Birth Chart

Overview

Planet positions are apparent geocentric longitudes on the true ecliptic of date, from the astronomy-engine ephemeris. House cusps use Placidus by default, with whole sign and equal houses as options. When no timezone is given it is looked up from the coordinates, and births from before a region adopted standard time use the birthplace's local mean time.

Live Test Birth Chart Skill →

The tool

Once your client is connected to the VerveKit server, this appears in its tool list as BirthChart. It is read-only and open-world — it fetches and never mutates anything on your side — so most clients call it without asking you to confirm.

Tool call

{
  "name": "BirthChart",
  "arguments": {
    "date": "1990-06-15",
    "time": "14:30",
    "lat": "40.7128",
    "lon": "-74.006"
  }
}

You do not name the tool yourself; the model picks it. Asking about 1990-06-15 in the terms this skill covers is enough for it to reach for BirthChart on its own — naming it explicitly also works, and is the way to force the call.

Connecting

One server URL covers every skill in the catalog, including this one. Authorization is OAuth: the client opens a browser once, and there is no key to paste into a config file.

{
  "mcpServers": {
    "vervekit": {
      "url": "https://api.vervekit.com/v1/mcp"
    }
  }
}

Per-client setup — Claude, Cursor, VS Code, ChatGPT — is on the MCP setup page.

Arguments

These are the properties on the tool's inputSchema, so a well-behaved client validates them before the call is made. Premium arguments are accepted on every plan but only take effect on plans that include them.

Argument	Type	Description
`date`Required	string	The birth date (YYYY-MM-DD or MM-DD-YYYY), between 1700 and 2200
`time`Required	string	The local birth time in 24-hour HH:mm format
`lat`Required	number	The latitude of the birthplace range -90–90
`lon`Required	number	The longitude of the birthplace (east positive) range -180–180
`timezone`Optional	string	An IANA timezone name (America/New_York) or a UTC offset (+05:30). Looked up from the coordinates when omitted timezone
`houseSystem`Optional	string	The house system to use `placiduswholesignequal` default placidus

What the model gets back

The result carries a structuredContent object matching the tool's declared outputSchema, so a client reads fields without parsing prose. status is "ok" and error is null on success; a null field means the value was not available for that input, not that the call failed.

