---
id: 9369e53e-123c-4102-b69d-2a4705f2388e
type: code_pattern
title: "Command + background agent pattern for context-dependent async work"
tags: [claude-code, commands, agents, pattern, architecture]
importance: 0.6
confidence: 0.8
created: "2026-02-19T22:09:59.147931+00:00"
updated: "2026-02-19T22:09:59.147931+00:00"
---

Pattern for tasks needing conversation context but should run asynchronously.

## Pattern Structure

1. **Slash command** in `.claude/commands/` runs inline with full conversation context
2. **Command analyzes context** and builds structured summary
3. **Command spawns custom agent** from `.claude/agents/` in background via Task tool with `run_in_background=true`
4. **Agent receives summary** as prompt and does heavy lifting
5. **User gets control back** immediately

## Workflow

- Command has access to full conversation history → ideal for context analysis
- Agent runs asynchronously → ideal for time-consuming operations
- Structured summary bridges the two → cleanly separates concerns

## Real-World Example

`/save-memories` command:
- Command analyzes conversation, finds duplicate cutoff, builds memory summary
- Spawns memory-saver agent with summary
- User can continue working while agent stores items

## Implementation Notes

- Newly created agents require a **session restart** to appear in the `subagent_type` list
- Until then, use `subagent_type: general-purpose` as fallback
- Agent receives summary via prompt, not conversation history
- Task tool with `run_in_background=true` prevents blocking user

## Applicable To

Any task that:
- Requires analyzing session/conversation context
- Takes time to execute (network, storage, processing)
- Should not block the user
- Needs to defer execution to another agent