Pre-implementation blueprint generator. Reads spec artifacts and produces a single blueprint.md with complete, ready-to-use content for every task — so you can review, understand, and type through the implementation before /speckit.implement runs.
A Spec Kit community extension.
/speckit.specify → spec.md
/speckit.clarify → clarifications
/speckit.plan → plan.md
/speckit.tasks → tasks.md
↓ after_tasks hook (optional)
/speckit.blueprint.generate [mode] → blueprint.md ★
↓ before_implement hook (safety net)
/speckit.implement → code
/speckit.checklist → verify
Spec Kit's core workflow goes from tasks.md directly to /speckit.implement. This extension inserts a step between them: generate a complete blueprint, review it, then implement.
Reads tasks.md, spec.md, plan.md (and optionally data-model.md, contracts/) from the feature directory and generates blueprint.md containing:
- Complete content for every new file — ready to copy-paste or type through
- Before/after diffs for every modified file — with exact line references
- Key decisions with requirement traceability (FR-xxx → Task ID)
- Dependency-ordered implementation phases
- A task checklist at the end
Two modes:
| Mode | Output |
|---|---|
doc-only (default) |
blueprint.md only — nothing written to disk |
scaffold |
blueprint.md + new files on disk (structural files complete, core logic as TODO stubs) |
When AI writes all the code, the developer can lose familiarity with the codebase. The blueprint gives you a chance to:
- Read the implementation before it exists — understand what files will be created, how they connect, and what patterns they follow
- Type through it yourself — learn the project's conventions, spot design issues, and catch incorrect assumptions before any code is committed
The blueprint persists in specs/{feature}/ as a record of what was intended — useful for onboarding, design review, or revisiting decisions later.
specify extension add blueprintFrom repository directly:
specify extension add blueprint --from https://github.com/chordpli/spec-kit-blueprint/archive/refs/tags/v1.0.0.zip/speckit.blueprint.generate
Produces specs/{feature}/blueprint.md. No files created on disk.
/speckit.blueprint.generate scaffold
Produces blueprint.md + creates new files on disk. Structural files (type definitions, interfaces, configuration, wiring) are complete. Core implementation and test files contain TODO stubs with requirements from the spec. The developer references blueprint.md for the full implementation.
/speckit.implement
/speckit.implement can work entirely from blueprint.md. Review the blueprint, then run implement.
/speckit.blueprint.validate
/speckit.blueprint.validate specs/003-user-auth
Checks: blueprint exists, all referenced files exist on disk, TODO markers present in core files, no over-implemented scaffolds.
Exit code 0 = pass. Exit code 1 = failure.
| Argument | Description |
|---|---|
| (none) | doc-only — generate blueprint.md only |
scaffold |
Generate blueprint + stub files with TODO markers |
Requires: tasks.md in the feature directory.
Produces: specs/{feature}/blueprint.md — structured by phase and task, with full content blocks, before/after diffs, key decisions, implementation order, and checklist.
| Argument | Description |
|---|---|
| (none) | Auto-detect feature directory from current branch |
specs/NNN-name |
Use specified directory |
Checks: blueprint exists, new files exist, TODO markers in core files, no over-implementation.
One optional hook:
| Hook | When | Prompt |
|---|---|---|
after_tasks |
After /speckit.tasks completes |
"Generate blueprint from tasks?" |
Answer y to generate in doc-only mode. You can always run the command manually with a different mode afterward.
Disable hook: specify extension disable blueprint
The validate command runs a bundled Bash script:
bash .specify/extensions/blueprint/scripts/bash/validate-scaffold.sh specs/{feature}Color-coded output: green (pass), yellow (warning), red (failure). Usable in CI or pre-commit hooks.
| Error | Solution |
|---|---|
"Run /speckit.tasks first" |
Generate tasks before running blueprint |
| "blueprint.md not found" | Run /speckit.blueprint.generate first |
| "File MISSING" | Re-run scaffold mode or create the file manually |
| "No TODO markers found" | Core file may have been generated outside scaffold mode |
| Command not available | Check specify extension list, restart agent session, reinstall |
MIT — see LICENSE
- Issues: https://github.com/chordpli/spec-kit-blueprint/issues
- Spec Kit: https://github.com/github/spec-kit
Extension Version: 1.0.0 | Spec Kit: >=0.2.0