Event Ingestion API Reference

This document provides the complete API reference for sending events to Flexprice. It includes all endpoints, request/response formats, error codes, and examples.

Base URL

https://api.cloud.flexprice.io/v1

Authentication

All requests require authentication using an API key in the request header:

x-api-key: <your_api_key>

Security Note: Keep your API key secure and never expose it in client-side code or public repositories.

Endpoints

Single Event

Send a single event to Flexprice. Endpoint: POST /events Headers:

Content-Type: application/json
x-api-key: <your_api_key>

Request Body:

{
  "event_name": "string",
  "external_customer_id": "string",
  "properties": {
    "string": "any"
  },
  "event_id": "string",
  "timestamp": "string",
  "source": "string"
}

Response:

Status: 202 Accepted
Body:

{
  "event_id": "string",
  "message": "Event accepted for processing"
}

Bulk Events

Send multiple events in a single request for better performance. Endpoint: POST /events/bulk Headers:

Content-Type: application/json
x-api-key: <your_api_key>

Request Body:

{
  "events": [
    {
      "event_name": "string",
      "external_customer_id": "string",
      "properties": {
        "string": "any"
      },
      "event_id": "string",
      "timestamp": "string",
      "source": "string"
    }
  ]
}

Response:

Status: 202 Accepted
Body:

{
  "event_ids": ["string"],
  "message": "Events accepted for processing"
}

Request Fields

Required Fields

Field	Type	Description	Example
`event_name`	string	Must exactly match your feature’s Event Name	`"model.usage"`
`external_customer_id`	string	Your identifier for the customer	`"cust_123"`

Conditional Fields

Field	Type	When Required	Description	Example
`properties`	object	For Sum, Max, Latest, Unique Count	Contains values to aggregate	`{"credits": 2}`
`properties.<field>`	number/string	When aggregation field is set	Exact field name from feature config	`2` or `"user_123"`

Optional Fields

Field	Type	Description	Example
`event_id`	string	Your unique identifier for the event	`"evt_abc123"`
`timestamp`	string	ISO 8601 UTC timestamp	`"2025-08-22T07:05:49.441Z"`
`source`	string	Origin of the event	`"api"`, `"worker"`

Data Types

Property Values

Numbers: Use for Sum, Max aggregations
```
"properties": { "credits": 2 }
```
Strings: Use for Unique Count, Latest aggregations
```
"properties": { "user_id": "user_123" }
```

Timestamps

Format: ISO 8601 UTC
Example: "2025-08-22T07:05:49.441Z"
Default: Server time if omitted

Examples

Basic Event (Count Aggregation)

curl --request POST \
  --url https://api.cloud.flexprice.io/v1/events \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: <your_api_key>' \
  --data '{
    "event_name": "api.calls",
    "external_customer_id": "cust_123"
  }'

Event with Properties (Sum Aggregation)

curl --request POST \
  --url https://api.cloud.flexprice.io/v1/events \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: <your_api_key>' \
  --data '{
    "event_name": "model.usage",
    "external_customer_id": "cust_123",
    "properties": {
      "credits": 2
    }
  }'

Complete Event

curl --request POST \
  --url https://api.cloud.flexprice.io/v1/events \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: <your_api_key>' \
  --data '{
    "event_name": "model.usage",
    "external_customer_id": "cust_123",
    "properties": {
      "credits": 2,
      "model": "gpt-4",
      "region": "us-east-1"
    },
    "event_id": "evt_abc123",
    "timestamp": "2025-08-22T07:05:49.441Z",
    "source": "api"
  }'

Bulk Events

curl --request POST \
  --url https://api.cloud.flexprice.io/v1/events/bulk \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: <your_api_key>' \
  --data '{
    "events": [
      {
        "event_name": "model.usage",
        "external_customer_id": "cust_123",
        "properties": { "credits": 2 }
      },
      {
        "event_name": "model.usage",
        "external_customer_id": "cust_456",
        "properties": { "credits": 5 }
      }
    ]
  }'

Language Examples

JavaScript (Node.js)

const fetch = require("node-fetch");

async function sendEvent() {
  const response = await fetch("https://api.cloud.flexprice.io/v1/events", {
    method: "POST",
    headers: {
      "Content-Type": "application/json",
      "x-api-key": process.env.FLEXPRICE_API_KEY,
    },
    body: JSON.stringify({
      event_name: "model.usage",
      external_customer_id: "cust_123",
      properties: { credits: 2 },
      source: "api",
    }),
  });

  if (response.status === 202) {
    const result = await response.json();
    console.log("Event sent:", result);
  } else {
    const error = await response.text();
    console.error("Error:", error);
  }
}

