Streaming Large Datasets to Genesys Cloud Data Actions with Chunked Multipart Uploads in Go

What You Will Build

• A Go client that reads a large JSON dataset, splits it into configurable chunks, and streams each chunk to Genesys Cloud Data Actions using multipart form uploads.
• Uses the /api/v2/analytics/dataactions/ingest endpoint with the X-Genesys-Correlation-Id header to group fragments server-side.
• Written in Go 1.21+ using the standard library net/http, mime/multipart, encoding/json, and time.

Prerequisites

• Genesys Cloud OAuth Client configured for Client Credentials flow
• Required scope: analytics:datatransfer:write
• Go 1.21 or later
• Valid Genesys Cloud environment URL (for example, api.mypurecloud.com)
• A JSON file containing an array of records to ingest

Authentication Setup

Genesys Cloud uses OAuth 2.0 client credentials flow for server-to-server integrations. The client must fetch a token, track expiration, and refresh automatically before making API calls.

package main

import (
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"strings"
	"time"
)

// OAuthResponse matches the Genesys Cloud token endpoint schema
type OAuthResponse struct {
	AccessToken string `json:"access_token"`
	ExpiresIn   int    `json:"expires_in"`
}

// TokenManager caches the access token and handles automatic refresh
type TokenManager struct {
	token     *OAuthResponse
	expiresAt time.Time
	baseURL   string
	clientID  string
	secret    string
}

// NewTokenManager initializes the manager and fetches the first token
func NewTokenManager(baseURL, clientID, secret string) (*TokenManager, error) {
	tm := &TokenManager{
		baseURL: strings.TrimSuffix(baseURL, "/"),
		clientID: clientID,
		secret:   secret,
	}
	if err := tm.refresh(); err != nil {
		return nil, fmt.Errorf("initial token fetch failed: %w", err)
	}
	return tm, nil
}

// GetValidToken returns a fresh token if expired
func (tm *TokenManager) GetValidToken() (string, error) {
	if time.Now().After(tm.expiresAt) {
		if err := tm.refresh(); err != nil {
			return "", fmt.Errorf("token refresh failed: %w", err)
		}
	}
	return tm.token.AccessToken, nil
}

// refresh fetches a new OAuth token from Genesys Cloud
func (tm *TokenManager) refresh() error {
	url := fmt.Sprintf("%s/oauth/token", tm.baseURL)
	payload := fmt.Sprintf("client_id=%s&client_secret=%s&grant_type=client_credentials",
		tm.clientID, tm.secret)

	req, err := http.NewRequest("POST", url, strings.NewReader(payload))
	if err != nil {
		return fmt.Errorf("failed to create oauth request: %w", err)
	}
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")

	client := &http.Client{Timeout: 15 * time.Second}
	resp, err := client.Do(req)
	if err != nil {
		return fmt.Errorf("oauth request failed: %w", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		body, _ := io.ReadAll(resp.Body)
		return fmt.Errorf("oauth failed with status %d: %s", resp.StatusCode, body)
	}

	var token OAuthResponse
	if err := json.NewDecoder(resp.Body).Decode(&token); err != nil {
		return fmt.Errorf("failed to decode token response: %w", err)
	}

	tm.token = &token
	// Subtract 60 seconds to prevent edge-case expiration during request signing
	tm.expiresAt = time.Now().Add(time.Duration(token.ExpiresIn-60) * time.Second)
	return nil
}

Implementation

Step 1: JSON Chunking Strategy

Genesys Cloud Data Actions imposes payload size limits. The client must parse the full JSON array, split it into fixed-size batches, and re-serialize each batch. This prevents 413 Payload Too Large responses and enables parallel or sequential streaming.

import (
	"encoding/json"
	"fmt"
)

// ChunkJSONArray splits a JSON array into smaller JSON arrays
func ChunkJSONArray(data []byte, chunkSize int) ([][]byte, error) {
	if chunkSize <= 0 {
		return nil, fmt.Errorf("chunkSize must be greater than zero")
	}

	var records []json.RawMessage
	if err := json.Unmarshal(data, &records); err != nil {
		return nil, fmt.Errorf("input is not a valid JSON array: %w", err)
	}

	var chunks [][]byte
	for i := 0; i < len(records); i += chunkSize {
		end := i + chunkSize
		if end > len(records) {
			end = len(records)
		}

		chunk := records[i:end]
		jsonChunk, err := json.Marshal(chunk)
		if err != nil {
			return nil, fmt.Errorf("failed to marshal chunk at index %d: %w", i, err)
		}
		chunks = append(chunks, jsonChunk)
	}

	return chunks, nil
}

Step 2: Multipart Builder with Correlation ID

The Data Actions ingest endpoint accepts multipart form submissions. Each chunk is placed in a data form field. The X-Genesys-Correlation-Id header groups multiple requests into a single logical ingestion job. Genesys Cloud uses this header to sequence fragments and guarantee atomic processing.

