-spec description: Compare a pull request's implementation against spec context in spec_context.md and feed any material mismatches into review.json. Use during PR review when approved or repository spec context is available. --- # Check implementation against spec Use this skill only when `spec_context.md` exists during PR review. ## Goal Determine whether the implementation in the checked-out PR materially matches the approved spec context. This is a supplement to the normal code review, not a separate output. ## Inputs - `spec_context.md` contains the spec context to compare against. It may include both product spec content (intended behavior, acceptance criteria) and tech spec content (implementation details, file changes). - `pr_diff.txt` contains the annotated diff for the PR.
- Check implementation against spec
- `pr_diff.txt` contains the annotated diff for the PR.
- `pr_description.md` may contain additional scope or rationale.
- The working tree contains the PR branch contents.
- Read `spec_context.md` and extract the concrete commitments it makes:
Check Impl Against Spec by the numbers
- 14,629 all-time installs (skills.sh)
- +1,937 installs in the week ending Jul 28, 2026 (Skillselion tracking)
- Ranked #9 of 739 Git & Pull Requests skills by installs in the Skillselion catalog
- Security screen: LOW risk (skills.sh audit)
- Data as of Jul 28, 2026 (Skillselion catalog sync)
check-impl-against-spec capabilities & compatibility
- Capabilities
- check implementation against spec · `pr_diff.txt` contains the annotated diff for th · `pr_description.md` may contain additional scope · the working tree contains the pr branch contents · read `spec_context.md` and extract the concrete
- Use cases
- documentation
What check-impl-against-spec says it does
--- name: check-impl-against-spec description: Compare a pull request's implementation against spec context in spec_context.md and feed any material mismatches into review.json.
Use during PR review when approved or repository spec context is available.
--- # Check implementation against spec Use this skill only when `spec_context.md` exists during PR review.
## Goal Determine whether the implementation in the checked-out PR materially matches the approved spec context.
npx skills add https://github.com/warpdotdev/common-skills --skill check-impl-against-specAdd your badge
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| Installs | 14.6k |
|---|---|
| repo stars | ★ 148 |
| Security audit | 3 / 3 scanners passed |
| Last updated | July 24, 2026 |
| Repository | warpdotdev/common-skills ↗ |
What problem does check-impl-against-spec solve for developers using this skill?
Compare a pull request's implementation against spec context in spec_context.md and feed any material mismatches into review.json. Use during PR review when approved or repository spec context is avai
Who is it for?
Developers who need check-impl-against-spec patterns described in the cached skill documentation.
Skip if: Skip when docs are empty or the task is outside the skill's documented scope.
When should I use this skill?
Compare a pull request's implementation against spec context in spec_context.md and feed any material mismatches into review.json. Use during PR review when approved or repository spec context is avai
What you get
Actionable workflows and conventions from SKILL.md for check-impl-against-spec.
- review.json mismatch entries
- spec fidelity assessment
Files
Check implementation against spec
Use this skill only when spec_context.md exists during PR review.
Goal
Determine whether the implementation in the checked-out PR materially matches the approved spec context. This is a supplement to the normal code review, not a separate output.
Inputs
spec_context.mdcontains the spec context to compare against. It may include both product spec content (intended behavior, acceptance criteria) and tech spec content (implementation details, file changes).pr_diff.txtcontains the annotated diff for the PR.pr_description.mdmay contain additional scope or rationale.- The working tree contains the PR branch contents.
Process
1. Read spec_context.md and extract the concrete commitments it makes:
- required behaviors (from the product spec)
- required files or subsystems to change (from the tech spec)
- stated constraints
- required follow-up steps, validation, or migrations
2. Compare those commitments against the actual implementation in pr_diff.txt and the checked-out files. 3. Treat small implementation-level adjustments as acceptable when they preserve the spec's intent. Do not flag harmless differences in naming, structure, or low-level technique. 4. Flag a mismatch only when it is material, such as:
- required behavior in the product spec is missing
- the implementation contradicts a spec decision
- the change introduces significant unplanned scope
- a required validation, migration, or compatibility step from the tech spec is absent
Outputs
- Do not create a separate report file.
- Fold spec-alignment findings into
review.json. - Put broad spec-drift concerns in the review summary.
- Add inline comments only when the mismatch can be tied to changed lines in the diff.
- Treat material spec drift as at least an important concern.
- If the implementation matches the spec closely enough, do not add comments just to mention alignment.
Boundaries
- Do not require literal one-to-one implementation of the spec when the PR achieves the same outcome safely.
- Do not speculate about spec details that are not actually present in
spec_context.md. - Do not post to GitHub directly.
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Pick check-impl-against-spec over generic code review skills when an approved spec_context.md exists and you need spec-to-code fidelity checks on PRs.
FAQ
What does check-impl-against-spec do?
Compare a pull request's implementation against spec context in spec_context.md and feed any material mismatches into review.json. Use during PR review when approved or repository spec context is available.
When should I use check-impl-against-spec?
Compare a pull request's implementation against spec context in spec_context.md and feed any material mismatches into review.json. Use during PR review when approved or repository spec context is available.
Is check-impl-against-spec safe to install?
Review the Security Audits panel on this page before installing in production.