---
title: "Preflight every supported house system without fallback"
method: POST
path: "/api/astro/house-system-readiness"
tags: ["Calculations"]
---

# Preflight every supported house system without fallback

`POST /api/astro/house-system-readiness`

## Request

- Base URL: `https://api.cosmicephemeris.com`
- URL: `https://api.cosmicephemeris.com/api/astro/house-system-readiness`
- Auth: one of:
  - HTTP bearer
  - API key in header `x-api-key`

Evaluates Cosmic Ephemeris's fixed 25-system house inventory for one exact birth geometry. Each system is reported as available or unavailable; successful cusp sets receive a deterministic fingerprint and geometrically undefined systems remain explicit failures. The route never substitutes a different house system, returns interpretations, or makes request-time network calls. One standard quota unit per admitted request; failed or timed-out admitted attempts are not refunded. Do not automatically retry.
Historical mode uses an explicit BCE/CE date object and UT1 conventions. Its response is the versioned historical envelope, not the modern UTC envelope. Read result for calculation fields and metadata for limits and uncertainty.

## Headers

- `X-Cosmic-Ephemeris-Receipt` 'v1'

## Request body

- union
  - HouseSystemReadinessRequest
    - `birth` HouseSystemReadinessBirth, required
      - `date` string, date, required: Valid Gregorian YYYY-MM-DD local civil date, inclusive 1800-01-01 through 2200-12-31. Calendar validity and timezone conversion are checked by the server.
      - `time` string, required: HH:MM or HH:MM:SS; no offset in this field. Use timezone to select the civil-time zone.
      - `timezone` string, required
      - `lat` number, required
      - `lon` number, required
    - `profile` union, required
      - object
        - `zodiac` 'tropical', required
      - object
        - `zodiac` 'sidereal', required
        - `ayanamsa` 'lahiri' | 'raman' | 'krishnamurti' | 'fagan_bradley' | 'yukteshwar' | 'sassanian' | 'true_chitra' | 'true_revati' | 'true_pushya' | 'galactic_center_0_sagittarius' | 'galactic_alignment_mardyks', required
  - HistoricalHouseSystemReadinessRequest: Explicit historical mode, 1000 BCE (BC)–2500 CE (AD). No year zero, implicit calendar, UTC or IANA zone. Preserve tool-specific mathematical, geographic and search limits; calendar/time conventions and estimated Delta-T are not certified historical accuracy.
    - `birth` HistoricalBirthInput, required
      - `date` HistoricalDate, required: Explicit civil date, 1000 BCE (BC)–2500 CE (AD); no year zero. Calendar validity is checked by the server. Available only on documented connected historical operations, with explicit UT1/fixed-offset conventions.
        - `year` integer, required
        - `era` 'BCE' | 'CE', required: Display BCE (BC) / CE (AD); API values remain BCE / CE. No year zero.
        - `month` integer, required
        - `day` integer, required
        - `calendar` 'proleptic_gregorian' | 'proleptic_julian', required: Explicit choice; applies the selected calendar rules throughout history without a regional adoption switch.
      - `time` string, required: Explicit HH:MM[:SS]; whole seconds only, no leap seconds. Normalized helper output includes seconds.
      - `timezone` string, required: Explicit UT1 or fixed offset UT1+/-HH:MM[:SS], within 14 hours. Local clock minus offset yields UT1, not UTC. No IANA timezone inference. Original offset spelling is preserved.
      - `lat` number, required
      - `lon` number, required
    - `profile` union, required
      - object
        - `zodiac` 'tropical', required
      - object
        - `zodiac` 'sidereal', required
        - `ayanamsa` 'lahiri' | 'raman' | 'krishnamurti' | 'fagan_bradley' | 'yukteshwar' | 'sassanian' | 'true_chitra' | 'true_revati' | 'true_pushya' | 'galactic_center_0_sagittarius' | 'galactic_alignment_mardyks', required

