codex

codex is an agent for coding agents from tony/skills. It costs 0 tokens per session (2,564 once invoked), scanned A, original, MIT.

Validated with two independent Codex processes sharing the default CODEXHOME.

Agent

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add agents/tony/skills/codex
Clone the repo
git clone --depth 1 https://github.com/tony/skills

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for codex

README.md
[![agentmods](https://agentmods.dev/badge/agents/tony/skills/codex.svg)](https://agentmods.dev/agents/tony/skills/codex)
Your own site
<a href="https://agentmods.dev/agents/tony/skills/codex"><img src="https://agentmods.dev/badge/agents/tony/skills/codex.svg" alt="Measured on agentmods" height="20"></a>
Per session 0 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 2,564 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin unknown No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00000 $0.02564
Opus 5 $0.00000 $0.01282
Sonnet 5 $0.00000 $0.00513
Haiku 4.5 $0.00000 $0.00256

Measured today against content hash 14c761aa6624, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

codex scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured today.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

plugins/agent-messaging/references/agents/codex.md · 221 lines

How it starts

The opening of the file, as written. The whole thing — 221 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Adapter: Codex 0.149.0

Validated with two independent Codex processes sharing the default CODEX_HOME.

Upstream: openai/codex, release rust-v0.149.0, which introduced codex queue.

1. Identity

  • Own address: the thread UUID from $CODEX_THREAD_ID.
  • Where exposed: every agent-run command receives $CODEX_THREAD_ID; /status also displays it.
  • Stability: stable across the observed turn sequence. Resume and restart stability are UNKNOWN because neither was exercised.
  • Human-readable name: /rename <name> made the thread immediately resolvable by codex queue --thread <name>, on both trial threads. Collision behavior is UNKNOWN.

Evidence: T1.A, T1.B, T1.A-receipt.

2. Discovery

Paths below are relative to ${CODEX_HOME:-$HOME/.codex}.

  • Enumerate peers: no model-facing peer tool was found. A same-UID helper can join session_index.jsonl with held files under thread-writer-locks/; fuser supplies the owning process ID.
  • Scope: threads sharing a CODEX_HOME.
  • What a listing shows: thread UUID and name from the index; liveness and process ID from the writer lock. Queue depth is readable from queue_1.sqlite.
  • Blind spots: Claude sessions never appear. The codex agents interactive UI and app-server discovery were observed only from source and are not the adapter's portable discovery path.

Evidence: T1.C-disc and T1.O-disc.

3. Transports

codex-queue (send and receive)

$ codex queue \
    --thread <uuid-or-name> \
    --message "$(cat <<'RELAY'
[relay/1 from=A:codex@<thread> to=B id=<id> hop=0 want=none] <body>
RELAY
)"
  • Preconditions: the target thread exists in the same CODEX_HOME and is not archived. Exact UUIDs and exact names both work. Pass the body through a quoted heredoc as shown; interpolating it into a quoted literal breaks on an apostrophe such as it's done, and the remainder of the message is then read as shell syntax.
  • Success signal: stdout returns a durable queue-item UUID and the resolved target UUID. A same-UID helper can verify the row in queue_1.sqlite.
  • Daemon requirement: no long-running daemon was needed; a Claude shell invocation used the CLI's embedded app-server and enqueued in under one second once warm. The first call against a freshly started thread can block for minutes and enqueue nothing — measured at over two minutes twice and over four minutes once, the last outliving its own timeout and never completing even though the target was discoverable and its writer lock live. Do not retry: a second call double-delivers if the first was merely slow. Poll queued_items for the item id instead, and if nothing lands, report the transport unreachable rather than falling back to a live-only one.
  • Failure modes: missing-target, full-queue, and oversize errors are UNKNOWN empirically.

Read the full file on GitHub · 221 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. today First seen · 221 lines · 0 tokens per session scan A 14c761aa6624

Subscribe to this mod's changes

codex is an agent published in the GitHub repository tony/skills (2 stars, last pushed 5d ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 2,564 tokens. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.