Python

import os
import requests
import json

def send_event():
    url = "https://api.cloud.flexprice.io/v1/events"
    headers = {
        "Content-Type": "application/json",
        "x-api-key": os.environ["FLEXPRICE_API_KEY"]
    }

    data = {
        "event_name": "model.usage",
        "external_customer_id": "cust_123",
        "properties": {"credits": 2},
        "source": "api"
    }

    response = requests.post(url, headers=headers, json=data)

    if response.status_code == 202:
        result = response.json()
        print("Event sent:", result)
    else:
        print("Error:", response.text)

Go

package main

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

type Event struct {
    EventName           string                 `json:"event_name"`
    ExternalCustomerID  string                 `json:"external_customer_id"`
    Properties          map[string]interface{} `json:"properties,omitempty"`
    Source              string                 `json:"source,omitempty"`
}

func sendEvent() error {
    event := Event{
        EventName:          "model.usage",
        ExternalCustomerID: "cust_123",
        Properties: map[string]interface{}{
            "credits": 2,
        },
        Source: "api",
    }

    jsonData, err := json.Marshal(event)
    if err != nil {
        return err
    }

    req, err := http.NewRequest("POST", "https://api.cloud.flexprice.io/v1/events", bytes.NewBuffer(jsonData))
    if err != nil {
        return err
    }

    req.Header.Set("Content-Type", "application/json")
    req.Header.Set("x-api-key", os.Getenv("FLEXPRICE_API_KEY"))

    client := &http.Client{}
    resp, err := client.Do(req)
    if err != nil {
        return err
    }
    defer resp.Body.Close()

    if resp.StatusCode == 202 {
        fmt.Println("Event sent successfully")
    } else {
        fmt.Printf("Error: HTTP %d\n", resp.StatusCode)
    }

    return nil
}

PHP

<?php

function sendEvent() {
    $url = 'https://api.cloud.flexprice.io/v1/events';
    $apiKey = $_ENV['FLEXPRICE_API_KEY'];

    $data = [
        'event_name' => 'model.usage',
        'external_customer_id' => 'cust_123',
        'properties' => [
            'credits' => 2
        ],
        'source' => 'api'
    ];

    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_POST, true);
    curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($data));
    curl_setopt($ch, CURLOPT_HTTPHEADER, [
        'Content-Type: application/json',
        'x-api-key: ' . $apiKey
    ]);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

    $response = curl_exec($ch);
    $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
    curl_close($ch);

    if ($httpCode == 202) {
        echo "Event sent successfully\n";
    } else {
        echo "Error: HTTP $httpCode\n";
        echo "Response: $response\n";
    }
}

Error Responses

HTTP Status Codes

Status	Description
`202 Accepted`	Event accepted for processing
`400 Bad Request`	Invalid payload or missing required fields
`401 Unauthorized`	Invalid or missing API key
`429 Too Many Requests`	Rate limit exceeded

Error Response Format

{
  "error": "Error description",
  "details": "Additional error details"
}

Common Error Messages

Missing Required Field

{
  "error": "Missing required field: event_name"
}

Invalid Event Name

{
  "error": "Event name 'unknown.event' not found"
}

Invalid Customer

{
  "error": "Customer with external_customer_id 'invalid_id' not found"
}

Invalid JSON

{
  "error": "Invalid JSON format"
}

Rate Limit Exceeded

{
  "error": "Rate limit exceeded. Try again later."
}

Rate Limits

Single events: 1000 requests per minute
Bulk events: 100 requests per minute (up to 1000 events per request)
Response: 429 status code when exceeded

Rate Limit Headers

When approaching rate limits, responses include headers:

