Monthly Forecast

POST

/bazi/monthly

request.sh

curl -X POST https://api.astroway.info/v1/bazi/monthly \
  -H "X-Api-Key: aw_live_..." \
  -H "Content-Type: application/json" \
  -d '{ "natalDate": "1990-05-15", "targetYear": 2026, "targetMonth": 6 }'

▸ Try it POST /bazi/monthly

• Production

Same Sheng-Ke + branch-clash analysis as yearly, but applied to a specific calendar month. Month branch resolved via mid-month jieqi.

Authorizations

• ApiKeyAuth

Parameters

Query Parameters

fields

string

Comma-separated dotted paths, relative to data, to keep in the response. A path is applied to every element of an array, so planets.name means the name of each planet. Paths that match nothing come back in _fields_unmatched; a list where nothing matches at all is a 400, because an empty object would be a confident wrong answer.

Example

planets.name,planets.longitude

precision

integer

<= 15

Round every non-integer number in the response to this many decimal places. Integers are left alone, because an id is not a measurement. Ecliptic longitudes ship with fourteen decimals by default; 2 is about a tenth of an arcminute.

Example

4

Header Parameters

Idempotency-Key

string

>= 1 characters <= 255 characters /^[\x21-\x7E]+$/

Unique per logical operation, kept across retries. For 24 hours from the first request, a repeat with the same key, method, path, body and query string returns the stored response with Idempotent-Replayed: true and costs 0 credits. The same key with a different body or query string is a 409 IDEMPOTENCY_KEY_REUSED; a repeat while the first is still running is a 409 IDEMPOTENCY_IN_PROGRESS. Only 2xx responses are kept. See /idempotency/.

Example

01HXY2A7ZM0ABCDEF

Request Body ^required

Media type application/json

object

natalDate required

string

/^\d{4}-\d{2}-\d{2}$/

natalTime

string

/^\d{2}:\d{2}(:\d{2})?$/

natalTzOffset

Ignored when timezone is sent.

number

>= -14 <= 14

timezone

IANA zone name such as Europe/Kyiv, or auto to look the zone up from latitude and longitude. The server takes the offset that zone kept at this local date and time, summer time included, and uses it in place of timezoneOffset. A clock time that happened twice takes the first occurrence; one skipped when clocks went forward takes the offset from before the change. Abbreviations such as EST are refused. Before 1970 the tz database is not reliable for every place, so send timezoneOffset when the local clock is known.

string

longitude

number

>= -180 <= 180

trueSolarTime

boolean

dayBoundary

string

Allowed values: 23:00 midnight

targetYear required

integer

>= 1900 <= 2100

targetMonth required

integer

>= 1 <= 12

language

string

Example

{
  "natalDate": "1990-05-15",
  "targetYear": 2026,
  "targetMonth": 6
}

Responses

200

Successful calculation

Media type application/json

object

ok

boolean

data

object

natalDayMaster

object

stem

string

nullable

element

string

nullable

yin

boolean

nullable

targetYear

number

nullable

targetMonth

number

nullable

targetPillar

object

stem

string

nullable

branch

string

nullable

pillar

string

nullable

animal

string

nullable

elementFlow

object

stem

object

element

string

nullable

relation

string

nullable

flavor

string

nullable

branch

object

element

string

nullable

relation

string

nullable

flavor

string

nullable

branchInteractions

object

clashes

Array

nullable

notes

Array<string>

nullable

disclaimer

string

nullable

Example

{
  "ok": true,
  "data": {
    "natalDayMaster": {
      "stem": "Geng",
      "element": "Metal",
      "yin": false
    },
    "targetYear": 2026,
    "targetMonth": 6,
    "targetPillar": {
      "stem": "Jia",
      "branch": "Wu",
      "pillar": "Jia-Wu",
      "animal": "Horse"
    },
    "elementFlow": {
      "stem": {
        "element": "Wood",
        "relation": "wealth",
        "flavor": "wealth (财): material gain or expense year"
      },
      "branch": {
        "element": "Fire",
        "relation": "control",
        "flavor": "control / officer (官杀): pressure or authority year"
      }
    },
    "branchInteractions": {
      "clashes": []
    },
    "notes": [
      "Month branch determined by jieqi at mid-month (~15th). For exact day boundaries, pair with /v1/sun-times."
    ],
    "disclaimer": "BaZi pillars use the canonical 60-jiazi cycle, anchored at 1990-01-01 = Bing-Yin. Year and month boundaries are the exact Lichun and 節 instants from the ephemeris, stated in China Standard Time; pass time and timezoneOffset for births near a boundary. Day and hour follow the birthplace clock, with the day rolling at 23:00 local."
  }
}

400

Validation error

Media type application/json

Example

{
  "ok": false,
  "error": {
    "code": "INVALID_INPUT",
    "message": "Validation failed: date: Date must be YYYY-MM-DD",
    "details": [
      {
        "path": "date",
        "message": "Date must be YYYY-MM-DD"
      }
    ]
  }
}

401

Missing or invalid API key

Media type application/json

Example

{
  "ok": false,
  "error": {
    "code": "INVALID_API_KEY",
    "message": "Invalid API key"
  }
}