---
title: "Audit chart sensitivity to birth-coordinate precision"
method: POST
path: "/api/astro/location-precision-audit"
tags: ["Calculations"]
---

# Audit chart sensitivity to birth-coordinate precision

`POST /api/astro/location-precision-audit`

## Request

- Base URL: `https://api.cosmicephemeris.com`
- URL: `https://api.cosmicephemeris.com/api/astro/location-precision-audit`
- Auth: one of:
  - HTTP bearer
  - API key in header `x-api-key`

Calculates one exact birth moment at the supplied coordinates and eight equally spaced bearings on a caller-declared spherical radius. It reports selected-planet house stability, explicit per-sample geometry failures, and maximum Ascendant, Midheaven, and cusp displacement from the center for one selected 12-house system. The nine samples describe only the center and perimeter points; they are not statistical confidence, do not guarantee every point inside the disk, and do not rank locations, rectify birth data, interpret a chart, or make predictions. Gauquelin is excluded because it is a 36-sector system. 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
  - LocationPrecisionAuditRequest
    - `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
        - `house_system` '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', 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
        - `house_system` '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', required
    - `radius_km` number, required
    - `points` LocationPrecisionAuditPoint[]
  - HistoricalLocationPrecisionAuditRequest: 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
        - `house_system` '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', 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
        - `house_system` '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', required
    - `radius_km` number, required
    - `points` string[]

## Response `200`

Bounded coordinate-precision sensitivity audit

- union
  - LocationPrecisionAuditResponse
    - `type` 'location_precision_audit', required
    - `status` 'current', required
    - `input` object, required
      - `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
          - `house_system` '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', 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
          - `house_system` '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', required
      - `radius_km` number, required
      - `points` LocationPrecisionAuditPoint[], required
    - `samples` LocationPrecisionAuditSample[], required
      - `id` 'center' | 'north' | 'northeast' | 'east' | 'southeast' | 'south' | 'southwest' | 'west' | 'northwest', required
      - `bearing_degrees` number, nullable, required
      - `distance_km` number, required
      - `lat` number, required
      - `lon` number, required
      - `status` 'available' | 'unavailable', required
      - `reason_code` 'undefined_for_input_geometry', nullable, required
      - `ascendant` number, nullable, required
      - `mc` number, nullable, required
      - `cusps` Cusps, required
        - `1` number, required
        - `2` number, required
        - `3` number, required
        - `4` number, required
        - `5` number, required
        - `6` number, required
        - `7` number, required
        - `8` number, required
        - `9` number, required
        - `10` number, required
        - `11` number, required
        - `12` number, required
      - `placements` LocationPrecisionAuditPlacements, required
        - `sun` LocationPrecisionAuditPlacement
          - `longitude` number, required
          - `house` integer, required
        - `moon` LocationPrecisionAuditPlacement
          - `longitude` number, required
          - `house` integer, required
        - `mercury` LocationPrecisionAuditPlacement
          - `longitude` number, required
          - `house` integer, required
        - `venus` LocationPrecisionAuditPlacement
          - `longitude` number, required
          - `house` integer, required
        - `mars` LocationPrecisionAuditPlacement
          - `longitude` number, required
          - `house` integer, required
        - `jupiter` LocationPrecisionAuditPlacement
          - `longitude` number, required
          - `house` integer, required
        - `saturn` LocationPrecisionAuditPlacement
          - `longitude` number, required
          - `house` integer, required
        - `uranus` LocationPrecisionAuditPlacement
          - `longitude` number, required
          - `house` integer, required
        - `neptune` LocationPrecisionAuditPlacement
          - `longitude` number, required
          - `house` integer, required
        - `pluto` LocationPrecisionAuditPlacement
          - `longitude` number, required
          - `house` integer, required
    - `point_summaries` LocationPrecisionAuditPointSummary[], required
      - `name` 'sun' | 'moon' | 'mercury' | 'venus' | 'mars' | 'jupiter' | 'saturn' | 'uranus' | 'neptune' | 'pluto', required
      - `center_longitude` number, nullable, required
      - `center_house` integer, nullable, required
      - `evaluable` boolean, required
      - `available_sample_count` integer, required
      - `unavailable_sample_count` integer, required
      - `stable_across_available_samples` boolean, required
      - `observed_houses` integer[], required
      - `assignments` LocationPrecisionAuditAssignment[], required
        - `house` integer, required
        - `sample_count` integer, required
        - `sample_ids` string[], required
    - `angle_summaries` object, required
      - `ascendant` LocationPrecisionAuditShiftSummary, required
        - `center_longitude` number, nullable, required
        - `maximum_absolute_shift_degrees` number, nullable, required
        - `maximum_shift_sample_ids` string[], required
      - `midheaven` LocationPrecisionAuditShiftSummary, required
        - `center_longitude` number, nullable, required
        - `maximum_absolute_shift_degrees` number, nullable, required
        - `maximum_shift_sample_ids` string[], required
    - `cusp_summaries` LocationPrecisionAuditCuspSummary[], required
      - `house` integer, required
      - `center_longitude` number, nullable, required
      - `maximum_absolute_shift_degrees` number, nullable, required
      - `maximum_shift_sample_ids` string[], required
    - `summary` object, required
      - `sample_count` 9, required
      - `available_sample_count` integer, required
      - `unavailable_sample_count` integer, required
      - `center_available` boolean, required
      - `point_count` integer, required
      - `stable_point_count` integer, required
      - `sensitive_point_count` integer, required
    - `fallback` object, required
      - `performed` unknown, required
      - `selected_system` unknown, required
    - `metadata` object, required
      - `model` 'cosmicephemeris-location-precision-audit-v1', required
      - `house_system_name` string, required
      - `sampling_method` 'center_plus_eight_equal_bearings_on_spherical_radius', required
      - `earth_radius_km` 6371.0088, required
      - `perimeter_only` unknown, required
      - `entire_disk_guarantee` unknown, required
      - `statistical_confidence` unknown, required
      - `max_chart_evaluations` 9, required
      - `max_placement_evaluations` 90, required
      - `recommendations` unknown, required
      - `interpretations` unknown, required
      - `predictions` unknown, required
      - `request_time_network` unknown, 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
  - HistoricalLocationPrecisionAuditLocationPrecisionAuditResponse
    - `schema` 'cosmicephemeris-historical-calculation-v1', required
    - `status` 'historical', required
    - `type` 'location-precision-audit', required
    - `input` HistoricalLocationPrecisionAuditRequest, 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
          - `house_system` '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', 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
          - `house_system` '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', required
      - `radius_km` number, required
      - `points` string[]
    - `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)