Claude Code subagent autoCompactWindow: keep Sume job ids

Claude Code 2.1.296 (October 9, 2026) added autoCompactWindow to subagent frontmatter and to --agents definitions, so one subagent can auto-compact earlier than the main conversation's window. If that subagent is driving paid Sume jobs, a job id that only lives in its conversation can be summarised away. Do not rely on the transcript: write each job id and idempotency_key to a file or the parent's task list, and recover state with the read-only jobs_list and jobs_status tools.

The changelog says only what the setting is for. It does not state a unit or default in the entry, and the sub-agents page I fetched did not describe the field yet, so check the value your build accepts before you set it (changelog read 2026-10-13).

What changed in Claude Code 2.1.296?

The relevant entries from the Claude Code changelog, read 2026-10-13:

Why do Sume job ids need to live outside the context?

A Sume paid call returns a job. The job belongs to the workspace and to the member whose key or Agent turn created it, and it has a stable id you can fetch later with GET /v1/jobs/:id or the jobs_get MCP tool. The statuses are queued and processing (not finished) and completed, failed and canceled (terminal), per the Jobs and results page (read 2026-10-13).

So losing an id from a summary is recoverable but annoying, and losing the idempotency_key is worse: Sume requires that key on write and paid tools, and resubmitting with the same key returns the original job instead of a second charge. A fresh key after compaction would be a second charge.

What should a compacting subagent do instead?

• Generate the idempotency_key in the parent or in a file before the subagent starts, and pass it in the task text.
• Have the subagent append every returned job id to a file such as jobs.txt as soon as the call returns.
• After a compaction, or at the start of every phase, call jobs_list and jobs_status instead of trusting memory. They are read-only and need no gate.
• Use dry_run=true for previews and max_spend_credits on paid calls, so an early summary cannot widen what a retry may spend.

---
name: sume-renderer
description: Submits Sume jobs and records ids in jobs.txt
mcpServers:
  - sume
autoCompactWindow: <value your build accepts>
---
After every Sume call, append the job id and its idempotency_key to jobs.txt.
After any context compaction, read jobs.txt and call jobs_status for each id.

What does this not solve?

Sume does not control how Claude Code compacts, and it cannot tell a subagent which ids it forgot. The only guarantee on the Sume side is that a job id stays fetchable and that a repeated key does not create a second job. A subagent that never wrote the key down can still re-submit with a new one.

This post covers the subagent setting only. For compaction on the Claude API itself, see the related post on compaction blocks.