/openspec-sync-specs

name: openspec-sync-specs
description: Sync delta specs from a change to main specs. Use when the user wants to update main specs with changes from a delta spec, without archiving the change.
allowed-tools: Bash(openspec:*)
license: MIT
compatibility: Requires openspec CLI.
metadata:
  author: openspec
  version: "1.0"
  generatedBy: "1.6.0"

Sync delta specs from a change to main specs.

This is an **agent-driven** operation - you will read delta specs and directly edit main specs to apply the changes. This allows intelligent merging (e.g., adding a scenario without copying the entire requirement).

**Store selection:** If the user names a store (a store is a standalone OpenSpec repo registered on this machine) or the work lives in one, run `openspec store list --json` to discover registered store ids, then pass `--store <id>` on the commands that read or write specs and changes (`new change`, `status`, `instructions`, `list`, `show`, `validate`, `archive`, `doctor`, `context`). Other commands do not take the flag. Hints printed by commands already carry the flag; keep it on follow-ups. Without a store, commands act on the nearest local `openspec/` root.

**Input**: Optionally specify a change name. If omitted, check if it can be inferred from conversation context. If vague or ambiguous you MUST prompt for available changes.

**Steps**

1. **If no change name provided, prompt for selection**

Run `openspec list --json` to get available changes. Use the **AskUserQuestion tool** to let the user select.

Show changes that have delta specs (under `specs/` directory).

**IMPORTANT**: Do NOT guess or auto-select a change. Always let the user choose.

2. **Resolve change context**

Run:

   openspec status --change "<name>" --json

3. **Find delta specs**

Use `artifactPaths.specs.existingOutputPaths` from the status JSON as the list of delta spec files.

Each delta spec file contains sections like:

• `## ADDED Requirements` - New requirements to add
• `## MODIFIED Requirements` - Changes to existing requirements
• `## REMOVED Requirements` - Requirements to remove
• `## RENAMED Requirements` - Requirements to rename (FROM:/TO: format)

If no delta specs found, inform user and stop.

4. **For each delta spec, apply changes to main specs**

For each repo-local capability delta spec path returned by the CLI:

a. **Read the delta spec** to understand the intended changes

b. **Read the main spec** at `openspec/specs/<capability>/spec.md` (may not exist yet)

c. **Apply changes intelligently**:

**ADDED Requirements:**

• If requirement doesn't exist in main spec → add it
• If requirement already exists → update it to match (treat as implicit MODIFIED)

**MODIFIED Requirements:**

• Find the requirement in main spec
• Apply the changes - this can be:
• Adding new scenarios (don't need to copy existing ones)
• Modifying existing scenarios
• Changing the requirement description
• Preserve scenarios/content not mentioned in the delta

**REMOVED Requirements:**

• Remove the entire requirement block from main spec

**RENAMED Requirements:**

• Find the FROM requirement, rename to TO

d. **Create new main spec** if capability doesn't exist yet:

• Create `openspec/specs/<capability>/spec.md`
• Add Purpose section (can be brief, mark as TBD)
• Add Requirements section with the ADDED requirements

5. **Show summary**

After applying all changes, summarize:

• Which capabilities were updated
• What changes were made (requirements added/modified/removed/renamed)

**Delta Spec Format Reference**

## ADDED Requirements

### Requirement: New Feature
The system SHALL do something new.

#### Scenario: Basic case
- **WHEN** user does X
- **THEN** system does Y

## MODIFIED Requirements

### Requirement: Existing Feature
#### Scenario: New scenario to add
- **WHEN** user does A
- **THEN** system does B

## REMOVED Requirements

### Requirement: Deprecated Feature

## RENAMED Requirements

- FROM: `### Requirement: Old Name`
- TO: `### Requirement: New Name`

**Key Principle: Intelligent Merging**

Unlike programmatic merging, you can apply **partial updates**:

• To add a scenario, just include that scenario under MODIFIED - don't copy existing scenarios
• The delta represents *intent*, not a wholesale replacement
• Use your judgment to merge changes sensibly

**Output On Success**

## Specs Synced: <change-name>

Updated main specs:

**<capability-1>**:
- Added requirement: "New Feature"
- Modified requirement: "Existing Feature" (added 1 scenario)

**<capability-2>**:
- Created new spec file
- Added requirement: "Another Feature"

Main specs are now updated. The change remains active - archive when implementation is complete.

**Guardrails**

• Read both delta and main specs before making changes
• Preserve existing content not mentioned in delta
• If something is unclear, ask for clarification
• Show what you're changing as you go
• The operation should be idempotent - running twice should give same result