Result

{
  "status": "ok",
  "error": null,
  "data": {
    "birth": {
      "localTime": "1990-06-15T14:30",
      "utcTime": "1990-06-15T18:30:00Z",
      "timezone": "America/New_York",
      "utcOffset": "-04:00",
      "offsetSource": "location",
      "latitude": 40.7128,
      "longitude": -74.006
    },
    "houseSystem": "placidus",
    "sunSign": "Gemini",
    "moonSign": "Pisces",
    "risingSign": "Libra",
    "ascendant": {
      "sign": "Libra",
      "degree": 13.7,
      "longitude": 193.6954,
      "formatted": "13°42' Libra"
    },
    "midheaven": {
      "sign": "Cancer",
      "degree": 15.92,
      "longitude": 105.9221,
      "formatted": "15°55' Cancer"
    },
    "planets": [
      {
        "name": "Sun",
        "sign": "Gemini",
        "degree": 24.39,
        "longitude": 84.3882,
        "formatted": "24°23' Gemini",
        "house": 9,
        "retrograde": false,
        "speed": 0.9551
      },
      {
        "name": "Moon",
        "sign": "Pisces",
        "degree": 18.99,
        "longitude": 348.9903,
        "formatted": "18°59' Pisces",
        "house": 6,
        "retrograde": false,
        "speed": 13.4613
      },
      {
        "name": "Mercury",
        "sign": "Gemini",
        "degree": 6.16,
        "longitude": 66.1572,
        "formatted": "6°09' Gemini",
        "house": 8,
        "retrograde": false,
        "speed": 1.7285
      },
      {
        "name": "Venus",
        "sign": "Taurus",
        "degree": 19.1,
        "longitude": 49.0959,
        "formatted": "19°06' Taurus",
        "house": 8,
        "retrograde": false,
        "speed": 1.1763
      },
      {
        "name": "Mars",
        "sign": "Aries",
        "degree": 11.24,
        "longitude": 11.2357,
        "formatted": "11°14' Aries",
        "house": 6,
        "retrograde": false,
        "speed": 0.7186
      },
      {
        "name": "Jupiter",
        "sign": "Cancer",
        "degree": 15.95,
        "longitude": 105.9482,
        "formatted": "15°57' Cancer",
        "house": 10,
        "retrograde": false,
        "speed": 0.2168
      },
      {
        "name": "Saturn",
        "sign": "Capricorn",
        "degree": 24.02,
        "longitude": 294.016,
        "formatted": "24°01' Capricorn",
        "house": 4,
        "retrograde": true,
        "speed": -0.0589
      },
      {
        "name": "Uranus",
        "sign": "Capricorn",
        "degree": 8.15,
        "longitude": 278.1534,
        "formatted": "8°09' Capricorn",
        "house": 3,
        "retrograde": true,
        "speed": -0.039
      },
      {
        "name": "Neptune",
        "sign": "Capricorn",
        "degree": 13.71,
        "longitude": 283.7101,
        "formatted": "13°43' Capricorn",
        "house": 3,
        "retrograde": true,
        "speed": -0.0251
      },
      {
        "name": "Pluto",
        "sign": "Scorpio",
        "degree": 15.4,
        "longitude": 225.3967,
        "formatted": "15°24' Scorpio",
        "house": 2,
        "retrograde": true,
        "speed": -0.0201
      },
      {
        "name": "North Node",
        "sign": "Aquarius",
        "degree": 9.68,
        "longitude": 309.68,
        "formatted": "9°41' Aquarius",
        "house": 4,
        "retrograde": true,
        "speed": -0.053
      }
    ],
    "houses": [
      {
        "house": 1,
        "sign": "Libra",
        "degree": 13.7,
        "longitude": 193.6954,
        "formatted": "13°42' Libra"
      },
      {
        "house": 2,
        "sign": "Scorpio",
        "degree": 10.77,
        "longitude": 220.7713,
        "formatted": "10°46' Scorpio"
      },
      {
        "house": 3,
        "sign": "Sagittarius",
        "degree": 11.92,
        "longitude": 251.9193,
        "formatted": "11°55' Sagittarius"
      },
      {
        "house": 4,
        "sign": "Capricorn",
        "degree": 15.92,
        "longitude": 285.9221,
        "formatted": "15°55' Capricorn"
      },
      {
        "house": 5,
        "sign": "Aquarius",
        "degree": 19.31,
        "longitude": 319.3054,
        "formatted": "19°18' Aquarius"
      },
      {
        "house": 6,
        "sign": "Pisces",
        "degree": 18.9,
        "longitude": 348.9027,
        "formatted": "18°54' Pisces"
      },
      {
        "house": 7,
        "sign": "Aries",
        "degree": 13.7,
        "longitude": 13.6954,
        "formatted": "13°42' Aries"
      },
      {
        "house": 8,
        "sign": "Taurus",
        "degree": 10.77,
        "longitude": 40.7713,
        "formatted": "10°46' Taurus"
      },
