Skip to main content
Glama

Western Astrology MCP Server by RoxyAPI

Composite Chart - Midpoint relationship chart with interpretations

post_astrology_composite_chart
Read-only

Generate a composite chart by calculating midpoints between two natal charts. The composite chart represents the relationship as a single entity, showing its core identity, emotional bond, communication style, and growth direction. Uses the midpoint method: planets, angles and house cusps are each the midpoint of the two natal values, so the Ascendant always sits on the first cusp. Returns composite planetary positions, house cusps, Ascendant, Midheaven, aspects, and relationship interpretation. Composite chart API, midpoint chart calculator, relationship astrology, couple chart analysis.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
langNoResponse language (BCP 47). Supported: en, tr, de, es, hi, pt, fr, ru, zh-Hans, zh-Hant. Defaults to en. Coverage varies by domain, and a field with no translation in the requested language returns English.en
compactNoSet true for the same data in a compact shape: arrays of same-shaped objects arrive columnar as {"__cols":[names],"__rows":[[values]]}. Lossless, typically 40 to 52 percent fewer tokens.
person1YesFirst person birth details (date, time, location, timezone).
person2YesSecond person birth details (date, time, location, timezone).
houseSystemNoHouse system for the composite chart. Placidus (default), Whole Sign, Equal, or Koch.placidus

Schema Changelog

Changes observed during successful MCP inspections. Dates show when Glama detected each change.

