AC to Spec

Translate product requirements — in any format — into a filled-in spec template that can be fed directly to implementation skills.

Parameters: spec type (optional — inferred from content if omitted)

Usage examples:

/ac-to-spec @jira-ticket.md                    # infer spec type from content
/ac-to-spec new @prd-excerpt.md                # explicit: new feature spec
/ac-to-spec change @gherkin-scenarios.feature   # explicit: change spec
/ac-to-spec migrate                             # paste inline, explicit type
/ac-to-spec remove @slack-thread.txt            # explicit: removal spec

Spec Types

Input Formats

The skill accepts any of these — no preprocessing required:

• Gherkin — Given/When/Then scenarios
• Jira ticket — title, description, acceptance criteria checklist
• PRD prose — product requirements document sections
• User stories — As a [role], I want [action] so that [outcome]
• Bullet lists — informal requirements from Slack, email, meeting notes
• Free text — conversational description of what's needed

The skill extracts structure from whatever is provided.

Steps

1. Accept Input

The user provides requirements via @file reference or inline paste. Read the full content.

2. Determine Spec Type

If the user specified a type (new, change, migrate, remove), use it.

If not, infer from content signals:

If the signals are ambiguous or mixed, ask the user which type to use rather than guessing wrong. Frame the question with what you detected:

The requirements mention both adding new functionality and modifying existing behavior. Should this be a new spec (standalone feature) or a change spec (enhancement to an existing feature)?

3. Read the Target Template

Read the appropriate template from .agents/templates/{type}-spec.md to understand the full structure.

4. Read Existing Code (for change, migrate, remove)

For spec types that modify existing code, read the current state to ground the spec:

• change — read the feature's current models, presenter, UiState, events to accurately describe "Current Behavior"
• migrate — read the current implementation to document "From (Current State)"
• remove — read the target to enumerate files, dependencies, and dependents

For new specs, check whether a feature with a similar name already exists — if so, flag it and confirm with the user whether this is really new or should be change.

5. Extract and Map Requirements

Parse the input and map extracted information onto template sections. Work through the input methodically:

From any format, extract:

• What — the feature/change/target (→ Overview, Feature name)
• Why — business motivation (→ Business Context)
• Who — user role/persona (→ User story)
• Behaviors — observable outcomes (→ Acceptance criteria)
• Data — nouns, entities, fields mentioned (→ Domain Models)
• Actions — verbs, operations, user interactions (→ Use Cases, Events)
• Screens/UI — layout descriptions, states, flows (→ Screen & UI)
• Endpoints — API calls, services, data sources (→ API / Network)
• Conditions — edge cases, error handling, gating (→ Feature Flags, Error Responses)
• Constraints — performance, accessibility, market-specific (→ Constraints)

Gherkin-specific extraction:

• Given clauses → preconditions, current state, test setup context
• When clauses → user actions → Events, Use Cases
• Then clauses → expected outcomes → Acceptance criteria, UiState fields, test assertions
• And/But clauses → additional conditions, edge cases
• Scenario names → test scenario descriptions
• Scenario Outlines / Examples tables → parameterized behavior, enum types

Jira-specific extraction:

• Title → Overview summary
• Description → Business Context
• AC checklist → Acceptance criteria (preserve as-is, plus map to technical sections)
• Labels/components → Feature name, affected modules
• Priority/story points → Constraints (if they imply scope limits)
• Linked issues → Cross-Feature Dependencies

6. Fill the Template

Populate every section where the input provides enough information. Follow these rules:

