Welcome to the Mempool API
The Mempool API is a powerful RESTful API that provides comprehensive access to Bitcoin blockchain data, mempool statistics, transaction information, mining data, and more. The API is designed for developers building Bitcoin applications, explorers, analytics tools, and wallets.The Mempool API is completely free and does not require authentication for public endpoints. All data is returned in JSON format.
Base URL
The official Mempool API is available at:Network Variations
The Mempool API supports multiple Bitcoin networks:| Network | Base URL |
|---|---|
| Mainnet | https://mempool.space/api/v1/ |
| Testnet | https://mempool.space/testnet/api/v1/ |
| Testnet4 | https://mempool.space/testnet4/api/v1/ |
| Signet | https://mempool.space/signet/api/v1/ |
| Liquid | https://liquid.network/api/v1/ |
Response Format
All API responses are returned in JSON format with appropriate HTTP status codes. The API uses standard RESTful conventions:Success Responses
- 200 OK - Request succeeded, data returned
- 204 No Content - Request succeeded, no data to return
Error Responses
Errors are returned with appropriate HTTP status codes and a JSON error object:Common HTTP Status Codes
| Status Code | Meaning | Description |
|---|---|---|
| 200 | OK | Request successful |
| 204 | No Content | Request successful, no data |
| 400 | Bad Request | Invalid parameters or request format |
| 404 | Not Found | Resource not found (transaction, block, etc.) |
| 405 | Method Not Allowed | Endpoint not available with current backend |
| 413 | Payload Too Large | Request data exceeds limits |
| 422 | Unprocessable Entity | Request valid but cannot be processed |
| 500 | Internal Server Error | Server error occurred |
| 503 | Service Unavailable | Service temporarily unavailable (e.g., syncing) |
API Categories
The Mempool API is organized into several categories:Transactions
Query transaction data, status, outspends, and broadcast transactions
Addresses
Get address balances, transaction history, and UTXOs
Blocks
Access block data, headers, and transaction lists
Mining
Mining pool statistics, hashrate data, and difficulty adjustments
Fees
Real-time fee recommendations and mempool blocks
Mempool
Current mempool state and recent transactions
Lightning Network
Lightning Network nodes, channels, and statistics
Statistics
Historical statistics over various time periods
Data Formats
Transaction IDs (txid)
Transaction IDs are 64-character hexadecimal strings:Block Hashes
Block hashes are 64-character hexadecimal strings:Addresses
Bitcoin addresses support multiple formats:- Legacy (P2PKH):
1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa - P2SH:
3J98t1WpEZ73CNmYviecrnyiWrnqRhWNLy - Bech32 (native SegWit):
bc1qw508d6qejxtdg4y5r3zarvary0c5xw7kv8f3t4 - Bech32m (Taproot):
bc1p5d7rjq7g6rdk2yhzks9smlaqtedr4dekq08ge8ztwac72sfr9rusxg3297
Amounts
All Bitcoin amounts are returned in satoshis (1 BTC = 100,000,000 satoshis).Timestamps
All timestamps are Unix timestamps (seconds since January 1, 1970 UTC).Self-Hosted Instances
You can run your own Mempool instance with the same API. The Mempool project is open-source:- GitHub: mempool/mempool
- Docker: Available via Docker for easy deployment
- Configuration: Fully configurable with your own Bitcoin node
Getting Started
Support and Resources
GitHub Repository
View source code, report issues, and contribute
Follow for updates and announcements
Telegram
Join the community discussion
API Status
Check current API status and network health
Next Steps
Authentication
Learn about API access and authentication
Rate Limits
Understand rate limiting policies