Harnesses

Codex

Adapter ID

codex

Vendor

OpenAI

Docs

developers.openai.com

Scope

Project

Native

4 of 10

Emulated

1 of 10

Planned

5 of 10

Round-trip

Digest-verified

OpenAI's terminal agent. TOML-based subagents and config; skills follow the cross-tool .agents standard.

Pack & unpack

# capture an existing Codex project as a bundle
uap pack --from codex

# install a bundle into a Codex project
uap unpack --to codex

# convert from Codex to any other harness
uap convert --from codex --to <harness>

Where components land

Paths are project-scope, relative to the directory you pack/unpack. Every location below is where Codex actually reads the component — verified against the official docs.

Component	Location	Support
Instructions	`AGENTS.md` Managed regions.	Native
Commands	`— (prompts are user-scope and deprecated)` Roadmap: install as user-invocable skills.	Planned
Subagents	`.codex/agents/<name>.toml` name / description / developer_instructions.	Native
Skills	`.agents/skills/<name>/`	Native
MCP servers	`.codex/config.toml` stdio + streamable HTTP; SSE is skipped (unsupported by Codex).	Native
Hooks	`.codex/hooks.json`	Planned
Permissions	`approval_policy / sandbox_mode` Mode-based, not rule-based.	Planned
Setup	`hook`	Planned
Env	`—`	Planned
Files	`project root`	Emulated

Fidelity notes

Components marked Native round-trip losslessly — pack(unpack(D)) ≡ D, digest-verified by the conformance suite.
Components marked Emulated install a faithful approximation and are flagged in the fidelity report so nothing is silently lost.
Components marked Planned are reported as skipped today; the target location shown is where the adapter will install them.