Secondary Progressions

Endpoint POST https://starsapi.com/api/v3/western/forecasting/progressions

Overview

Computes the secondary progressed chart using the classical “day for a year” formula. For someone 36 years old, the progressed chart is calculated for 36 days after birth. Returns progressed planet positions, progressed angles (ASC/MC), and all aspects between progressed and natal planets.

The progressed Moon is the most watched body — it moves ~1° per month and changes sign every ~2.5 years, marking major emotional/life phase shifts.

Authentication

Method	Example
Header (recommended)	`X-Api-Key: sa_live_xxxxxxxxxxxx`
Bearer	`Authorization: Bearer sa_live_xxxxxxxxxxxx`

Request body

Field	Type	Required	Description
`year` – `minute`		Yes	Standard birth data fields.
`latitude`, `longitude`	number	Yes	Birth location.
`timezone`	string	Yes	IANA timezone.
`house_system`	string	No	Default `placidus`.
`node_type`	string	No	Default `true`.
`progression_year`	integer	No	Target year for progressions. Defaults to today (in birth timezone) if the three date fields are omitted.
`progression_month`	integer	No	Target month. Defaults to the current month.
`progression_day`	integer	No	Target day. Defaults to the current day.
`relocation_latitude`	number	No	Recast progressed angles & house cusps at this latitude. Default: birth latitude.
`relocation_longitude`	number	No	Recast progressed angles & house cusps at this longitude. Default: birth longitude.

Relocation

Progressed angles (ASC/MC) and house cusps are location-sensitive; by default they are cast at the birthplace. Pass relocation_latitude and relocation_longitude to recast the progressed Ascendant, Midheaven and house cusps at your current place — useful when the native has moved far from where they were born.

Progressed planet longitudes are unchanged by relocation (ecliptic longitude is location-independent), and the birth timezone is retained — only the angles and house cusps shift. Omit both fields for zero change (birthplace default, no breaking change to existing calls).

When relocation coordinates are supplied, the response meta block echoes relocated: true together with the relocation coordinates used; otherwise relocated: false and the birth coordinates are echoed.

Response shape

Field	Description
`natal_planets`	Original natal positions.
`progressed_planets`	Progressed positions at target date.
`progressed_ascendant`	Progressed rising sign (recast at relocation coords when supplied).
`progressed_midheaven`	Progressed MC (recast at relocation coords when supplied).
`progressed_aspects`	Progressed-to-natal aspects with orbs.
`progressed_date_info`	Calculation metadata (days of life, progressed days).
`target_date`	The target date used (`YYYY-MM-DD`) — requested date, or today if it defaulted.
`target_date_text`	Human-readable target date, e.g. `17 June 2026`.
`progression_date_source`	`provided` if the date was passed, or `current_date` if it defaulted to today.
`age_years`	Age (whole years) at the target date.
`progression_text`	Ready-to-display label, e.g. `Progressed chart for 17 June 2026 (age 36)`.
`meta.relocated`	Boolean — whether progressed angles/houses were recast away from the birthplace.
`meta.relocation`	The latitude/longitude used for the progressed angles and house cusps.

Errors

HTTP	Code	Cause
400	`MISSING_FIELD`	Required field absent. The `progression_year/month/day` fields are optional (default to today).
400	`INVALID_DATE`	Invalid progression target date.
400	`INVALID_COORDINATE`	`relocation_latitude` out of −90…90 or `relocation_longitude` out of −180…180.
500	`EPHEMERIS_ERROR`	Computation failed.

# Replace YOUR_API_KEY with the key from your dashboard
curl -X POST "https://starsapi.com/api/v3/western/forecasting/progressions" \
  -H "X-Api-Key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
        "year": 1990,
        "month": 5,
        "day": 20,
        "hour": 14,
        "minute": 30,
        "second": 0,
        "latitude": 28.6139,
        "longitude": 77.209,
        "timezone": "Asia/Kolkata",
        "house_system": "placidus",
        "node_type": "true",
        "progression_year": 2026,
        "progression_month": 6,
        "progression_day": 17
    }'