## Response `200`

Fixed-inventory availability matrix with no substitution

- union
  - HouseSystemReadinessResponse
    - `type` 'house_system_readiness', required
    - `status` 'current', required
    - `input` object, required
      - `date` string, date, required: Valid Gregorian YYYY-MM-DD local civil date, inclusive 1800-01-01 through 2200-12-31. Calendar validity and timezone conversion are checked by the server.
      - `time` string, required: HH:MM or HH:MM:SS; no offset in this field. Use timezone to select the civil-time zone.
      - `timezone` string, required
      - `lat` number, required
      - `lon` number, required
    - `profile` object, required
      - `zodiac` 'tropical' | 'sidereal', required
      - `ayanamsa` 'lahiri' | 'raman' | 'krishnamurti' | 'fagan_bradley' | 'yukteshwar' | 'sassanian' | 'true_chitra' | 'true_revati' | 'true_pushya' | 'galactic_center_0_sagittarius' | 'galactic_alignment_mardyks', required
    - `systems` HouseSystemReadinessItem[], required
      - `id` 'equal' | 'whole_sign' | 'placidus' | 'porphyry' | 'meridian' | 'campanus' | 'regiomontanus' | 'alcabitius' | 'koch' | 'morinus' | 'topocentric' | 'sripati' | 'vehlow' | 'horizon' | 'krusinski' | 'sunshine' | 'sunshine_alt' | 'savard' | 'pullen_sd' | 'pullen_sr' | 'carter' | 'apc' | 'equal_mc' | 'natural' | 'gauquelin', required
      - `name` string, required
      - `status` 'available' | 'unavailable', required
      - `sector_count` 12 | 36, required
      - `cusps_sha256` string, nullable, required
      - `houses_route_ready` boolean, required
      - `natal_svg_route_ready` boolean, required
      - `reason_code` 'undefined_for_input_geometry', nullable, required
    - `summary` object, required
      - `system_count` 25, required
      - `available_count` integer, required
      - `unavailable_count` integer, required
      - `houses_route_ready_count` integer, required
      - `natal_svg_route_ready_count` integer, required
    - `fallback` object, required
      - `performed` unknown, required
      - `selected_system` unknown, required
    - `metadata` object, required
    - `receipt` CalculationReceipt
      - `schema` 'cosmicephemeris-calculation-receipt-v1', required
      - `kid` string, required
      - `algorithm` 'Ed25519', required
      - `canonicalization` 'cosmicephemeris-canonical-data-v1', required
      - `input_normalization` 'public-request-canonical-data-v1', required
      - `route` string, required
      - `release` string, required
      - `issued_at` string, date-time, required
      - `normalized_input_sha256` string, required
      - `result_sha256` string, required
      - `calculation_profile` object, required
      - `service_dataset_versions` object, required
      - `calculation_fingerprint` string, required
      - `verification_uri` string, required
      - `signature` string, required
  - HistoricalHouseSystemReadinessHouseSystemReadinessResponse
    - `schema` 'cosmicephemeris-historical-calculation-v1', required
    - `status` 'historical', required
    - `type` 'house-system-readiness', required
    - `input` HistoricalHouseSystemReadinessRequest, required: Explicit historical mode, 1000 BCE (BC)–2500 CE (AD). No year zero, implicit calendar, UTC or IANA zone. Preserve tool-specific mathematical, geographic and search limits; calendar/time conventions and estimated Delta-T are not certified historical accuracy.
      - `birth` HistoricalBirthInput, required
        - `date` HistoricalDate, required: Explicit civil date, 1000 BCE (BC)–2500 CE (AD); no year zero. Calendar validity is checked by the server. Available only on documented connected historical operations, with explicit UT1/fixed-offset conventions.
          - `year` integer, required
          - `era` 'BCE' | 'CE', required: Display BCE (BC) / CE (AD); API values remain BCE / CE. No year zero.
          - `month` integer, required
          - `day` integer, required
          - `calendar` 'proleptic_gregorian' | 'proleptic_julian', required: Explicit choice; applies the selected calendar rules throughout history without a regional adoption switch.
        - `time` string, required: Explicit HH:MM[:SS]; whole seconds only, no leap seconds. Normalized helper output includes seconds.
        - `timezone` string, required: Explicit UT1 or fixed offset UT1+/-HH:MM[:SS], within 14 hours. Local clock minus offset yields UT1, not UTC. No IANA timezone inference. Original offset spelling is preserved.
        - `lat` number, required
        - `lon` number, required
      - `profile` union, required
        - object
          - `zodiac` 'tropical', required
        - object
          - `zodiac` 'sidereal', required
          - `ayanamsa` 'lahiri' | 'raman' | 'krishnamurti' | 'fagan_bradley' | 'yukteshwar' | 'sassanian' | 'true_chitra' | 'true_revati' | 'true_pushya' | 'galactic_center_0_sagittarius' | 'galactic_alignment_mardyks', required
    - `result` object, required: Complete historical calculation adapter result. Times are explicit UT1 date records, never UTC strings; derived times may include fractional seconds and years outside the input range.
    - `metadata` object, required
      - `time_standard` 'UT1', required
      - `historical_accuracy_certified` unknown, required
      - `warnings` string[], required

## Other responses

- `400`: Invalid request, malformed JSON, out-of-range date/location, unknown model, invalid timezone or ambiguous/nonexistent clock-change time. Invalid attempts reaching quota reservation consume one unit.
- `401`: Missing, invalid, revoked API key or unavailable activated key owner. Dashboard cookies do not authenticate calculation routes.
- `403`: Origin not allowed by production CORS policy. Server-to-server requests can omit Origin.
- `429`: Monthly quota exhausted, per-user two-request concurrency reached, or nginx rate/connection admission refused. Retry-After: 2 is sent for application per-user concurrency only, not a promise that monthly quota resets in two seconds.
- `502`: Engine unavailable, unsuccessful internal server response or invalid upstream JSON. No engine internals are exposed.
- `503`: Four-request global calculation pool full (Retry-After: 2), maintenance or upstream service unavailable.
- `504`: Application engine timeout: 15 seconds normally; planetary events, house ingresses, aspect windows, event calendar, eclipse geometry, electional search, and event-rule search use 30 seconds; Nakshatra Timeline plus the explicitly enumerated readiness, robustness, location, uncertainty, and electional-audit family use 60 seconds. Timer includes response-body parsing; an admitted timeout consumes quota.

---

[API](https://skmtc.dev/cosmicephemeris/apis/cosmic-ephemeris-calculation-api.md) · [All operations](https://skmtc.dev/cosmicephemeris/apis/cosmic-ephemeris-calculation-api/llms.txt) · [OpenAPI document](https://skmtc.dev/cosmicephemeris/apis/cosmic-ephemeris-calculation-api/revisions/f041e924cea3?raw)