openspec-sync-specs

Updates your main specs with changes from a delta spec without losing the change history.

Installation
Run `npx skills add "https://github.com/te-quanbzhang/skills-pool" --skill "openspec-sync-specs"` to install this skill, then follow its SKILL.md instructions for my next request.

Paste this into Claude Code, Cursor, or any agent that can run commands.

SKILL.mdShow the author's original SKILL.md
---
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.
license: MIT
compatibility: Requires openspec CLI.
metadata:
  author: openspec
  version: "1.0"
  generatedBy: "1.4.1"
---

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).

**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:
   ```bash
   openspec status --change "<name>" --json
   ```

   If status reports `actionContext.mode: "workspace-planning"`, explain that workspace spec sync is not supported in this slice and STOP. Do not fall back to repo-local paths or edit linked repos.

3. **Explore codebase with CodeGraph**

   Before applying changes to main specs, use CodeGraph to understand the codebase context for the capabilities being modified:

   a. **Extract key capability names and technical terms** from the delta spec file names and content

   b. **Run codegraph explore** to gather relevant code context:
      ```bash
      codegraph explore "<capability terms>"
      ```

   c. **Use codegraph findings when applying changes**:
      - Reference actual code symbols and patterns when updating main specs
      - Ensure spec changes align with the actual codebase architecture
      - Discover integration points that may need spec coverage

   > The codegraph context ensures spec changes are grounded in actual code implementation.

4. **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 with CodeGraph context**

   After applying all changes, summarize:
   - Which capabilities were updated
   - What changes were made (requirements added/modified/removed/renamed)
   - **CodeGraph findings** - relevant code areas that connect to these specs

**Delta Spec Format Reference**

```markdown
## 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

Mirrored from the author's public source. Install counts from the open skills registry.

The systems behind these skills get built for partners every week.

Partner with us