codex

A guide for connecting Codex to Shipgate, a tool that checks coding-agent work against project rules. It explains how to read the checker's structured result and what to do when Shipgate is not installed.

In plain words
What is it for?
Use it when running Shipgate checks in Codex projects, discovering project-specific agent instructions, or verifying a committed change in continuous integration.
Why use it?
It gives Codex a consistent way to determine whether more action or human review is needed. It helps avoid treating a diagnostic message as the final decision.

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/threemoonslab/agents-shipgate/codex
Clone the repo
git clone --depth 1 https://github.com/ThreeMoonsLab/agents-shipgate
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 327 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original 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 $0.00327
Opus 5 $0.00000 $0.00163
Sonnet 5 $0.00000 $0.00065
Haiku 4.5 $0.00000 $0.00033

Measured 2d ago against content hash 996e38933033, 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 2d ago.

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.

docs/agents/codex.md · 38 lines

What it actually says

Use Agents Shipgate With Codex

Codex uses the shared agent-native protocol:

shipgate check --agent codex --workspace . --format agent-boundary-json

Parse stdout as shipgate.agent_boundary_result/v2. Switch only on control.state; follow control.next_action, control.allowed_next_commands, and control.human_review. Treat decision as diagnostic context only.

If the binary is missing, surface the schema-valid install fixture with control.state="agent_action_required", control.next_action.kind="install", and command pipx install agents-shipgate. After installation, rerun shipgate check; do not invent a natural-language decision.

Codex-specific discovery surfaces:

  • repo-level AGENTS.md
  • repo-scoped skill .agents/skills/agents-shipgate/
  • installable Codex plugin agents-shipgate

For committed PR verification, use the CI substrate after the local check:

agents-shipgate verify --workspace . --config shipgate.yaml --base origin/main --head HEAD --ci-mode advisory --format json

Read agents-shipgate-reports/agent-handoff.json first, then verifier.json, then verify-run.json, then report.json for reviewer evidence. Legacy agent-result.json surfaces are supporting/provisional compatibility projections for older automation consumers.

See protocol.md for the state machine, repair loop, policy discovery convention, and MCP read-only boundary.

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. 2d ago First seen · 38 lines · 0 tokens per session scan A 996e38933033

Subscribe to this mod's changes

codex is an agent published in the GitHub repository ThreeMoonsLab/agents-shipgate (87 stars, last pushed 3d ago), licensed Apache-2.0. It costs nothing until one of its globs matches a file; then it loads 327 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 2026-08-30.