Raw thinking inside. Precise writing outside.
Janus is a two-channel communication skill for AI coding agents. It splits how the agent thinks from how the agent writes. It has two faces. One face turns inward. One face turns outward:
- Internal face (private): Terse. Reasoning, planning, scratch notes, and tool-call deliberation stay compressed. The agent drops articles and filler. It keeps all technical substance.
- External face (published): ASD-STE100 Simplified Technical English (STE). Every word the user reads uses full grammar, approved words, active voice, and short sentences.
One rule governs both: raw thinking inside, precise writing outside. The two channels never conflict. One is private. One is published.
Janus is the Roman god of gates, doorways, beginnings, and transitions. Art shows him with two faces that look in opposite directions at the same time. One face watches what comes in. One face watches what goes out. The month of January takes its name from him.
The name fits this skill for three reasons:
- Two faces, one head. The skill has one purpose but two channels. The inward face reasons in a terse, compressed style. The outward face writes in clear STE. They belong to the same skill, like the two faces of the god.
- A gate between inside and outside. Janus guards the threshold. This skill guards the threshold between private reasoning and published text. It makes sure the terse internal style never crosses into the output.
- A transition of form. Janus governs change from one state to the next. This skill changes verbose text into controlled, simple text.
- The agent reasons in a terse, compressed style. This is fast and cheap. It never reaches the user.
- The agent writes the answer in STE. This is clear and controlled. The user reads only this.
- Internal reasoning must never leak into the published answer.
- rewrite: return the STE-compliant rewrite of the input text.
- check: list the violations (quote the phrase, name the rule, give the fix). Then give the corrected STE text.
This skill is a single Markdown prompt. Copy skills/janus/SKILL.md into the
skills directory of your agent.
| Agent | Path |
|---|---|
| OpenCode | .opencode/skills/janus/SKILL.md |
| Claude Code | .claude/skills/janus/SKILL.md |
| Codex CLI | .agents/skills/janus/SKILL.md |
| Cursor | .cursor/skills/janus/SKILL.md |
| Gemini CLI | .gemini/skills/janus/SKILL.md |
| GitHub Copilot | .github/skills/janus/SKILL.md |
| Windsurf | .windsurf/skills/janus/SKILL.md |
| Cline | .cline/skills/janus/SKILL.md |
| Kiro | ~/.kiro/skills/janus/SKILL.md |
Agents without a native skill directory can read the prompt with a command such
as /read <path/to/SKILL.md>. The Markdown prompt works with any large language
model.
BEFORE:
Prior to the commencement of removal, the technician should ensure the hydraulic system has been depressurized.
AFTER:
WARNING: Make sure that the hydraulic system is not pressurized. Then start the removal procedure.
BEFORE:
It is recommended that the operator utilize the appropriate tool in the event that the fastener is seized.
AFTER:
If the fastener is jammed, use the correct tool.
BEFORE:
The panel, which is secured by four screws that must be removed prior to the extraction of the module, should then be set aside carefully.
AFTER:
Remove the four screws. Remove the panel. Put the panel in a safe place.
Janus activates when the user says "janus", "simplified technical english", "STE", "ASD-STE100", "think in caveman speak in STE", "controlled language", "rewrite for STE", or "STE check". It also activates on a request to make a procedure, manual, or warning clear for non-native or maintenance readers.
Janus does not activate for marketing copy or general prose that is unrelated to technical documentation.
- Do not apply STE to code, commit messages, legal text quoted verbatim, or the project's fixed technical terminology.
- Do not apply terse internal style to any user-facing output.
This skill approximates the public ASD-STE100 writing rules and common approved-word substitutions. For certified documentation, verify against the licensed ASD-STE100 specification. To turn the skill off, say "stop janus" or "normal mode".
janus/
├── README.md
├── LICENSE
├── CHANGELOG.md
├── skills/
│ └── janus/
│ └── SKILL.md
└── tests/
└── scenarios.md
skills/janus/SKILL.md is the whole skill. It is a single Markdown prompt with
YAML frontmatter. tests/scenarios.md lists eleven behavior checks with pass
and fail criteria.
Report issues and request features at github.com/fahrellgiovanny/janus/issues.
MIT. See LICENSE.
"Never use a long word where a short one will do." (George Orwell, Politics and the English Language)