Michael Bolin d2885dc3cd core: stabilize synthesized call output IDs (#30327) ...

## Why

Response item IDs represent stable conversation identity.
`ContextManager::for_prompt` repairs an unmatched call by synthesizing
an `"aborted"` output in the disposable prompt projection, but that
output previously had no ID. Assigning a fresh ID on every prompt build
would make retries and resumes change otherwise identical model context
and reduce prompt-cache reuse.

The concrete bug is that these normalization-created outputs bypass the
regular item-ID allocation path. Even with item IDs enabled, a prompt
could therefore contain an identified call paired with a synthetic
output whose `id` was missing. This change closes that gap by deriving
the output ID from the source call's item ID. For legacy calls that have
no item ID, the output remains ID-less because there is no stable source
identity to derive from.

The originating call already has a stable item ID under the item-ID
model introduced in #28814. A prompt-only output can therefore derive
stable identity from that call without mutating canonical history or
persisted rollouts. This addresses the failure exposed by #30311 while
keeping normalization read-only outside its detached prompt snapshot.

UUIDv5 is intentional here because it is the standard namespaced,
deterministic UUID construction. Using the output kind and source call
ID as the name produces the same UUID on every projection while keeping
output kinds in separate name domains. UUIDv7 would introduce randomness
and time, so keeping it stable would require persisting the synthetic
repair. UUIDv5 uses SHA-1 internally, but this is only an identity
mapping—not an authenticity or security boundary.

## What changed

- Derive a deterministic UUIDv5 ID for each synthesized call output from
the source call item ID.
- Use the Responses API prefix appropriate for function, custom-tool,
tool-search, and local-shell outputs.
- Preserve the existing insertion position immediately after the
unmatched call.
- Keep synthesized outputs prompt-only; no rollout, task-lifecycle,
compaction, or raw-response behavior changes.

## Testing

- `just test -p codex-core
for_prompt_assigns_stable_id_to_synthetic_output_without_reordering_history`
- `just test -p codex-core
synthetic_call_output_id_is_stable_across_resumes`
- `just test -p codex-core normalize_adds_missing_output`
- `just test -p codex-core response_item_ids`

d2885dc3cd · 2026-06-27 10:47:54 -07:00

History

..

common

Preserve namespaces on custom tool calls (#30302)

2026-06-27 09:54:56 -07:00

remote_env_windows

core: load AGENTS.md from foreign environments (#28958)

2026-06-18 15:06:23 -07:00

suite

core: stabilize synthesized call output IDs (#30327)

2026-06-27 10:47:54 -07:00

all.rs

[codex] Use expect in integration tests (#28441)

2026-06-15 21:53:47 -07:00

responses_headers.rs

feat: use run agent task auth for inference (#19051)

2026-06-24 22:31:41 -07:00