---

name: bitcoin-infrastructure-esplora description: | Esplora: Blockstream's HTTP-based block explorer + indexer. REST API at /api/. Powers blockstream.info, mempool.space's earlier versions, and self-hosted explorers. USE WHEN: deploying a personal block explorer, integrating with Esplora REST API, building wallet / monitoring on Esplora-style endpoint. allowed-tools: Read, Grep, Glob

Esplora

Block explorer + REST API by Blockstream. Two parts:

• electrs fork (esplora-electrs) — backend indexer.
• Esplora frontend — web UI + REST API.

Repo: github.com/Blockstream/esplora.

Setup

Heavy: requires Bitcoin Core with txindex=1 + esplora-electrs indexer + frontend Node.js process.

# Start Esplora's electrs-fork as backend
electrs --daemon-rpc-addr=127.0.0.1:8332 \
  --http-addr=127.0.0.1:3000

# Frontend serves /api proxy + UI
cd esplora && npm run dev

REST API

Public endpoint for blockstream.info:

GET /api/tx/<txid>
GET /api/block/<hash>
GET /api/address/<addr>/utxo
GET /api/address/<addr>/txs
GET /api/mempool
GET /api/fee-estimates

JSON responses; well-documented at github.com/Blockstream/esplora/blob/master/API.md.

Self-hosted explorer

Run your own:

• Privacy: queries don't go to a third party.
• Full feature: address history, mempool, fees, charts.
• Heavy: ~1-2 TB disk, several GB RAM.

Public services

• blockstream.info — Esplora's flagship instance.
• mempool.space — separate codebase but Esplora-compatible API in some endpoints.
• Lightning wallets often use Esplora REST API as light-client backend (e.g., LDK Node default).

Compared

Aspect	Esplora REST	Bitcoin Core REST	Mempool.space API
Address history	yes	no	yes
Mempool details	rich	basic	rich
Fee estimates	yes	basic	best
Self-hostable	yes	yes (no UI)	yes
API style	Esplora-spec	bitcoind REST	mempool.space spec

Common bugs

• Confused with esplora-electrs (the indexer) vs Esplora frontend — both names overlap.
• Reorg handling: address-tx history can show stale entries during deep reorgs; refresh.
• Missing CORS for public deployments; configure carefully.

See also

• electrs/SKILL.md
• mempool-space/SKILL.md
• ../core/rest-api/SKILL.md