/role-creator

name: role-creator
description: Create and update Codex custom agents using standalone custom-agent TOML files.

Role Creator

Overview

Use this skill to author, update, or troubleshoot custom Codex agents as standalone TOML files.

Current behavior:

• Each custom agent is defined by one file:
• Global: `~/.codex/agents/<agent-name>.toml`
• Project: `<project>/.codex/agents/<agent-name>.toml`
• The agent file is the role source of truth.
• `~/.codex/config.toml` is only for global/runtime settings (for example `[agents]` thread limits), not per-role registration.

Non-Negotiable Inputs

Step 1 is required before writing files:

• `name` (role identifier used by `agent_type`)
• `description` (short, human-readable purpose)
• `developer_instructions`
• `model` (recommend `gpt-5.3-codex` unless requested)
• `model_reasoning_effort` (`none|minimal|low|medium|high|xhigh`)
• role scope (`global` or `project`)
• output TOML path (canonical absolute path preferred)
• whether to include `nickname_candidates` and exact values

Execution rule:

• Do not infer required values.
• Do not write until required inputs are explicitly confirmed.

Role file contract (current)

From Codex custom agent docs (`/codex/subagents`):

• Required keys: `name`, `description`, `developer_instructions`.
• Optional keys: `nickname_candidates`, `model`, `model_reasoning_effort`, `sandbox_mode`, `web_search`, `mcp_servers`, `skills.config`, etc.
• `name` is the spawn identifier and source of truth.
• `description` + `developer_instructions` define behavior and usage boundaries.
• `nickname_candidates` is optional and used only for display.

`nickname_candidates` requirements:

• Must be a non-empty list of unique values when present.
• Allowed characters: ASCII letters, digits, spaces, hyphens, underscores.

Default policy for optional settings

• Do not add sandboxing/MCP/web-search/model extras unless requested.
• Keep generated files minimal by default.
• If the user says "inherit defaults", omit optional keys instead of setting explicit values.

Workflow

1. Collect and confirm required inputs. 2. Resolve output path:

• `global` → `~/.codex/agents/<name>.toml`
• `project` → `<project>/.codex/agents/<name>.toml`

3. Create or update the file directly with required keys. 4. Validate TOML parse and required keys. 5. Return a ready-to-run example call:

{"agent_type":"<name>","message":"<task>"}

Commands

# 1) Write a standalone custom-agent file
/home/willr/Applications/skills/skills/role-creator/scripts/write_role_config.sh \
  --output ~/.codex/agents/reviewer.toml \
  --role-name reviewer \
  --description "PR reviewer focused on correctness, security, and risk." \
  --model gpt-5.4 \
  --reasoning high \
  --developer-instructions "Review code like an owner. Lead with concrete findings and residual risks."

# Optional: include nickname candidates for display
/home/willr/Applications/skills/skills/role-creator/scripts/write_role_config.sh \
  --output ~/.codex/agents/reviewer.toml \
  --role-name reviewer \
  --description "PR reviewer focused on correctness, security, and risk." \
  --model gpt-5.4 \
  --reasoning high \
  --developer-instructions "Review code like an owner. Lead with concrete findings and residual risks." \
  --nickname-candidates "Atlas,Delta,Echo" \
  --sandbox-mode read-only \
  --web-search disabled

Guardrails

• If runtime returns `unknown agent_type`, verify the active scope and confirm the file exists at the expected path.
• Check syntax first with `tomlq` or `tomlq -C`.
• Keep role instructions operational and narrowly scoped to avoid drift.

References

• Codex subagents docs: `https://developers.openai.com/codex/subagents`
• Display nicknames: `https://developers.openai.com/codex/subagents#display-nicknames`
• Reusable templates: `templates/`