const response = await fetch(
  'https://starsapi.com/api/v3/western/forecasting/progressions',
  {
    method: 'POST',
    headers: {
      'X-Api-Key': 'YOUR_API_KEY',
      'Content-Type': 'application/json'
    },
    body: JSON.stringify({
      year: 1990,
      month: 5,
      day: 20,
      hour: 14,
      minute: 30,
      second: 0,
      latitude: 28.6139,
      longitude: 77.209,
      timezone: 'Asia/Kolkata',
      house_system: 'placidus',
      node_type: 'true',
      progression_year: 2026,
      progression_month: 6,
      progression_day: 17
    })
  }
);
const result = await response.json();

if (result.success) {
  console.log(result.data);
}

import requests
import os

response = requests.post(
    'https://starsapi.com/api/v3/western/forecasting/progressions',
    headers={'X-Api-Key': os.environ['STARSAPI_KEY']},
    json={
        'year': 1990,
        'month': 5,
        'day': 20,
        'hour': 14,
        'minute': 30,
        'second': 0,
        'latitude': 28.6139,
        'longitude': 77.209,
        'timezone': 'Asia/Kolkata',
        'house_system': 'placidus',
        'node_type': 'true',
        'progression_year': 2026,
        'progression_month': 6,
        'progression_day': 17
    }
)
result = response.json()

if result['success']:
    print(result['data'])

<?php
$payload = [
    'year' => 1990,
    'month' => 5,
    'day' => 20,
    'hour' => 14,
    'minute' => 30,
    'second' => 0,
    'latitude' => 28.6139,
    'longitude' => 77.209,
    'timezone' => 'Asia/Kolkata',
    'house_system' => 'placidus',
    'node_type' => 'true',
    'progression_year' => 2026,
    'progression_month' => 6,
    'progression_day' => 17,
];

$ch = curl_init('https://starsapi.com/api/v3/western/forecasting/progressions');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($payload));
curl_setopt($ch, CURLOPT_HTTPHEADER, [
    'X-Api-Key: ' . getenv('STARSAPI_KEY'),
    'Content-Type: application/json'
]);

$response = curl_exec($ch);
$data = json_decode($response, true);

if ($data['success']) {
    print_r($data['data']);
}

import 'package:http/http.dart' as http;
import 'dart:convert';

Future<Map<String, dynamic>> getAscendant() async {
  final response = await http.post(
    Uri.parse('https://starsapi.com/api/v3/western/forecasting/progressions'),
    headers: {
      'X-Api-Key': 'YOUR_API_KEY',
      'Content-Type': 'application/json',
    },
    body: jsonEncode({
      'year': 1990,
      'month': 5,
      'day': 20,
      'hour': 14,
      'minute': 30,
      'second': 0,
      'latitude': 28.6139,
      'longitude': 77.209,
      'timezone': 'Asia/Kolkata',
      'house_system': 'placidus',
      'node_type': 'true',
      'progression_year': 2026,
      'progression_month': 6,
      'progression_day': 17,
    }),
  );
  return jsonDecode(response.body);
}

import Foundation

func getAscendant() async throws -> [String: Any] {
    var request = URLRequest(url: URL(string:
        "https://starsapi.com/api/v3/western/forecasting/progressions"
    )!)
    request.httpMethod = "POST"
    request.setValue("YOUR_API_KEY", forHTTPHeaderField: "X-Api-Key")
    request.setValue("application/json", forHTTPHeaderField: "Content-Type")
    request.httpBody = """
        {
            "year": 1990,
            "month": 5,
            "day": 20,
            "hour": 14,
            "minute": 30,
            "second": 0,
            "latitude": 28.6139,
            "longitude": 77.209,
            "timezone": "Asia/Kolkata",
            "house_system": "placidus",
            "node_type": "true",
            "progression_year": 2026,
            "progression_month": 6,
            "progression_day": 17
        }
        """.data(using: .utf8)

    let (data, _) = try await URLSession.shared.data(for: request)
    return try JSONSerialization.jsonObject(with: data) as! [String: Any]
}

import okhttp3.*
import org.json.JSONObject

val client = OkHttpClient()
val JSON = "application/json; charset=utf-8".toMediaType()

