Evidence record / codex
A dated record of one change, kept so the writing that cites it can be checked. Compiled from the sources listed below by the research run, not written for reading. The judgment lives in the issues that cite it, below.
2026-10-24-codex-read-only-calls-can-overlap-and-full-history-forks-preserve-their-prefix
Read-only calls can overlap and full-history forks preserve their prefix. Native execution can overlap eligible read-only calls and cancel CodeMode work when interrupted. In 0.164.0, full-history subagent forks preserve the parent prefix by default, with a documented legacy-compaction exception. This supports reuse of existing context; the code does not prove a particular cache-hit rate or quota saving. Fresh-child dynamic-tool inheritance remains a separate default-off feature.
Channel: tagged-release. Half: capability. Date: 2026-10-23.
Operator consequence: Compare native parallel reads and forks against catalog-scanning, reinjection, and scheduling wrappers before retaining those layers. Measure accepted results, interruption latency, and context volume. Do not turn a prefix-preservation implementation into a claim that caching lasts forever or that child work is free.
Receipt
- https://github.com/openai/codex/commit/c9e0fffbbc05c36478686444f6ab1edbadfe2768
- https://github.com/openai/codex/commit/72c959528ee4ca74abdb8575fbbc4e36960a8c47
- https://github.com/openai/codex/commit/e1b9c9457ceca75a99b034a5df39ac48c3998d15
- https://github.com/openai/codex/blob/rust-v0.164.0/codex-rs/features/src/feature_configs.rs#L316-L319
Finding metadata
Run: 2026-10-24-weekly-digest-2026-10-13_2026-10-24-frontier-v0
Finding ID: 2026-10-24-codex-read-only-calls-can-overlap-and-full-history-forks-preserve-their-prefix
Source links
Primary links, including exact changelog lines when available.
- commit2026-10-24-codex-read-only-calls-can-overlap-and-full-history-forks-preserve-their-prefixgithub.com/openai/codex/commit/c9e0fffbbc05c36478686444f6ab1edbadfe2768commit2026-10-24-codex-read-only-calls-can-overlap-and-full-history-forks-preserve-their-prefixgithub.com/openai/codex/commit/72c959528ee4ca74abdb8575fbbc4e36960a8c47commit2026-10-24-codex-read-only-calls-can-overlap-and-full-history-forks-preserve-their-prefixgithub.com/openai/codex/commit/e1b9c9457ceca75a99b034a5df39ac48c3998d15tagged commit file2026-10-24-codex-read-only-calls-can-overlap-and-full-history-forks-preserve-their-prefixopenai/codex / codex-rs/features/src/feature_configs.rs#L316-L319
Versioned source: run artifact