  1. Changed2 schema fields changed
    • changedInput schema / properties / lang / description
      Previous value: -"Response language (ISO 639-1). Supported: en, tr, de, es, hi, pt, fr, ru. Defaults to en. Languages without translations yet return English."New value: +"Response language (BCP 47). Supported: en, tr, de, es, hi, pt, fr, ru, zh-Hans, zh-Hant. Defaults to en. Coverage varies by domain, and a field with no translation in the requested language returns English."
    • changedInput schema / properties / lang / enum
      Previous value: -[
      -  "en",
      -  "tr",
      -  "de",
      -  "es",
      -  "hi",
      -  "pt",
      -  "fr",
      -  "ru"
      -]New value: +[
      +  "en",
      +  "tr",
      +  "de",
      +  "es",
      +  "hi",
      +  "pt",
      +  "fr",
      +  "ru",
      +  "zh-Hans",
      +  "zh-Hant"
      +]
  2. Changed4 schema fields changed
    • addedInput schema / examples
      Added value: +[
      +  {
      +    "person1": {
      +      "date": "1990-07-15",
      +      "latitude": 40.7128,
      +      "longitude": -74.006,
      +      "time": "14:30:00",
      +      "timezone": -5
      +    },
      +    "person2": {
      +      "date": "1990-07-15",
      +      "latitude": 40.7128,
      +      "longitude": -74.006,
      +      "time": "14:30:00",
      +      "timezone": -5
      +    }
      +  }
      +]
    • changedInput schema / properties / compact / description
      Previous value: -"Set true to receive the exact same data in a token-optimized shape that is cheaper for you to read: whitespace is stripped and every array of same-shaped objects is encoded columnar as {\"__cols\":[field names],\"__rows\":[[values]]}, so each field name is sent once instead of once per row. Fully lossless (no field or value is dropped or changed) and typically 40 to 52 percent fewer tokens on large results. Prefer true whenever token or inference cost matters. Default false returns standard indented JSON."New value: +"Set true for the same data in a compact shape: arrays of same-shaped objects arrive columnar as {\"__cols\":[names],\"__rows\":[[values]]}. Lossless, typically 40 to 52 percent fewer tokens."
    • changedInput schema / properties / person1 / properties / nodeType / description
      Previous value: -"Lunar node convention. \"mean\" is the smoothed average node, which always moves retrograde; \"true\" is the osculating node, which tracks the real perturbed node, oscillates up to about 1.5 degrees either side of the mean on a 173-day cycle, and can briefly turn direct. Neither is more correct and they almost always fall in the same sign. Applies to the North and South Node. True is what most Western software reports (Astrolabe, Cafe Astrology, TimePassages), which is why it is the default here; astro-seek and the Steven Forrest evolutionary school use mean, so pass \"mean\" to match those. Nothing else in the chart changes, and the two agree on the sign except when the node sits within about 1.8 degrees of a cusp. Defaults to \"true\"."New value: +"Lunar node convention. \"mean\" is the smoothed average node, which always moves retrograde; \"true\" is the osculating node, which tracks the real perturbed node, oscillates up to about 1.5 degrees either side of the mean on a 173-day cycle, and can briefly turn direct. Neither is more correct and they almost always fall in the same sign. Applies to the North and South Node. True is the osculating node and the default, because it is what most Western chart software reports; mean is the smoothed node preferred by several evolutionary schools, so pass \"mean\" to match one. Nothing else in the chart changes, and the two agree on the sign except when the node sits within about 1.8 degrees of a cusp. Defaults to \"true\"."
    • changedInput schema / properties / person2 / properties / nodeType / description
      Previous value: -"Lunar node convention. \"mean\" is the smoothed average node, which always moves retrograde; \"true\" is the osculating node, which tracks the real perturbed node, oscillates up to about 1.5 degrees either side of the mean on a 173-day cycle, and can briefly turn direct. Neither is more correct and they almost always fall in the same sign. Applies to the North and South Node. True is what most Western software reports (Astrolabe, Cafe Astrology, TimePassages), which is why it is the default here; astro-seek and the Steven Forrest evolutionary school use mean, so pass \"mean\" to match those. Nothing else in the chart changes, and the two agree on the sign except when the node sits within about 1.8 degrees of a cusp. Defaults to \"true\"."New value: +"Lunar node convention. \"mean\" is the smoothed average node, which always moves retrograde; \"true\" is the osculating node, which tracks the real perturbed node, oscillates up to about 1.5 degrees either side of the mean on a 173-day cycle, and can briefly turn direct. Neither is more correct and they almost always fall in the same sign. Applies to the North and South Node. True is the osculating node and the default, because it is what most Western chart software reports; mean is the smoothed node preferred by several evolutionary schools, so pass \"mean\" to match one. Nothing else in the chart changes, and the two agree on the sign except when the node sits within about 1.8 degrees of a cusp. Defaults to \"true\"."
  3. Changed2 schema fields changed
    • addedInput schema / properties / person1 / properties / nodeType
      Added value: +{
      +  "default": "true",
      +  "description": "Lunar node convention. \"mean\" is the smoothed average node, which always moves retrograde; \"true\" is the osculating node, which tracks the real perturbed node, oscillates up to about 1.5 degrees either side of the mean on a 173-day cycle, and can briefly turn direct. Neither is more correct and they almost always fall in the same sign. Applies to the North and South Node. True is what most Western software reports (Astrolabe, Cafe Astrology, TimePassages), which is why it is the default here; astro-seek and the Steven Forrest evolutionary school use mean, so pass \"mean\" to match those. Nothing else in the chart changes, and the two agree on the sign except when the node sits within about 1.8 degrees of a cusp. Defaults to \"true\".",
      +  "enum": [
      +    "mean",
      +    "true"
      +  ],
      +  "example": "true",
      +  "type": "string"
      +}
    • addedInput schema / properties / person2 / properties / nodeType
      Added value: +{
      +  "default": "true",
      +  "description": "Lunar node convention. \"mean\" is the smoothed average node, which always moves retrograde; \"true\" is the osculating node, which tracks the real perturbed node, oscillates up to about 1.5 degrees either side of the mean on a 173-day cycle, and can briefly turn direct. Neither is more correct and they almost always fall in the same sign. Applies to the North and South Node. True is what most Western software reports (Astrolabe, Cafe Astrology, TimePassages), which is why it is the default here; astro-seek and the Steven Forrest evolutionary school use mean, so pass \"mean\" to match those. Nothing else in the chart changes, and the two agree on the sign except when the node sits within about 1.8 degrees of a cusp. Defaults to \"true\".",
      +  "enum": [
      +    "mean",
      +    "true"
      +  ],
      +  "example": "true",
      +  "type": "string"
      +}
  4. Changed1 schema field changed
    • changedInput schema / properties / compact / description
      Previous value: -"Return the same data in a token-optimized compact shape (minified, with same-shaped arrays encoded columnar) to reduce LLM token cost. Lossless: no fields are dropped. Default false."New value: +"Set true to receive the exact same data in a token-optimized shape that is cheaper for you to read: whitespace is stripped and every array of same-shaped objects is encoded columnar as {\"__cols\":[field names],\"__rows\":[[values]]}, so each field name is sent once instead of once per row. Fully lossless (no field or value is dropped or changed) and typically 40 to 52 percent fewer tokens on large results. Prefer true whenever token or inference cost matters. Default false returns standard indented JSON."
  5. Changed1 schema field changed
    • addedInput schema / properties / compact
      Added value: +{
      +  "default": false,
      +  "description": "Return the same data in a token-optimized compact shape (minified, with same-shaped arrays encoded columnar) to reduce LLM token cost. Lossless: no fields are dropped. Default false.",
      +  "type": "boolean"
      +}
  6. Changed4 schema fields changed
    • changedInput schema / properties / person1 / properties / timezone / anyOf
      Previous value: -[
      -  {
      -    "maximum": 14,
      -    "minimum": -14,
      -    "type": "number"
      -  },
      -  {
      -    "pattern": "^[A-Za-z_]+(?:\\/[A-Za-z0-9_+-]+){0,2}$",
      -    "type": "string"
      -  }
      -]New value: +[
      +  {
      +    "maximum": 14,
      +    "minimum": -14,
      +    "type": "number"
      +  },
      +  {
      +    "type": "string"
      +  }
      +]
    • changedInput schema / properties / person1 / properties / timezone / description
      Previous value: -"Timezone: decimal hours from UTC (e.g. -5 for EST, 5.5 for IST) OR IANA name (e.g. \"America/New_York\", \"Asia/Kolkata\"). IANA strings are resolved to the DST-correct offset for the given date, so you can pass `cities[0].timezone` from /location/search directly."New value: +"Timezone: IANA name (e.g. \"America/New_York\", \"Europe/London\") OR decimal hours from UTC (e.g. -5 for EST, 1 for CET). IANA strings are resolved to the DST-correct offset for the given date, so you can pass `cities[0].timezone` from /location/search directly."
    • changedInput schema / properties / person2 / properties / timezone / anyOf
      Previous value: -[
      -  {
      -    "maximum": 14,
      -    "minimum": -14,
      -    "type": "number"
      -  },
      -  {
      -    "pattern": "^[A-Za-z_]+(?:\\/[A-Za-z0-9_+-]+){0,2}$",
      -    "type": "string"
      -  }
      -]New value: +[
      +  {
      +    "maximum": 14,
      +    "minimum": -14,
      +    "type": "number"
      +  },
      +  {
      +    "type": "string"
      +  }
      +]
    • changedInput schema / properties / person2 / properties / timezone / description
      Previous value: -"Timezone: decimal hours from UTC (e.g. -5 for EST, 5.5 for IST) OR IANA name (e.g. \"America/New_York\", \"Asia/Kolkata\"). IANA strings are resolved to the DST-correct offset for the given date, so you can pass `cities[0].timezone` from /location/search directly."New value: +"Timezone: IANA name (e.g. \"America/New_York\", \"Europe/London\") OR decimal hours from UTC (e.g. -5 for EST, 1 for CET). IANA strings are resolved to the DST-correct offset for the given date, so you can pass `cities[0].timezone` from /location/search directly."
  7. First observed