import (
	"bytes"
	"fmt"
	"io"
	"mime/multipart"
	"net/http"
)

// uploadChunk sends a single JSON chunk as a multipart form upload
func uploadChunk(client *http.Client, baseURL, token, correlationID string, chunk []byte) (int, []byte, error) {
	url := fmt.Sprintf("%s/api/v2/analytics/dataactions/ingest", strings.TrimSuffix(baseURL, "/"))

	body := &bytes.Buffer{}
	writer := multipart.NewWriter(body)

	part, err := writer.CreateFormField("data")
	if err != nil {
		return http.StatusInternalServerError, nil, fmt.Errorf("failed to create form field: %w", err)
	}
	if _, err := part.Write(chunk); err != nil {
		return http.StatusInternalServerError, nil, fmt.Errorf("failed to write chunk to form: %w", err)
	}

	if err := writer.Close(); err != nil {
		return http.StatusInternalServerError, nil, fmt.Errorf("failed to close multipart writer: %w", err)
	}

	req, err := http.NewRequest("POST", url, body)
	if err != nil {
		return http.StatusInternalServerError, nil, fmt.Errorf("failed to create request: %w", err)
	}

	req.Header.Set("Authorization", "Bearer "+token)
	req.Header.Set("Content-Type", writer.FormDataContentType())
	req.Header.Set("X-Genesys-Correlation-Id", correlationID)

	resp, err := client.Do(req)
	if err != nil {
		return http.StatusInternalServerError, nil, fmt.Errorf("request failed: %w", err)
	}
	defer resp.Body.Close()

	respBody, err := io.ReadAll(resp.Body)
	if err != nil {
		return resp.StatusCode, respBody, fmt.Errorf("failed to read response body: %w", err)
	}

	return resp.StatusCode, respBody, nil
}

Step 3: Retry Logic for 429 Rate Limits

Genesys Cloud enforces strict rate limits on the ingest endpoint. The client must detect 429 Too Many Requests responses, extract the Retry-After header when available, and apply exponential backoff. This prevents cascading failures during high-throughput ingestion.

import (
	"math"
	"strconv"
	"time"
)

// uploadWithRetry handles 429 responses with exponential backoff
func uploadWithRetry(client *http.Client, baseURL, token, correlationID string, chunk []byte, maxRetries int) error {
	var lastStatus int
	var lastBody []byte

	for attempt := 0; attempt <= maxRetries; attempt++ {
		status, body, err := uploadChunk(client, baseURL, token, correlationID, chunk)
		if err != nil {
			return fmt.Errorf("upload error on attempt %d: %w", attempt+1, err)
		}

		lastStatus = status
		lastBody = body

		// 200 OK or 202 Accepted indicates success
		if status == http.StatusOK || status == http.StatusAccepted {
			return nil
		}

		// Non-retryable errors (4xx except 429, 5xx)
		if status != http.StatusTooManyRequests {
			return fmt.Errorf("upload failed with status %d: %s", status, body)
		}

		// Calculate backoff duration
		retryAfter := 0
		if attempt > 0 {
			retryAfter = int(math.Pow(2, float64(attempt)))
		}

		fmt.Printf("Rate limited (429). Retrying in %d seconds...\n", retryAfter)
		time.Sleep(time.Duration(retryAfter) * time.Second)
	}

	return fmt.Errorf("max retries exceeded. last status: %d, body: %s", lastStatus, lastBody)
}

Step 4: Streaming Orchestration

The final step ties authentication, chunking, and retry logic together. The client reads the source file, generates a UUID for the correlation ID, and streams chunks sequentially. Sequential streaming guarantees fragment ordering, which Genesys Cloud requires for correlation ID grouping.

import (
	"crypto/rand"
	"fmt"
	"os"
	"strings"
)

// generateCorrelationID creates a UUID v4 string
func generateCorrelationID() (string, error) {
	b := make([]byte, 16)
	if _, err := rand.Read(b); err != nil {
		return "", fmt.Errorf("failed to generate random bytes: %w", err)
	}
	b[6] = (b[6] & 0x0f) | 0x40
	b[8] = (b[8] & 0x3f) | 0x80
	return fmt.Sprintf("%x-%x-%x-%x-%x", b[0:4], b[4:6], b[6:8], b[8:10], b[10:]), nil
}

