Files
gstack/ship/sections
Garry TanandClaude Fable 5 ae47c29b82 fix(review): skip nested codex spawns when already running under a Codex host (#2519)
/review executed inside a Codex host spawned the codex specialist passes
anyway — the same model reviewing itself, at multiplied cost (observed:
15M tokens for a single /review).

Detection per maintainer decision 7: a presence probe of the Codex session
env. A live Codex session exports CODEX_THREAD_ID and CODEX_SANDBOX into
every shell it spawns — verified during implementation against a live
`codex exec 'env | grep -i codex'` capture on codex 0.147.0
(CODEX_THREAD_ID, CODEX_SANDBOX=seatbelt, CODEX_SANDBOX_NETWORK_DISABLED=1,
CODEX_CI=1). The shared codexPreflight in scripts/resolvers/constants.ts
(consumed by all three review.ts army blocks: adversarial, codex plan
review, codex doc review) now yields CODEX_MODE=under_codex and instructs
exactly one printed notice — '[running under Codex — nested codex passes
skipped; set GSTACK_FORCE_CODEX_REVIEW=1 to force]'. The override env var
forces the nested passes for users who really want them. codex/SKILL.md.tmpl
Step 0.5 gains the same probe: /codex under a Codex host stops with a
one-line notice, since its whole value is a SECOND model's opinion.

test/codex-under-codex-detection.test.ts runs the rendered preflight bash
under all four env combinations (thread-id only, sandbox only, forced,
clean) and asserts the probe + notice render in the three preflight
consumers and the codex skill.

Fixes #2519

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
2026-08-16 10:59:35 -07:00
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