What HarnessLink captures from Codex

Feature	In Codex	Details
Prompt history	Yes	`~/.codex/history.jsonl`.
Session transcripts	Yes	`~/.codex/sessions/YYYY/MM/DD/rollout-*.jsonl`, uploaded moments after they change.
Memory bank (autobank)	Yes	Every finished turn becomes a memory entry (subagent threads are skipped).
Gateway routing	Yes	A top-level `openai_base_url` in `~/.codex/config.toml`: `.../codex/chatgpt/codex` with a ChatGPT login, `.../codex/openai` with an API key.
Context hooks	Yes	`SessionStart`, `UserPromptSubmit`, `PreToolUse` and `PreCompact` in `~/.codex/hooks.json` (no `Stop`).
Memory tools (MCP)	Yes	`[mcp_servers.superpi]` in `~/.codex/config.toml`, running `superpi` with `args = ["mcp", "--harness", "codex"]`.
Org policy rules	Partly	Checked in `PreToolUse`. "Ask first" rules block, because Codex cannot ask from a hook.
Skills from templates	Yes	`hnl add <skill>` installs into `~/.agents/skills`, which Codex reads.
Resume in another harness	Yes	`hnl resume` reopens a session with `codex resume`.

Set up Codex

Install HarnessLink on macOS or Linux (Windows has its own one-liner).
```
curl -fsSL https://harnesslink.sh/install.sh | bash
```
Sign in once in your browser; setup then turns on what each harness on the machine supports.
```
hnl cloud setup
```

Or turn the pieces on one at a time.

hnl gateway connect codex
hnl cloud harnesses enable codex
hnl cloud autobank enable codex
hnl harness context codex
hnl mcp register --harness=codex --yes

Trust the new hooks once in Codex: run /hooks there. Codex skips hooks you have not trusted, and hnl reminds you until you do.
Check what is connected: plain hnl shows, for each harness, the gateway, transcripts, autobank, context and memory tools.
```
hnl
```

How memory reaches Codex

At session start the SessionStart hook adds your organisation's policy instructions and a brief of the project, up to 7,000 characters (Codex shows longer hook output only as a preview).

On each prompt the UserPromptSubmit hook adds up to 3 memory entries that share at least two distinctive words with your prompt, wherever they were banked: a decision made in Claude Code reaches Codex this way.

The hooks read files on the machine only (the local memory index and MAIN.md); they never call the cloud, so they stay fast and work offline.

When the model needs more it calls the memory tools. The MCP server is the HarnessLink service's own (superpi mcp). Its tools include memory_search (search your memory across projects and machines), memory_get (read one entry in full), memory_bank (record a decision or outcome), context_brief (a budgeted brief of the project), session_list and session_get.

Before Codex compacts the PreCompact hook saves a handoff entry, so a new session (/new) can pick the task up.

Limits

Codex runs a new or changed hook only after you trust it in /hooks.
Org policy: "ask first" rules block in Codex, and Codex's hosted web search cannot be hooked.
There is no Stop hook for Codex, so it does not prompt for a handoff; PreCompact still saves one.
The MCP server is registered only when the codex command is on your PATH.

Guides

Using HarnessLink: Using HarnessLink day to day: Ask, history, policies, shared memory, resuming sessions across harnesses, profile sync, templates, delegation, runs and cost.
Memory Banking: How HarnessLink turns each finished turn in omp, Claude Code, Codex, pi and Antigravity into a Markdown memory entry, when banking runs, and what reads it.
What HarnessLink captures from each harness: What HarnessLink captures from omp, Claude Code, Codex, pi, Antigravity and Cursor after setup, and how it stays a controller rather than a harness.

Other harnesses

Claude Code: Hooks, MCP memory tools, gateway and autobank
omp: Context extension, MCP memory tools, gateway and autobank
pi: Transcripts, autobank and gateway
Antigravity: Transcripts and one memory entry per conversation
Cursor: MCP memory tools, by hand; chats not captured

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