Mini Spec

Purpose

Create the smallest useful SPEC.md that clarifies intent, names the likely failure mode, and gives the agent a verifiable target before planning or implementation.

When to use

Use when a project or feature is clear enough to define before implementation.

Inputs

• Clarified request
• CONTEXT.md if available
• Constraints
• Known commands
• Acceptance criteria or desired behavior

Workflow

1. State the objective.
2. Identify the user or use case.
3. Define observable acceptance criteria.
4. Record non-goals.
5. List likely failure modes and name the primary failure mode for this slice.
6. Record constraints.
7. List run, test, build, and verification commands.
8. Sketch project structure.
9. Define the smallest verification demo.
10. Record open questions.
11. When applicable, name compatibility seams that must remain import-compatible or output-compatible.
12. When applicable, record invalid-if constraints that would make the slice non-viable.

Outputs

• SPEC.md
• Explicit acceptance criteria
• Explicit non-goals
• Likely failure modes
• Verification demo

Compatibility seams to preserve

When applicable, list behavior that must remain import-compatible or output-compatible.

• Public imports / APIs: _TBD_
• CLI commands / flags: _TBD_
• JSON/schema/output contracts: _TBD_
• Existing tests whose meaning must remain valid: _TBD_
• Data/fixture semantics: _TBD_

Invalid if

• breaks a named compatibility seam
• weakens or rewrites existing tests merely to fit the implementation
• changes fixture/source data without explicit approval
• preserves behavior only through a new alternate path while breaking the old path
• changes forbidden/protected files
• adds dependencies or framework changes outside scope

Stop conditions

• The spec is under 100 lines unless risk justifies more.
• The next implementation slice is clear.
• Unresolved questions are recorded instead of hidden.

Anti-patterns

• Turning a small POC into a full product requirements document.
• Adding speculative future features.
• Writing vague acceptance criteria that cannot be verified.