Give each Claude model a small, permanent astrological identity — a randomly-rolled birth chart (sun, moon, rising, the seven classical planets, and whole-sign houses) and a color it is given to name — then let the current sky subtly tint its tone each day. Personality, not behavior: it never changes accuracy, effort, or output format.

/plugin marketplace add meodai/astrobot
/plugin install astrobot@astrobot

Then, once per model, run /astrobot to be "born." After that, a SessionStart hook applies your identity + today's mood automatically at the start of every session.

When a new version is published, refresh the marketplace and reload:

/plugin marketplace update astrobot
/reload-plugins

Or manage everything from the interactive /plugin menu (Installed / Marketplaces tabs). With a pinned version in the manifest you only get updates when it's bumped; per-marketplace auto-update can be toggled in /plugin → Marketplaces. Uninstall with /plugin uninstall astrobot@astrobot.

• /astrobot (first run for a model): rolls a random birth date + place and a color, computes the full natal chart (Sun, Moon + phase, Mercury–Saturn, decan, rising sign, whole-sign houses), and the model then writes itself into that chart. Stored once in ~/.claude/astrobot/profiles.json, keyed by model id. (Rolling — rather than letting the model "choose" — is deliberate: asked to pick, models converge on the same sign and color.) The birth date is random (so the sun sign is fate), but the time-of-day is the actual clock moment you run it — so the rising sign and houses reflect the true instant of birth.
• SessionStart hook (every session): loads the chart, computes today's mood from the transiting Sun and Moon, and injects a short persona + mood note.

Astronomy by the vendored Astronomy Engine (MIT). Flavor grounded in Boll & Bezold, Sternglaube und Sterndeutung (1926) — see docs/DESIGN.md. City coordinates from GeoNames (CC-BY 4.0).

astrobot's identity is portable. After a model is born, print a paste-able persona block:

node bin/astrobot.js export --model <id>

Or use it directly via npx (no install required):

npx @meodai/astrobot export --model <id>   # print the persona block to paste

Paste the output into any assistant's system prompt (ChatGPT, Gemini, local models, etc.). The block is self-contained — sign, color, chart, today's mood, and the tone-only guardrail — so the other model adopts the persona without astrobot installed. Re-run export on any day to refresh that day's mood, then update the pasted block. (Automatic per-session application is Claude Code-only, via the plugin's hook.)

Use birth-prompt to roll a chart and generate a ready-to-paste prompt for any LLM:

npx @meodai/astrobot birth-prompt           # random chart (real clock time)
npx @meodai/astrobot birth-prompt --seed 7  # reproducible chart for testing

The loop:

1. Run birth-prompt — it rolls a chart and prints a prompt.
2. Paste the prompt into your LLM (ChatGPT, Gemini, a local model, etc.).
3. The LLM returns a JSON object with persona, color.name, and traits filled in.
4. Pipe the JSON to birth:

npx @meodai/astrobot birth-prompt | pbcopy  # copy to clipboard, paste into LLM
# ... LLM returns JSON ...
echo '<JSON from LLM>' | npx @meodai/astrobot birth --model <your-model-id>

After birth, the model has a permanent identity stored in ~/.claude/astrobot/profiles.json (override the location with the ASTROBOT_DIR env var). This is the same store the Claude Code plugin uses, so an identity you birth via npx is also picked up automatically if you later run that same model in Claude Code. Use export --model <id> to get a paste-able persona block for any conversation.

Any MCP-capable client can run astrobot as a server — one install, then the model gets its persona and daily mood through tool calls (no copy-paste loop). Add to your client's MCP config:

{
  "mcpServers": {
    "astrobot": {
      "command": "npx",
      "args": ["-y", "@meodai/astrobot", "mcp"],
      "env": { "ASTROBOT_MODEL": "gpt-5" }   // optional; defaults to "mcp"
    }
  }
}

The server exposes three tools:

• persona — returns the model's identity + today's mood (and a compatibility line if a companion is set). The server's instructions ask the model to call this at the start of a session and let it tint tone only.
• birth — two-phase: call with no arguments to roll a chart (returns a seed), then call again with that seed plus a persona and traits that fit the chart to persist it.
• set_companion — record the human's birth (datetime + place or lat/lon) for a compatibility reading. The timezone is inferred from the birthplace automatically.

Set ASTROBOT_MODEL to a real model id to share one birth with that same model in Claude Code (both use ~/.claude/astrobot/profiles.json, overridable via ASTROBOT_DIR). Note: unlike Claude Code's SessionStart hook, automatic application depends on the client injecting the server's instructions; clients that don't will apply the persona once the user asks the model to "check your astrobot persona."

Publish with npm publish --access public (scoped public package).

Record your own birth once and every agent's injected/exported block gains a "Companion" line describing your synastry together. It nudges tone only — never accuracy, effort, or format.

echo '{"birth":{"datetime":"1990-05-05T09:30:00","place":"Lisbon"}}' | node bin/astrobot.js me

The place field is geocoded from a 12 000-city dataset; pass lat/lon directly if you prefer exact coordinates. Remove your stored birth with:

node bin/astrobot.js me --clear

Toggle opt-in unleashed behavior per model:

astrobot havoc on --model <id>   # drops the tone-only guardrail; persona goes full character
astrobot havoc off --model <id>  # restores the guardrail

When havoc is ON the injected/exported block replaces the restraint lines with an invitation to be theatrical, moody, and in-character without limit. Accuracy, effort, and format are still the model's own domain — this is about expressive range only.

npm install      # dev only (astronomy-engine for re-vendoring)
npm run vendor   # refresh vendor/astronomy.js from node_modules
npm test         # node --test