TDQS

A4/5.0
Behavior4/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already convey read-only, non-destructive behavior, so the description only needed to add behavioral context. It does so by specifying that all chart points are computed as midpoints and by stating the invariant that the Ascendant sits on the first cusp, which usefully signals the exact calculation approach.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness3/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The first several sentences earn their place by explaining the method, result, and return contents. However, the final sentence is a loose keyword list ('Composite chart API, midpoint relationship calculator, relationship astrology, couple chart analysis') that adds no functional guidance for an agent and slightly dilutes an otherwise clear description.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The description lists the principal returned components: planetary positions, house cusps, Ascendant, Midheaven, aspects, and relationship interpretation. Since no output schema exists, this return summary is valuable. Combined with the rich parameter schema and read-only annotations, an agent has sufficient context to select and invoke the tool.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, and every parameter already has a rich description including defaults, formats, and examples. The tool description adds little parameter-level detail beyond referring generally to two natal charts and the midpoint method, so it does not significantly exceed what the schema already provides.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states a specific action ('Generate') on a specific resource ('composite chart') and gives the midpoint method. It also distinguishes this tool from synastry/compatibility siblings by emphasizing that the composite chart represents the relationship as a single entity rather than comparing two charts.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description gives clear context for when to use the tool: whenever a midpoint-based relationship chart is needed. It does not explicitly name alternatives or say 'use this instead of synastry', so it falls short of full routing guidance, but the semantic distinction between relationship-as-a-single-entity and other relationship chart types is effectively implied.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Try in Browser

Glama MCP Gateway

Add one secure layer between your agents and this server.

TDQS

A3.8/5.0
Disambiguation3/5

Most tools are scoped to a clearly distinct domain—moon phases, houses, returns, fixed stars, astrocartography—but several pairs overlap, notably synastry vs. compatibility_score and transits vs. transit_aspects. The descriptions are long and do help an agent choose, but the boundaries are not always obvious at the name level.

Naming Consistency4/5

Every tool follows the same snake_case get_astrology_/post_astrology_ prefix pattern, making the group predictable and readable. However, collection endpoints like get_astrology_planet_meanings_id and get_astrology_signs_id awkwardly combine plural collection and singular id naming, and names like calendar_year_month depart from the cleaner resource+suffix pattern.

Tool Count2/5

With 38 tools, this is well over the 25+ threshold and feels heavy for an agent to traverse. While Western astrology is a broad domain, several near-duplicate endpoints, especially synastry/compatibility and transits/transit_aspects, could be consolidated into fewer, more scoped tools.

Completeness5/5

The toolset is comprehensive, covering natal charts, relationships, transits, returns, progressions, aspects, houses, relocation, and reference data. It includes enough specialized endpoints for both casual horoscope use and in-depth astrological analysis, with no obvious dead ends for the stated domain.

Resources