Natal Chart Lab MCP
Server Configuration
Describes the environment variables required to run the server.
| Name | Required | Description | Default |
|---|---|---|---|
| NATALCHARTLAB_URL | No | Set this to point the server at another deployment of the same API. |
Instructions
Guidance the server publishes about itself, which clients place ahead of the tool catalog so the model reads it before choosing anything.
This server publishes no instructions, or was last inspected before Glama recorded them.
Capabilities
Features and capabilities supported by this server
Protocol revision2025-11-25
| Capability | Details |
|---|---|
| tools | {
"listChanged": true
} |
Tools
Functions exposed to the LLM to take actions
| Name | Description |
|---|---|
| get_current_skyA | The sky right now: tropical zodiac sign and degree of the Sun, Moon and planets, the Moon's phase, illumination, next sign change and void-of-course windows for the next seven days, and which planets are retrograde or in shadow. Times are UTC. |
| get_planet_positionsA | Tropical zodiac positions (longitude, sign, degree, daily speed, retrograde flag) of the Sun, Moon, Mercury–Pluto, mean North Node and mean Black Moon Lilith at a UTC instant between 1800 and 2200. Apparent geocentric, checked against NASA JPL Horizons. |
| get_birth_placementsA | Sun, Moon and planet signs for a local birth date and clock time. Give the UTC offset that was in force at the birth (including daylight saving). Does not compute the rising sign or houses, which need the birth place; the result links to the free full calculator. |
| get_retrogradesA | Retrograde periods of Mercury through Pluto overlapping a date range, with station retrograde and direct times, signs and degrees, and pre-shadow and post-shadow dates. Covers retrogrades beginning 1950–2050. Defaults to the next 12 months. |
| get_moon_phasesA | New Moons, first quarters, Full Moons and last quarters in a date range, with the UTC time, zodiac sign and degree, Earth–Moon distance and any eclipse. Covers 1950–2050. Defaults to the next 60 days. |
Prompts
Interactive templates invoked by user choice
| Name | Description |
|---|---|
No prompts | |
Resources
Contextual data attached and managed by the client
| Name | Description |
|---|---|
No resources | |
TDQS
Scored across 5 tools
Each tool has a distinct astrological focus, but get_current_sky overlaps with get_planet_positions for current positions and with get_moon_phases for current lunar phase. The descriptions mostly clarify the boundaries through scope and extra data, so confusion is limited but possible.
All five tools use the same get_ + noun-phrase pattern: get_current_sky, get_planet_positions, get_moon_phases, get_birth_placements, get_retrogrades. The convention is predictable and easy to scan.
Five tools is well scoped for an astrology calculation server, with each tool covering a coherent calculation family. There is no obvious bloat or thin single-purpose surface.
The set covers planetary positions, lunar phases, retrogrades, current sky, and birth placements, but it explicitly omits houses and rising signs, which are core to a full natal chart. Aspects and broader chart calculations are also absent, though the external calculator link provides a partial workaround.