Can I continue a Sume Agent Completion with thread_id?

Not yet. The Agent Completions docs list continuing a prior thread with thread_id under not available yet, and say every completion runs in a fresh thread. Send what the follow-up needs in the next request.

Everything here is from Agent Completions and Run webhooks, read 2026-09-30.

What is thread_id in the receipt for?

The receipt returns a thread_id such as thr_... so you can tell which thread the run used. The docs present it as information, not as a request field to resume from.

What can I carry into the next call?

How do I pass the earlier output forward?

Read output from the completed run and put it into input of the next request. Use a new Idempotency-Key, because reusing a key with a different payload returns 409 idempotency_conflict.

curl -sS -X POST "https://api.sume.com/v1/agent/completions" \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: follow-up-002" \
  -d '{
        "instruction": "Write three shorter variants of the headline in input.",
        "input": { "headline": "Aurora Headphones, all day" },
        "generation_spend_cap_usd": 2
      }'

Do Format runs behave differently?

The run webhooks page notes that continuing a Format run starts a new run, which delivers its own single terminal webhook under the new run id. That page is about Formats, not Agent Completions.

Are completions shared with a team?

Not yet. The docs list team-owned threads under not available yet: Agent Completions are user-owned. Service-account keys cannot create them either and fail with 403 insufficient_scope and a details.reason of service_account_agent_completions_unsupported. Keys created before Agent Completions shipped lack the agent_completions scopes, and scopes cannot be added to an existing key.