Merge

---
name: "merge"
description: "Use this skill when the task requires merge capabilities."
command: /hub:merge
executor: LLM_BEHAVIOR
skill_id: engineering.cs_engineering.agenthub.merge
status: ADOPTED
security: {level: standard, pii: false, approval_required: false}
anchors:
  - engineering
  - agent
tier: 2
input_schema:
  - name: code_or_task
    type: string
    description: "Code snippet, script, or task description to process"
    required: true
output_schema:
  - name: result
    type: string
    description: "Primary output from merge"
---

# /hub:merge — Merge Winner

Merge the best agent's branch into the base branch, archive losing branches via git tags, and clean up worktrees.

## Usage

```
/hub:merge                                       # Merge winner of latest session
/hub:merge 20260317-143022                       # Merge winner of specific session
/hub:merge 20260317-143022 --agent agent-2       # Explicitly choose winner
```

## What It Does

### 1. Identify Winner

If `--agent` specified, use that. Otherwise, use the #1 ranked agent from the most recent `/hub:eval`.

### 2. Merge Winner

```bash
git checkout {base_branch}
git merge --no-ff hub/{session-id}/{winner}/attempt-1 \
  -m "hub: merge {winner} from session {session-id}

Task: {task}
Winner: {winner}
Session: {session-id}"
```

### 3. Archive Losers

For each non-winning agent:

```bash
# Create archive tag (preserves commits forever)
git tag hub/archive/{session-id}/{agent-id} hub/{session-id}/{agent-id}/attempt-1

# Delete branch ref (commits preserved via tag)
git branch -D hub/{session-id}/{agent-id}/attempt-1
```

### 4. Clean Up Worktrees

```bash
python {skill_path}/scripts/session_manager.py --cleanup {session-id}
```

### 5. Post Merge Summary

Write `.agenthub/board/results/merge-summary.md`:

```markdown
---
author: coordinator
timestamp: {now}
channel: results
---

## Merge Summary

- **Session**: {session-id}
- **Winner**: {winner}
- **Merged into**: {base_branch}
- **Archived**: {loser-1}, {loser-2}, ...
- **Worktrees cleaned**: {count}
```

### 6. Update State

```bash
python {skill_path}/scripts/session_manager.py --update {session-id} --state merged
```

## Safety

- **Confirm with user** before merging — show the diff summary first
- **Never force-push** — merge is always `--no-ff` for clear history
- **Archive, don't delete** — losing agents' commits are preserved via tags
- **Clean worktrees** — don't leave orphan directories on disk

## After Merge

Tell the user:
- Winner merged into `{base_branch}`
- Losers archived with tags `hub/archive/{session-id}/agent-{N}`
- Worktrees cleaned up
- Session state: `merged`

---

## Why This Skill Exists

Implement — Merge the winning agent

<!-- SR_40: auto-generated from frontmatter `purpose`/`description` (OPP-Phase3). Expand with domain-specific rationale. -->

## When to Use

Use this skill when the task requires merge capabilities.

<!-- SR_40: auto-generated from frontmatter `when`/`description` (OPP-Phase3). -->

## What If Fails

If this skill fails to produce the expected output: (1) verify input completeness, (2) retry with more specific context, (3) fall back to the parent workflow without this skill.

<!-- SR_40: auto-generated from frontmatter `what_if_fails` (OPP-Phase3). -->