fun getAscendant(callback: (JSONObject) -> Unit) {
    val payload = """
    {
        "year": 1990,
        "month": 5,
        "day": 20,
        "hour": 14,
        "minute": 30,
        "second": 0,
        "latitude": 28.6139,
        "longitude": 77.209,
        "timezone": "Asia/Kolkata",
        "house_system": "placidus",
        "node_type": "true",
        "progression_year": 2026,
        "progression_month": 6,
        "progression_day": 17
    }
    """.trimIndent()

    val request = Request.Builder()
        .url("https://starsapi.com/api/v3/western/forecasting/progressions")
        .addHeader("X-Api-Key", "YOUR_API_KEY")
        .post(payload.toRequestBody(JSON))
        .build()

    client.newCall(request).enqueue(object : Callback {
        override fun onResponse(call: Call, response: Response) {
            callback(JSONObject(response.body!!.string()))
        }
        override fun onFailure(call: Call, e: java.io.IOException) {
            e.printStackTrace()
        }
    })
}

package main

import (
    "bytes"
    "encoding/json"
    "fmt"
    "net/http"
    "os"
)

func main() {
    payload, _ := json.Marshal(map[string]interface{}{
        "year": 1990,
        "month": 5,
        "day": 20,
        "hour": 14,
        "minute": 30,
        "second": 0,
        "latitude": 28.6139,
        "longitude": 77.209,
        "timezone": "Asia/Kolkata",
        "house_system": "placidus",
        "node_type": "true",
        "progression_year": 2026,
        "progression_month": 6,
        "progression_day": 17,
    })

    req, _ := http.NewRequest("POST",
        "https://starsapi.com/api/v3/western/forecasting/progressions",
        bytes.NewBuffer(payload))
    req.Header.Set("X-Api-Key", os.Getenv("STARSAPI_KEY"))
    req.Header.Set("Content-Type", "application/json")

    resp, _ := http.DefaultClient.Do(req)
    defer resp.Body.Close()

    var result map[string]interface{}
    json.NewDecoder(resp.Body).Decode(&result)
    fmt.Println(result["data"])
}

require 'net/http'
require 'json'

uri = URI('https://starsapi.com/api/v3/western/forecasting/progressions')
payload = {
  'year' => 1990,
  'month' => 5,
  'day' => 20,
  'hour' => 14,
  'minute' => 30,
  'second' => 0,
  'latitude' => 28.6139,
  'longitude' => 77.209,
  'timezone' => 'Asia/Kolkata',
  'house_system' => 'placidus',
  'node_type' => 'true',
  'progression_year' => 2026,
  'progression_month' => 6,
  'progression_day' => 17
}

req = Net::HTTP::Post.new(uri)
req['X-Api-Key'] = ENV['STARSAPI_KEY']
req['Content-Type'] = 'application/json'
req.body = payload.to_json

http = Net::HTTP.new(uri.host, uri.port)
http.use_ssl = true
res = http.request(req)

data = JSON.parse(res.body)
puts data['data'] if data['success']

200 RESPONSE

{
  "status": 200,
  "success": true,
  "data": {
    "natal_planets": { "Sun": { "longitude": 59.09, "sign": "Taurus", "...": "..." } },
    "progressed_planets": { "Sun": { "longitude": 95.12, "sign": "Cancer", "...": "..." } },
    "progressed_ascendant": { "longitude": 215.3, "sign": "Scorpio", "...": "..." },
    "progressed_midheaven": { "longitude": 125.8, "sign": "Leo", "...": "..." },
    "progressed_aspects": [
      { "progressed_planet": "Moon", "natal_planet": "Venus", "aspect": "Conjunction", "orb": 0.45 }
    ],
    "progressed_date_info": { "progressed_datetime": "...", "days_of_life": 13176, "progressed_days": 36.08 },
    "target_date": "2026-06-17",
    "target_date_text": "17 June 2026",
    "progression_date_source": "provided",
    "age_years": 36,
    "progression_text": "Progressed chart for 17 June 2026 (age 36)"
  },
  "meta": {
    "house_system": "placidus",
    "relocated": false,
    "relocation": { "latitude": 28.6139, "longitude": 77.209 },
    "endpoint": "/api/v3/western/forecasting/progressions",
    "version": "3.0"
  }
}