group-synastry

group-synastry

A Claude skill for computing detailed astrological birth charts and synastry/composite charts for a small private group of people, across multiple astrological systems (Western tropical, Vedic/Jyotish, Hellenistic, Chinese BaZi, Draconic, Heliocentric).

Status

Phases 1 & 2 built. Western tropical natal + synastry + composite + Davison + Markdown (Phase 1) plus .docx (via Node + docx-js) and .pdf (via LibreOffice headless) rendering (Phase 2). See plugins/group-synastry/skills/group-synastry/README.md for run instructions and plugins/group-synastry/skills/group-synastry/SKILL.md for the behavior contract. Phases 3–6 (Vedic/Hellenistic/BaZi, predictive, group ops, polish) remain deferred per spec §11.

Install

This repository is a Claude Code plugin marketplace. From a Claude Code session, register the marketplace, then install the skill from it:

/plugin marketplace add Bezoar/group-synastry
/plugin install group-synastry@group-synastry-marketplace

• The first command points Claude Code at this repo's .claude-plugin/marketplace.json.
• The second installs the group-synastry skill (the @group-synastry-marketplace suffix names the marketplace it came from). You can also run /plugin with no arguments to browse and install interactively.

After installing, just ask for a chart — e.g. "add me to my group and show my natal chart." On first use the skill runs a dependency check (scripts/check_env.py) and walks you through installing its one required Python package (pyswisseph), asking before it changes anything on your machine. Optional .docx / .pdf output needs Node and LibreOffice respectively; the skill offers those only when you request that format and otherwise falls back to Markdown. See the skill README for full setup and dependency details.

Usage

You drive the skill by talking to Claude in plain language — it runs the underlying scripts for you and asks before anything ambiguous or irreversible.

Managing people

The skill keeps a small private database of birth data (people.json, stored locally, never committed). Just ask:

• "Add Sam to my group — born March 3, 1990 at 7:15 AM in Seattle."
• "List everyone in my group." · "Show Sam's details."
• "Update Sam's birth time to 7:45 AM." · "Remove Sam from the group."

Claude prompts for anything missing. A birth date is required; an exact time and place are needed for the Ascendant, Midheaven, and houses. Timezones are stored as IANA names (e.g. America/Los_Angeles), so historical daylight-saving is handled correctly. If a birth time is unknown, the skill still computes planet positions but tells you the angles and houses are unavailable.

Managing cohorts

Cohorts are named groups — a family, a friend circle — that you collect lore about over time. Ask:

• "Create a cohort called Lumina with Sam, Alex, and Jordan."
• "Add Riley to Lumina." · "Make Lumina my active cohort."
• "Who's in Lumina?"

When a cohort is active, charts are filed under that cohort's folder, and free-form observations live in cohorts/<id>/notes.md — a shareable file, while the birth-data database stays private. A person can belong to more than one cohort.

Charts you can ask for

Chart	What it is	Example ask
Natal	one person's birth chart	"Show my natal chart."
Synastry	how two people relate, chart-to-chart	"How do Sam and Alex get along, chart-wise?"
Composite (midpoint)	the relationship's own "third chart"	"Make the composite for Sam and Alex."
Davison	a real chart cast at the midpoint in time and place of two births	"Do the Davison for Sam and Alex."
Time-range variants	several charts across an uncertain birth-time window	"Sam's birth time is fuzzy — show the range of possibilities."

For any chart you can choose the output format — inline Markdown (default), .docx, or .pdf — and the interpretation depth: none (just the data), brief, or full written analysis. Claude offers these if you don't say. Every natal and synastry chart always includes the Sun through Pluto plus Chiron, Black Moon Lilith, Ceres, Eris, the lunar nodes, and the Ascendant/Midheaven.

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