| name | prism-skill-author |
| description | Use this skill when Codex is asked to create, update, install, or manage custom Prism/Codex skills for an instance. |
Use this skill to create or update instance custom skills.
Custom skill definitions are owned by the site service and stored under /data/skills/<skill-name>/SKILL.md. Do not write custom skill definitions into CODEX_HOME unless the user explicitly asks for a temporary local experiment.
Rules
- Use lowercase kebab-case names:
example-skill.
- Store only skill instructions in
SKILL.md.
- Keep executable scripts, checkpoints, and generated outputs outside the skill folder, usually under
/data/custom/<experiment>/... if they must run from codex-runtime.
- Use the site internal skill endpoint when
PRISM_AGENT_API_BASE_URL and PRISM_AGENT_SERVICE_TOKEN are available.
- Keep new skills disabled-by-convention until a task or prompt explicitly requests them.
In deployed Prism instances, Codex Runtime usually receives APP_API_BASE_URL and APP_API_SERVICE_TOKEN, then exposes them to Codex as PRISM_AGENT_API_BASE_URL and PRISM_AGENT_SERVICE_TOKEN. If the PRISM_* names are missing, check the APP_* names before concluding the API is unavailable.
Do not use browser admin routes from Codex Runtime. Custom skill writes should go through /agent/skills with x-service-token.
Save A Custom Skill
POST the complete SKILL.md content:
curl -fsSL \
-X POST \
-H "content-type: application/json" \
-H "x-service-token: $PRISM_AGENT_SERVICE_TOKEN" \
"$PRISM_AGENT_API_BASE_URL/agent/skills" \
-d @skill-payload.json
Payload shape:
{
"name": "example-skill",
"content": "---\nname: example-skill\ndescription: Use this skill when...\n---\n\nSkill instructions go here.\n"
}
After saving, the skill appears in the admin Skills tab and can be requested by tasks through instructionConfig.requestedSkills.
