Codex harness
Codex runtime v1 support contract
The supported and unsupported surfaces for Codex runtime v1. Part of the Codex harness runtime guide; Where each section moved lists every section.
V1 support contract
Supported in Codex runtime v1:
| Surface | Support | Why |
|---|---|---|
| OpenAI model loop through Codex | Supported | Codex app-server owns the OpenAI turn, native thread resume, and native tool continuation. |
| OpenClaw channel routing and delivery | Supported | Telegram, Discord, Slack, WhatsApp, iMessage, and other channels stay outside the model runtime. |
| OpenClaw dynamic tools | Supported | Codex asks OpenClaw to execute these tools, so OpenClaw stays in the execution path. |
| Prompt and context plugins | Supported | OpenClaw projects OpenClaw-specific prompt/context into the Codex turn while normally leaving Codex-owned base, model, and configured project-doc prompts in the native Codex lane. For ordinary policy-restricted turns without a native filesystem environment, OpenClaw carries the bounded workspace AGENTS.md snapshot as thread-level developer instructions. Ring-zero and other context-restricted internal modes suppress both paths. OpenClaw disables Codex's built-in personality for native threads so agent workspace personality files remain authoritative. Native Codex developer instructions accept only command guidance explicitly scoped to codex_app_server; legacy global command hints remain for non-Codex prompt surfaces. |
| Context engine lifecycle | Supported | Assemble, ingest, and after-turn maintenance run around Codex turns. Context engines do not replace native Codex compaction. |
| Dynamic tool hooks | Supported | before_tool_call, after_tool_call, and tool-result middleware run around OpenClaw-owned dynamic tools. |
| Lifecycle hooks | Supported as adapter observations | llm_input, llm_output, agent_end, before_compaction, and after_compaction fire with honest Codex-mode payloads. |
| Final-answer revision gate | Supported through native hook relay | Codex Stop is relayed to before_agent_finalize; revise asks Codex for one more model pass before finalization. |
| Native shell, patch, and MCP block or observe | Supported through native hook relay | Codex PreToolUse and PostToolUse are relayed for committed native tool surfaces, including MCP payloads on the pinned Codex app-server. Blocking is supported; argument rewriting is not. |
| Native permission policy | Supported through Codex app-server approvals and compatibility native hook relay | Codex app-server approval requests route through OpenClaw after Codex review. The PermissionRequest native hook relay is opt-in for native approval modes because Codex emits it before guardian review. |
| App-server trajectory capture | Supported | OpenClaw records the request it sent to app-server and the app-server notifications it receives. |
Not supported in Codex runtime v1:
| Surface | V1 boundary | Future path |
|---|---|---|
| Native tool argument mutation | Codex native pre-tool hooks can block, but OpenClaw does not rewrite Codex-native tool arguments. | Requires Codex hook/schema support for replacement tool input. |
| Editable Codex-native transcript history | Codex owns canonical native thread history. OpenClaw owns a mirror and can project future context, but should not mutate unsupported internals. | Add explicit Codex app-server APIs if native thread surgery is needed. |
tool_result_persist for Codex-native tool records |
That hook transforms OpenClaw-owned transcript writes, not Codex-native tool records. | Could mirror transformed records, but canonical rewrite needs Codex support. |
| Rich native compaction metadata | OpenClaw can request native compaction, but does not receive a stable kept/dropped list, token delta, completion summary, or summary payload. | Needs richer Codex compaction events. |
| Compaction intervention | OpenClaw does not let plugins or context engines veto, rewrite, or replace native Codex compaction. | Add Codex pre/post compaction hooks if plugins need to veto or rewrite native compaction. |
| Byte-for-byte model API request capture | OpenClaw can capture app-server requests and notifications, but Codex core builds the final OpenAI API request internally. | Needs a Codex model-request tracing event or debug API. |
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