• Fill confidently — if the AC clearly describes something, map it to the right section with concrete details
• Mark gaps for the grill (step 7) — if the AC implies something but lacks specifics, fill what you can and tag the gap internally with <!-- TODO: [what's missing] -->. These markers are temporary working state; they MUST be resolved during the grill step before the spec is finalized
• Don't leave silent gaps — if a section has zero signal from the AC, do not skip it; tag it with <!-- TODO: no signal in AC — [what the user needs to decide] --> so the grill step targets it
• Don't invent — never fabricate endpoint paths, field names, or UI layouts that aren't grounded in the input. Tag the gap and let the grill resolve it; never guess
• Acceptance criteria are unchecked — AC items in the spec use - [ ] (unchecked), never - [x]. The spec describes work to be done, not work already completed
• Preserve Out of Scope — if the AC defines out-of-scope items, carry them into the template's Out of Scope section verbatim. This prevents scope creep during implementation
• Preserve Constraints — if the AC mentions constraints, technical considerations, or implementation guidance (e.g., "keep the data layer clean for future swap"), carry them into the Constraints & Considerations section
• Use project conventions — when filling technical sections, follow the naming patterns and architecture documented in CLAUDE.md and .agents/standards/. For example, use CenterPostSubjectInteractor for streaming use cases, the {Name}RemoteDataSource / {Name}RemoteDataSourceImpl pattern for data sources. For TestTags, read an existing feature's TestTags file to match the actual naming convention used in the codebase (e.g., PascalCase vs snake_case)
• Preserve AC language — keep the PM's terminology in Business Context and Acceptance Criteria sections. Translate to technical terms in the implementation sections

7. Grill Until Clean

Before finalizing, scan the in-progress spec for unresolved markers and resolve every one with the user. Follow the grill-me skill on the working spec:

• Scan for <!-- TODO --> markers, empty - [ ] AC items, empty required header fields, raw template placeholders, and ... table cells
• Order branches by dependency (identity → business context → domain → API → use cases → repo → screen → cross-cutting)
• Explore the codebase before asking — confirm answers from sibling features, conventions, and existing infrastructure
• Ask one question at a time, always with a recommended answer and the tradeoff
• Write each resolution back into the spec immediately
• Append a ## Decisions section logging every resolved question + rationale

The conversion is not done until the spec is grill-clean. No <!-- TODO --> markers may survive into final output. If the user explicitly defers a decision, log it under ### Deferred in the Decisions section with the reason — do not leave it as a TODO.

8. Append Original Requirements

At the bottom of the spec, after all template sections, add a reference section preserving the original input:

markdown
1---
2
3## Original Requirements
4
5> **Source**: [format detected, e.g., "Gherkin scenarios", "Jira ticket", "PRD excerpt", "inline description"]
6> **Converted on**: {date}
7> **Spec type**: {type} (inferred / explicit)
8
9<details>
10<summary>Original acceptance criteria (click to expand)</summary>
11
12{verbatim original input, unmodified}
13
14</details>

This keeps the spec as the primary artifact while maintaining traceability to the PM's original language.

9. Present the Result

Output the complete spec. Tell the user:

1. Which spec type was used (and why, if inferred)
2. How many decisions were grilled (and how many, if any, were deferred — call out deferred ones explicitly)
3. Suggested next step — which skill to run with this spec (e.g., /add-feature @specs/{name}.md, /update order @specs/order-change.md). Because the grill step ran, the spec is implementation-ready; consumer skills can scaffold without further interrogation.

The user can save the output as a file (e.g., specs/{name}-spec.md) before feeding to the implementation skill.

Key Rules

• The spec is the artifact, not the AC — the output should be immediately usable by implementation skills without referencing the original AC
• Infer confidently, flag uncertainty — when the content clearly points to a spec type, just use it. When ambiguous, ask
• Grill until clean — never punt TODOs forward — the conversion is not done while gaps remain. Every unresolved decision must be answered (or explicitly deferred with a logged reason) before the spec is finalized. <!-- TODO --> markers are working state for step 6 only; they MUST NOT survive into final output
• Don't invent — grill instead — when the AC doesn't ground a value, do not guess. Ask the user during step 7, with a recommended answer and the tradeoff
• Stay grounded — every filled section should trace back to either the input or a grill answer. If you can't point to a source, it's invention
• Use project vocabulary — this codebase has specific patterns (CenterPost, Circuit, Metro, etc.). Use them in technical sections so the spec reads natively
• Respect the template — don't add sections that aren't in the template or skip sections that are. Delete-if-not-applicable instructions from the template headers still apply

No Verification Needed

This skill is read-only — it produces a document, not code changes. No verification step required.