X-RateLimit-Limit: 1000
X-RateLimit-Remaining: 50
X-RateLimit-Reset: 1640995200

Best Practices

1. Error Handling

Implement proper error handling with retries:

async function sendEventWithRetry(eventData, maxRetries = 3) {
  for (let attempt = 1; attempt <= maxRetries; attempt++) {
    try {
      const response = await fetch("https://api.cloud.flexprice.io/v1/events", {
        method: "POST",
        headers: {
          "Content-Type": "application/json",
          "x-api-key": process.env.FLEXPRICE_API_KEY,
        },
        body: JSON.stringify(eventData),
      });

      if (response.status === 202) {
        return await response.json();
      }

      if (response.status === 429) {
        // Rate limited - wait and retry
        const retryAfter =
          response.headers.get("Retry-After") || attempt * 1000;
        await new Promise((resolve) => setTimeout(resolve, retryAfter));
        continue;
      }

      throw new Error(`HTTP ${response.status}: ${await response.text()}`);
    } catch (error) {
      if (attempt === maxRetries) {
        throw error;
      }
      // Wait before retry
      await new Promise((resolve) => setTimeout(resolve, 1000 * attempt));
    }
  }
}

2. Bulk Events for High Volume

Use bulk events when sending many events:

const events = [
  { event_name: "api.calls", external_customer_id: "cust_1" },
  { event_name: "api.calls", external_customer_id: "cust_2" },
  // ... more events
];

const response = await fetch("https://api.cloud.flexprice.io/v1/events/bulk", {
  method: "POST",
  headers: {
    "Content-Type": "application/json",
    "x-api-key": process.env.FLEXPRICE_API_KEY,
  },
  body: JSON.stringify({ events }),
});

3. Idempotency

Use event_id for idempotency:

{
  "event_name": "model.usage",
  "external_customer_id": "cust_123",
  "properties": { "credits": 2 },
  "event_id": "unique_event_id_123"
}

4. Timestamps

Include timestamps for historical events:

{
  "event_name": "model.usage",
  "external_customer_id": "cust_123",
  "properties": { "credits": 2 },
  "timestamp": "2025-08-22T07:05:49.441Z"
}

Validation

Event Name Validation

Must match a feature’s Event Name exactly
Case-sensitive
Cannot be changed after feature creation

Customer Validation

external_customer_id must exist in Flexprice
Customer must be active

Property Validation

Aggregation field must exist for Sum, Max, Latest, Unique Count
Data types must match aggregation function requirements

Testing

Test Endpoint

For testing purposes, you can use the same endpoints with test data:

curl --request POST \
  --url https://api.cloud.flexprice.io/v1/events \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: <your_api_key>' \
  --data '{
    "event_name": "test.feature",
    "external_customer_id": "test_customer",
    "properties": {
      "value": 1
    }
  }'

Validation Checklist

Before sending production events:

Feature exists and is active
Event Name matches exactly
Customer exists in Flexprice
Required properties are included
Data types are correct
API key has proper permissions

Support

For API-related issues:

Check error messages for specific details
Verify your request format matches the examples
Test with a simple event first
Contact support with specific error details and examples

Documentation Index

​Base URL

​Authentication

​Endpoints

​Single Event

​Bulk Events

​Request Fields

​Required Fields

​Conditional Fields

​Optional Fields

​Data Types

​Property Values

​Timestamps

​Examples

​Basic Event (Count Aggregation)

​Event with Properties (Sum Aggregation)

​Complete Event

​Bulk Events

​Language Examples

​JavaScript (Node.js)

​Python

​Go

​PHP

​Error Responses

​HTTP Status Codes

​Error Response Format

​Common Error Messages

​Missing Required Field

​Invalid Event Name

​Invalid Customer

​Invalid JSON

​Rate Limit Exceeded

​Rate Limits

​Rate Limit Headers

​Best Practices

​1. Error Handling

​2. Bulk Events for High Volume

​3. Idempotency

​4. Timestamps

​Validation

​Event Name Validation

​Customer Validation

​Property Validation

​Testing

​Test Endpoint

​Validation Checklist

​Support

Base URL

Authentication

Endpoints

Single Event

Bulk Events

Request Fields

Required Fields

Conditional Fields

Optional Fields

Data Types

Property Values

Timestamps

Examples

Basic Event (Count Aggregation)

Event with Properties (Sum Aggregation)

Complete Event

Bulk Events

Language Examples

JavaScript (Node.js)

Python

Go

PHP

Error Responses

HTTP Status Codes

Error Response Format

Common Error Messages

Missing Required Field

Invalid Event Name

Invalid Customer

Invalid JSON

Rate Limit Exceeded

Rate Limits

Rate Limit Headers

Best Practices

1. Error Handling

2. Bulk Events for High Volume

3. Idempotency

4. Timestamps

Validation

Event Name Validation

Customer Validation

Property Validation

Testing

Test Endpoint

Validation Checklist

Support