      {
        "house": 9,
        "sign": "Gemini",
        "degree": 11.92,
        "longitude": 71.9193,
        "formatted": "11°55' Gemini"
      },
      {
        "house": 10,
        "sign": "Cancer",
        "degree": 15.92,
        "longitude": 105.9221,
        "formatted": "15°55' Cancer"
      },
      {
        "house": 11,
        "sign": "Leo",
        "degree": 19.31,
        "longitude": 139.3054,
        "formatted": "19°18' Leo"
      },
      {
        "house": 12,
        "sign": "Virgo",
        "degree": 18.9,
        "longitude": 168.9027,
        "formatted": "18°54' Virgo"
      }
    ],
    "aspects": [
      {
        "planet1": "Moon",
        "planet2": "Venus",
        "aspect": "sextile",
        "angle": 60,
        "orb": 0.11,
        "applying": true
      },
      {
        "planet1": "Jupiter",
        "planet2": "Pluto",
        "aspect": "trine",
        "angle": 120,
        "orb": 0.55,
        "applying": false
      },
      {
        "planet1": "Mars",
        "planet2": "North Node",
        "aspect": "sextile",
        "angle": 60,
        "orb": 1.56,
        "applying": false
      },
      {
        "planet1": "Neptune",
        "planet2": "Pluto",
        "aspect": "sextile",
        "angle": 60,
        "orb": 1.69,
        "applying": false
      },
      {
        "planet1": "Jupiter",
        "planet2": "Neptune",
        "aspect": "opposition",
        "angle": 180,
        "orb": 2.24,
        "applying": false
      },
      {
        "planet1": "Mars",
        "planet2": "Neptune",
        "aspect": "square",
        "angle": 90,
        "orb": 2.47,
        "applying": true
      },
      {
        "planet1": "Moon",
        "planet2": "Jupiter",
        "aspect": "trine",
        "angle": 120,
        "orb": 3.04,
        "applying": false
      },
      {
        "planet1": "Mars",
        "planet2": "Uranus",
        "aspect": "square",
        "angle": 90,
        "orb": 3.08,
        "applying": false
      },
      {
        "planet1": "Venus",
        "planet2": "Jupiter",
        "aspect": "sextile",
        "angle": 60,
        "orb": 3.15,
        "applying": false
      },
      {
        "planet1": "Mercury",
        "planet2": "North Node",
        "aspect": "trine",
        "angle": 120,
        "orb": 3.52,
        "applying": true
      },
      {
        "planet1": "Moon",
        "planet2": "Pluto",
        "aspect": "trine",
        "angle": 120,
        "orb": 3.59,
        "applying": false
      },
      {
        "planet1": "Venus",
        "planet2": "Pluto",
        "aspect": "opposition",
        "angle": 180,
        "orb": 3.7,
        "applying": false
      },
      {
        "planet1": "Mars",
        "planet2": "Jupiter",
        "aspect": "square",
        "angle": 90,
        "orb": 4.71,
        "applying": true
      },
      {
        "planet1": "Venus",
        "planet2": "Saturn",
        "aspect": "trine",
        "angle": 120,
        "orb": 4.92,
        "applying": true
      },
      {
        "planet1": "Moon",
        "planet2": "Saturn",
        "aspect": "sextile",
        "angle": 60,
        "orb": 5.03,
        "applying": true
      },
      {
        "planet1": "Mercury",
        "planet2": "Mars",
        "aspect": "sextile",
        "angle": 60,
        "orb": 5.08,
        "applying": true
      },
      {
        "planet1": "Moon",
        "planet2": "Neptune",
        "aspect": "sextile",
        "angle": 60,
        "orb": 5.28,
        "applying": false
      },
      {
        "planet1": "Venus",
        "planet2": "Neptune",
        "aspect": "trine",
        "angle": 120,
        "orb": 5.39,
        "applying": false
      },
      {
        "planet1": "Sun",
        "planet2": "Moon",
        "aspect": "square",
        "angle": 90,
        "orb": 5.4,
        "applying": true
      },
      {
        "planet1": "Uranus",
        "planet2": "Neptune",
        "aspect": "conjunction",
        "angle": 0,
        "orb": 5.56,
        "applying": false
      },
      {
        "planet1": "Pluto",
        "planet2": "North Node",
        "aspect": "square",
        "angle": 90,
        "orb": 5.72,
        "applying": false
      },
      {
        "planet1": "Jupiter",
        "planet2": "Uranus",
        "aspect": "opposition",
        "angle": 180,
        "orb": 7.79,
        "applying": false
      }
    ],
    "elements": {
      "fire": 1,
      "earth": 4,
      "air": 2,
      "water": 3
    },
    "modalities": {
      "cardinal": 5,
      "fixed": 2,
      "mutable": 3
    }
  }
}

