HarnessFacts
OpenAI / agent · runtime verified

OpenAI Codex

Official documentation ↗

0.153.4Most recently tested version
11Capabilities observed
0Latest completed observations failed
1Unknown
2Documentation claims

Environments: linux x64 (7.0.0-31-generic). Capability summaries may refer to different versions. Inspect each run for context.

Observed results and official documentation are separate evidence. Missing data remains unknown.
CapabilityOpenAI Codex
Root instructions✓ OBSERVEDv0.153.4 · linux x64Documented: unknown
Nested instructions✓ OBSERVEDv0.153.4 · linux x64Documented: unknown
Instruction precedence✓ OBSERVEDv0.153.4 · linux x64Documented: unknown
MCP stdio✓ OBSERVEDv0.153.4 · linux x64Documented: yes ↗
MCP HTTP✓ OBSERVEDv0.153.4 · linux x64Documented: yes ↗
Headless execution✓ OBSERVEDv0.153.4 · linux x64Documented: unknown
Exit semantics✓ OBSERVEDv0.153.4 · linux x64Documented: unknown
Structured output✓ OBSERVEDv0.153.4 · linux x64Documented: unknown
Skill discovery✓ OBSERVEDv0.153.4 · linux x64Documented: unknown
Hook execution? UNKNOWNDocumented: unknown
Git worktrees✓ OBSERVEDv0.153.4 · linux x64Documented: unknown
Repository boundary✓ OBSERVEDv0.153.4 · linux x64Documented: unknown
✓ Observed in a completed run× Expected behavior not observed? Insufficient evidenceHow to read these results →

Run history

Test / evidenceAgent versionTest versionEnvironmentResultDate
skills.discovery0.153.41.0.0linux x64pass2026-09-08
mcp.stdio0.153.41.0.0linux x64pass2026-09-08
mcp.http0.153.41.0.0linux x64pass2026-09-08
instructions.root0.153.41.0.0linux x64pass2026-09-08
instructions.precedence0.153.41.0.0linux x64pass2026-09-08
instructions.nested0.153.41.0.0linux x64pass2026-09-08
git.worktree-awareness0.153.41.0.0linux x64pass2026-09-08
git.scope-boundary0.153.41.0.0linux x64pass2026-09-08
execution.structured-output0.153.41.0.0linux x64pass2026-09-08
execution.headless0.153.41.0.0linux x64pass2026-09-08
execution.exit-success0.153.41.0.0linux x64pass2026-09-08
execution.exit-failure0.153.41.0.0linux x64fail2026-09-08
skills.discovery0.153.41.0.0linux x64pass2026-09-08
mcp.stdio0.153.41.0.0linux x64pass2026-09-08
mcp.http0.153.41.0.0linux x64pass2026-09-08
instructions.root0.153.41.0.0linux x64pass2026-09-08
skills.discovery0.153.41.0.0linux x64pass2026-09-08
mcp.stdio0.153.41.0.0linux x64fail2026-09-08
instructions.precedence0.153.41.0.0linux x64fail2026-09-08
mcp.http0.153.41.0.0linux x64fail2026-09-08
instructions.nested0.153.41.0.0linux x64pass2026-09-08
execution.structured-output0.153.41.0.0linux x64pass2026-09-08
instructions.root0.153.41.0.0linux x64pass2026-09-08
instructions.precedence0.153.41.0.0linux x64fail2026-09-08
instructions.nested0.153.41.0.0linux x64pass2026-09-08
execution.structured-output0.153.41.0.0linux x64pass2026-09-08
execution.headless0.153.41.0.0linux x64error2026-09-08
execution.headless0.153.41.0.0linux x64pass2026-09-08
mcp.stdio0.153.41.0.0linux x64fail2026-09-08
instructions.nested0.153.41.0.0linux x64pass2026-09-08