mempool.space REST API

Name: mempool.space REST API
Brand: mempool.space REST API
Availability: InStock

✓ Official Vendor SpecFinanceBankingnone42 EndpointsREST

For Agents

Query Bitcoin blockchain data — blocks, transactions, addresses, mempool, mining stats, Lightning Network, and fee estimates. Open public API, no authentication required.

Install Jentic One Beta

Connect the mempool.space REST API to your agent

Jentic One is a self-hosted execution layer for AI agents. It lets your agent call the mempool.space REST API, or any other public or private API you need. You set the rules, the agent never sees your credentials, and every call is logged.

Two steps, two machines. Install the instance in a safe environment, then register your agent from wherever it runs.

Step 1: Jentic One Host machine

# On the machine that will host your Jentic One instance:
curl -fsSL https://raw.githubusercontent.com/jentic/jentic-one/main/tools/install.sh | sh

Step 2: Agent machine

# On the machine where your agent runs (keep this separate from the instance):
curl -fsSL https://raw.githubusercontent.com/jentic/jentic-one/main/tools/install.sh | sh
jentic register       # connects your agent to your Jentic One instance

Jentic One is in public beta. The setup above keeps your agent separate from the instance, which is what you want before using real credentials: an agent running as the same OS user as Jentic One can read its stored keys directly. Just evaluating? A single local install is fine to start. See the secure deployment guide for the tiers.

Capabilities

What an agent can do with mempool.space REST API.

Look up the transaction history and UTXO set for a Bitcoin address via /api/address/{address}

Retrieve a block by hash including its full transaction list and miner data

Estimate next-block, half-hour, and hour fee rates from the live mempool

GET STARTED

Start building with mempool.space REST API

Explore with Jentic

View OpenAPI Document

Use Cases

Patterns agents use mempool.space REST API for, with concrete tasks.

★ Wallet Fee Estimation

Self-custody wallets call /api/v1/fees/recommended to suggest a fee rate when the user composes a Bitcoin transaction. The endpoint returns next-block, half-hour, and hour estimates derived from real mempool state, which gives wallet UX a more accurate picture than static fee tables and helps users avoid over- or under-paying.

Call /api/v1/fees/recommended, return the next-block fee rate in sats/vB, and use it as the default in the wallet's send screen.

Bitcoin Address Monitoring

Treasury and accounting tools watch deposit addresses for incoming Bitcoin payments. /api/address/{address}/txs returns confirmed and unconfirmed transactions for an address, which lets a polling worker detect new payments, count confirmations, and reconcile against an order or invoice without running a node.

Poll /api/address/{address}/txs every 30 seconds, compare against the last seen txid, and emit a 'payment received' event when a new transaction reaches one confirmation.

Lightning Network Analytics

Lightning routing nodes and analytics dashboards consume mempool.space's Lightning endpoints to map node connectivity, channel capacity, and historical liquidity. The data underpins routing-fee strategy and capacity planning for node operators who need an external view of the public graph.

Pull the top 100 Lightning nodes by capacity, then fetch each node's channel list, and produce a CSV of node pubkey, alias, and aggregate capacity.

AI Agent On-Chain Research

An AI research agent can answer Bitcoin questions — 'what's the current next-block fee, what's the mempool backlog, is this transaction confirmed' — by chaining mempool.space calls. Through Jentic, the agent loads the address, transaction, and fee endpoints as discoverable tools and composes the answer without writing custom HTTP code.

Search Jentic for 'check bitcoin transaction status', execute /api/tx/{txid}, then if not confirmed call /api/v1/fees/recommended to suggest a fee bump.

Key Endpoints

42 endpoints — the mempool.

METHOD

PATH

DESCRIPTION

GET

/api/address/{address}

Get balance and transaction summary for an address

GET

/api/address/{address}/txs

List transactions for an address

GET

/api/address/{address}/utxo

List UTXOs for an address

GET

/api/v1/validate-address/{address}

Validate Bitcoin address format

GET

/api/block/{hash}

Get block by hash

GET

/api/v1/difficulty-adjustment

Get difficulty adjustment progress

GET

/api/v1/prices

Get current Bitcoin price

GET

/api/v1/historical-price

Get historical Bitcoin price

GET

/api/address/{address}

Get balance and transaction summary for an address

GET

/api/address/{address}/txs

List transactions for an address

GET

/api/address/{address}/utxo

List UTXOs for an address

GET

/api/v1/validate-address/{address}

Validate Bitcoin address format

GET

/api/block/{hash}

Get block by hash

Why Jentic?

Three things that make agents converge on Jentic-routed access.

Credential isolation

The hosted API needs no credentials, so most agent flows run without secret handling at all. For self-hosted instances behind auth, Jentic stores credentials encrypted in the vault and injects them at request time.

Intent-based discovery

Agents search Jentic for intents like 'check bitcoin transaction status' or 'estimate bitcoin fee' and receive the matching endpoint with its input schema, ready to execute.

Time to first call

Direct integration: half a day to wire up the address, transaction, and fee endpoints with sane retries. Through Jentic: under 15 minutes — the agent loads only the operations it needs.

FAQs

Specific to using mempool.space REST API through Jentic.

What authentication does the mempool.space REST API use?

The public hosted API requires no authentication — all 42 endpoints are open. Self-hosted mempool.space instances can sit behind a reverse proxy that adds auth; through Jentic any such credential is held in the encrypted vault and injected at request time.

Can I get a fee estimate for a Bitcoin transaction with mempool.space?

Yes. /api/v1/fees/recommended returns next-block, 30-minute, and hour fee rates in sats/vB derived from live mempool state, and /api/v1/fees/mempool-blocks exposes the projected fee bands of the next several blocks.

What are the rate limits for the mempool.space REST API?

The hosted API enforces fair-use rate limits per IP that are not numerically published in the spec. Heavy users should run a self-hosted mempool.space instance — the project is fully open source — or use a paid mirror to bypass shared limits.

How do I look up a Bitcoin address through Jentic?

Run `pip install jentic`, search for `look up bitcoin address`, load /api/address/{address}, and execute with the address. Jentic returns the address summary including balance and recent transaction count.

Does the mempool.space API cover the Lightning Network?

Yes. The API exposes Lightning Network node and channel data, including node capacity, alias, and channel topology, which lets analytics tools and routing nodes consume the public graph without running their own Lightning daemon.