API Overview

Introduction to the Chunkr API for document layout analysis and chunking

The Chunkr API is a powerful document processing service that converts documents into RAG/LLM-ready data through advanced layout analysis and intelligent chunking.

Base URL

All API requests should be made to:

https://api.chunkr.ai

API Versioning

The current API version is v1. All endpoints are prefixed with /api/v1.

Example endpoint:

https://api.chunkr.ai/api/v1/task

Request Format

The API accepts requests in two formats:

• JSON (Recommended): Content-Type: application/json
• Multipart Form Data: Content-Type: multipart/form-data (deprecated)

Response Format

All successful responses return JSON with appropriate HTTP status codes:

• 200 OK - Request successful
• 400 Bad Request - Invalid request parameters
• 401 Unauthorized - Authentication failed
• 404 Not Found - Resource not found
• 429 Too Many Requests - Rate limit exceeded
• 500 Internal Server Error - Server error

Rate Limits

The API implements intelligent rate limiting to ensure fair usage and optimal performance.

Chunkr uses a token bucket algorithm for rate limiting across different service types:

Service Rate Limits

Service	Default Rate Limit	Configurable
General OCR	5 requests/second	Yes
Segmentation	5 requests/second	Yes
LLM Processing	Varies by model	Yes

Batch Sizes

To optimize throughput, the API processes requests in batches:

• General OCR: 30 pages per batch
• Segmentation: 3 pages per batch

Rate Limit Headers

Currently, rate limit information is managed server-side. If you exceed the rate limit, you’ll receive a 429 Too Many Requests response.

When you hit a rate limit, the API will return a 429 status code with the message “Usage limit exceeded”. Implement exponential backoff in your retry logic.

Timeouts

Different operations have different timeout configurations:

• General OCR: Configurable (no default timeout)
• Segmentation: Configurable (no default timeout)
• LLM Processing: 150 seconds default
• API Request: 600 seconds (10 minutes)

File Size Limits

The API accepts files up to 1 GB by default. Both total request size and in-memory limits are enforced.

• Max Total Limit: 1 GB (configurable via MAX_TOTAL_LIMIT)
• Max Memory Limit: 1 GB (configurable via MAX_MEMORY_LIMIT)

Supported File Types

The API automatically detects file types and supports various document formats. Common MIME types include:

• PDF documents
• Images (JPEG, PNG)
• Other document formats

Health Check

Check the API health and version:

curl https://api.chunkr.ai/health

Response:

OK - Version {version}

API Documentation

Interactive API documentation is available at:

• Swagger UI: https://api.chunkr.ai/swagger-ui/
• ReDoc: https://api.chunkr.ai/redoc
• OpenAPI Spec: https://api.chunkr.ai/openapi.json

Next Steps

Authentication

Learn how to authenticate your API requests

Error Handling

Understand error responses and status codes

Task Management

Create and manage document processing tasks