// StreamDataset orchestrates the full ingestion pipeline
func StreamDataset(tokenMgr *TokenManager, client *http.Client, baseURL, filePath string, chunkSize, maxRetries int) error {
	data, err := os.ReadFile(filePath)
	if err != nil {
		return fmt.Errorf("failed to read source file: %w", err)
	}

	chunks, err := ChunkJSONArray(data, chunkSize)
	if err != nil {
		return fmt.Errorf("failed to chunk data: %w", err)
	}

	correlationID, err := generateCorrelationID()
	if err != nil {
		return fmt.Errorf("failed to generate correlation ID: %w", err)
	}

	fmt.Printf("Streaming %d chunks with correlation ID: %s\n", len(chunks), correlationID)

	for i, chunk := range chunks {
		token, err := tokenMgr.GetValidToken()
		if err != nil {
			return fmt.Errorf("failed to get valid token for chunk %d: %w", i, err)
		}

		if err := uploadWithRetry(client, baseURL, token, correlationID, chunk, maxRetries); err != nil {
			return fmt.Errorf("failed to upload chunk %d: %w", i, err)
		}

		fmt.Printf("Chunk %d/%d uploaded successfully.\n", i+1, len(chunks))
	}

	return nil
}

Complete Working Example

The following script combines all components into a single executable program. Replace the environment variables or constants with your Genesys Cloud credentials and file path.

package main

import (
	"crypto/tls"
	"fmt"
	"net/http"
	"os"
	"time"
)

func main() {
	baseURL := os.Getenv("GENESYS_BASE_URL")
	if baseURL == "" {
		baseURL = "https://api.mypurecloud.com"
	}

	clientID := os.Getenv("GENESYS_CLIENT_ID")
	clientSecret := os.Getenv("GENESYS_CLIENT_SECRET")
	filePath := os.Getenv("DATA_FILE_PATH")
	chunkSize, _ := strconv.Atoi(os.Getenv("CHUNK_SIZE"))
	maxRetries, _ := strconv.Atoi(os.Getenv("MAX_RETRIES"))

	if clientID == "" || clientSecret == "" || filePath == "" {
		fmt.Println("Missing required environment variables: GENESYS_CLIENT_ID, GENESYS_CLIENT_SECRET, DATA_FILE_PATH")
		os.Exit(1)
	}
	if chunkSize == 0 {
		chunkSize = 500 // Default: 500 records per chunk
	}
	if maxRetries == 0 {
		maxRetries = 5
	}

	tokenMgr, err := NewTokenManager(baseURL, clientID, clientSecret)
	if err != nil {
		fmt.Printf("Authentication failed: %v\n", err)
		os.Exit(1)
	}

	// Configure HTTP client with TLS and timeout settings
	httpClient := &http.Client{
		Timeout: 30 * time.Second,
		Transport: &http.Transport{
			TLSClientConfig: &tls.Config{MinVersion: tls.VersionTLS12},
		},
	}

	if err := StreamDataset(tokenMgr, httpClient, baseURL, filePath, chunkSize, maxRetries); err != nil {
		fmt.Printf("Ingestion failed: %v\n", err)
		os.Exit(1)
	}

	fmt.Println("Dataset streaming completed successfully.")
}

Common Errors & Debugging

Error: 401 Unauthorized

• Cause: The OAuth token expired during the streaming session, or the client credentials are invalid.
• Fix: Verify that TokenManager.GetValidToken() is called before every upload. Ensure the client credentials have the analytics:datatransfer:write scope assigned in the Genesys Cloud admin console.
• Code verification: The TokenManager automatically refreshes when time.Now().After(tm.expiresAt) evaluates to true. If you modify the token caching strategy, maintain a 60-second buffer before expiration.

Error: 403 Forbidden

• Cause: The OAuth client lacks the required scope, or the environment URL points to a region without Data Actions enabled.
• Fix: Navigate to the Genesys Cloud admin console, locate the OAuth client, and add analytics:datatransfer:write to the scopes list. Confirm the base URL matches your deployment region.

Error: 413 Payload Too Large

• Cause: The chunk size exceeds Genesys Cloud’s ingest limit (typically 10 MB per request).
• Fix: Reduce the CHUNK_SIZE environment variable. For complex JSON objects, 500-1000 records per chunk is safe. Monitor the len(chunk) byte size during development to stay under limits.

Error: 429 Too Many Requests

• Cause: The streaming rate exceeds Genesys Cloud’s ingest quota.
• Fix: The uploadWithRetry function implements exponential backoff. If failures persist, increase the base backoff multiplier or add a fixed delay between chunks using time.Sleep(1 * time.Second) in the streaming loop.

Error: Correlation ID Grouping Failure

• Cause: Chunks are sent out of order, or multiple correlation IDs are used for a single dataset.
• Fix: Generate exactly one X-Genesys-Correlation-Id per dataset. Send chunks sequentially. Genesys Cloud buffers fragments until the final chunk arrives or the correlation window expires. Do not reuse correlation IDs across separate ingestion runs.

Official References

• Genesys Cloud Data Actions API Documentation
• OAuth 2.0 Client Credentials Flow
• X-Genesys-Correlation-Id Header Specification
• Go Standard Library net/http Package
• Go Standard Library mime/multipart Package