Response fields

Paths are relative to data. Premium fields are absent rather than zeroed on plans that do not include them, so check for presence instead of comparing to 0.

Field	Type	Example	Description
`birth`	object	`{…}`	The birth moment and place the chart was calculated for
`birth.localTime`	string	`1990-06-15T14:30`	The local birth time as given
`birth.utcTime`	string	`1990-06-15T18:30:00Z`	The birth time converted to UTC (ISO 8601)
`birth.timezone`	string	`America/New_York`	The IANA timezone used, or null when a fixed offset was given
`birth.utcOffset`	string	`-04:00`	The UTC offset applied, such as -04:00
`birth.offsetSource`	string	`location`	Where the offset came from: timezone, offset, location or local mean time
`birth.latitude`	number	`40.7128`	Latitude of the birthplace
`birth.longitude`	number	`-74.006`	Longitude of the birthplace
`houseSystem`	string	`placidus`	The house system used
`sunSign`	string	`Gemini`	The zodiac sign of the sun
`moonSign`	string	`Pisces`	The zodiac sign of the moon
`risingSign`	string	`Libra`	The rising sign (the sign of the ascendant)
`ascendant`	object	`{…}`	The ascendant: sign, degree within the sign, ecliptic longitude and a formatted position
`ascendant.sign`	string	`Libra`	Sign of the ascendant
`ascendant.degree`	number	`13.7`	Degree within the sign (0-30)
`ascendant.longitude`	number	`193.6954`	Ecliptic longitude (0-360)
`ascendant.formatted`	string	`13°42' Libra`	Position as degrees and minutes, such as 11°39' Cancer
`midheaven`	object	`{…}`	The midheaven (MC), in the same shape as ascendant
`midheaven.sign`	string	`Cancer`	Sign of the midheaven
`midheaven.degree`	number	`15.92`	Degree within the sign (0-30)
`midheaven.longitude`	number	`105.9221`	Ecliptic longitude (0-360)
`midheaven.formatted`	string	`15°55' Cancer`	Position as degrees and minutes
`planets`	array[11]		The sun, moon, eight planets and the mean north node
`planets.0.name`	string	`Sun`	Body name
`planets.0.sign`	string	`Gemini`	Zodiac sign
`planets.0.degree`	number	`24.39`	Degree within the sign (0-30)
`planets.0.longitude`	number	`84.3882`	Tropical ecliptic longitude (0-360)
`planets.0.formatted`	string	`24°23' Gemini`	Position as degrees and minutes, such as 23°30' Pisces
`planets.0.house`Premium	number	`9`	The house (1-12) the body falls in
`planets.0.retrograde`	boolean	`false`	True when the body is in apparent backward motion
`planets.0.speed`	number	`0.9551`	Daily motion in degrees of longitude (negative when retrograde)
`houses`Premium	array[12]		The 12 house cusps in the chosen house system
`houses.0.house`Premium	number	`1`	House number (1-12)
`houses.0.sign`Premium	string	`Libra`	Sign on the cusp
`houses.0.degree`Premium	number	`13.7`	Degree of the cusp within the sign
`houses.0.longitude`Premium	number	`193.6954`	Ecliptic longitude of the cusp
`houses.0.formatted`Premium	string	`13°42' Libra`	Cusp position as degrees and minutes
`aspects`Premium	array[22]		Major aspects between bodies, tightest orb first
`aspects.0.planet1`Premium	string	`Moon`	First body
`aspects.0.planet2`Premium	string	`Venus`	Second body
`aspects.0.aspect`Premium	string	`sextile`	conjunction, opposition, trine, square or sextile
`aspects.0.angle`Premium	number	`60`	The exact angle of the aspect
`aspects.0.orb`Premium	number	`0.11`	Degrees away from exact
`aspects.0.applying`Premium	boolean	`true`	True when the aspect is moving toward exact
`elements`Premium	object	`{…}`	Count of the ten planets in fire, earth, air and water signs
`elements.fire`Premium	number	`1`
`elements.earth`Premium	number	`4`
`elements.air`Premium	number	`2`
`elements.water`Premium	number	`3`
`modalities`Premium	object	`{…}`	Count of the ten planets in cardinal, fixed and mutable signs
`modalities.cardinal`Premium	number	`5`
`modalities.fixed`Premium	number	`2`
`modalities.mutable`Premium	number	`3`

Failure modes

Errors come back as tool errors carrying a sentence the model can act on, not a bare status code. Error handling covers the full list.

Status	What it means
`400` / `422`	The arguments did not validate. The message names the offending one.
`401`	The OAuth session is invalid or expired — reconnect the server.
`403`	Blocked by a key restriction or an IP allow-list. Never a bad identity.
`404`	This skill is not part of VerveKit. Check the catalog.
`429`	Out of credits, or a brief rate limit. The message tells them apart.

A call costs 5 credits each time the tool actually runs; a model that reasons about the tool without calling it costs nothing.

Use cases

Astrology Apps: Generate a user's natal chart at sign-up from their birth details, and show the sun, moon and rising signs on their profile.
Compatibility Features: Calculate two charts and compare planet signs, elements and aspects to power a compatibility or matching feature.
Personalised Content: Pick daily content, readings or product recommendations by the user's rising sign, moon sign or dominant element.
Chart Rendering: Feed planet longitudes, house cusps and aspects into a chart wheel drawn in your own app.

Other ways to use Birth Chart

Set up Birth Chart on VerveKit, or reach the same source a different way. Your VerveKit account and credits work on all of them — one key, one balance.

Call it as a REST APIOne HTTPS endpoint and an x-api-key header, with SDKs for Node, Python and .NET.APIVerve →Reference →

Google Sheets or ExcelA =VERVE() formula fills a column — no script, no export, recalculates in place.VerveSheets →Reference →

Ground an agent on itA cited, machine-checkable fact your model can't produce on its own.VerveContext →Reference →