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.
npx agentmods add skills/heapy/kortex/call-codexnpx skills add Heapy/kortex --skill call-codexgit clone --depth 1 https://github.com/Heapy/kortexWhat 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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00122 | $0.03874 |
| Opus 5 | $0.00061 | $0.01937 |
| Sonnet 5 | $0.00024 | $0.00775 |
| Haiku 4.5 | $0.00012 | $0.00387 |
Grade B, and why
call-codex scanned grade B with 2 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 yesterday.
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.
Reads agent configuration directoriesmediumAgent snooping
.claude/, .codex/, .gemini/ hold keys, settings and other credentials a mod has no legitimate need for.
`~/.codex/config.toml` supplies defaults (`model`, `model_reasoning_effort`, `sandbox_mode`, Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
- `-c sandbox_workspace_write.network_access=true` — dependency resolution, `git fetch`, curl. How it starts
The opening of the file, as written. The whole thing — 284 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Call Codex
Two modes
| Reviewer | Executor | |
|---|---|---|
| Job | break a claim | do a scoped task |
| Sandbox | read-only, always |
workspace-write plus what the task needs |
| The output that matters | the disagreement | the diff |
| Verified by | reading the code | reading the diff and running the tests |
One binary, one set of traps, two different grants and two different prompts. Picking the wrong grant is the usual failure: a reviewer with write access starts fixing instead of judging, and an executor without network dies on the first dependency fetch.
Prerequisites
Check which codex. Report and stop if it is absent.
~/.codex/config.toml supplies defaults (model, model_reasoning_effort, sandbox_mode,
sandbox_workspace_write.*). Pass everything the run depends on explicitly anyway: behavior
should not change because a default moved.
Mode 1 — Reviewer
A second reader for code that is already understood. Not a search tool, not a replacement for reading the code. It earns its cost in one situation: a claim exists — a review finding, a diagnosis, a design decision — and an independent model should try to break it.
Codex analyzes; the calling agent implements. Never let this mode write.
When to use
- A review produced findings and their reliability matters before acting on them.
- A diagnosis is plausible but unproven and a wrong fix would be expensive.
- Two explanations of the same failure both fit and the difference changes the fix.
- The user explicitly asks for codex.
When not to use
- To find code or navigate a repository. Grep is faster and free.
- To confirm something already verified. A run costs minutes and real tokens.
- To decide anything the user has already decided.
What ships with it
1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- yesterday First seen · 284 lines · 122 tokens per session scan B 81f075a0478d
call-codex is a skill published in the GitHub repository Heapy/kortex (5 stars, last pushed 4d ago), licensed Apache-2.0. It adds 122 tokens to every session and 3,874 once invoked, about $0.0006 per session on Opus 5. A static security scan graded it B with 2 findings (reads agent configuration directories, makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
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