Read the chain
before it confirms.
Mempool is the streaming explorer for engineers who can't wait for finality. Every pending transaction, every replacement, every reorg — in the order they actually happened on the wire.
Four panes.
One pipe.
Live tx stream, account holdings, validator pulse, gas chart. Pick any one — they all sit on the same WebSocket.
Three pipes,
one mempool.
Every tx, the moment it broadcasts.
Mempool exposes a WebSocket of every pending transaction across 47 connected nodes — deduplicated, ordered by gas price, and tagged with the originating peer. Median latency is 240 ms.
RBF and front-runs, flagged inline.
When a transaction is replaced by a higher-fee variant, we tag the replacement with the previous hash and the bump in basis points. Bots get caught in the same loop.
Confidence depth on every read.
Every response carries a confirmation depth and a reorg probability. Read at depth ≥ 12 and your application is reorg-safe by default — no stateful fork tracking required.
On-chain stream
vs CEX feed.
Five places where a real WebSocket on a real node beats a centralized REST poll. The data is public — we just made it cheap and live.
“We moved our front-run defense to Mempool in one afternoon. The bump-bps tagging is the only thing that lets us run our settlement bot without a 4-block buffer.”
Per-message
pricing.
You pay for messages on the wire — not for seats, not for projects, not for the dashboard. Predictable enough to put on a budget line.
Public REST · 10 req/s · 6h history.
- +1 API key
- +Confirmed tx lookups
- +Last 6h mempool snapshot
- +Discord channel
Live WebSocket, 90d archive, RBF tagging.
- +10 API keys
- +Live mempool WebSocket
- +RBF + front-run tagging
- +Confidence-depth on reads
- +Slack & PagerDuty hooks
- +8h SLA
Co-located node + raw mempool stream.
- +Unlimited keys
- +Raw bytes mempool stream
- +Dedicated peer infrastructure
- +Custom node placement
- +1h SLA · 24×7 incident
- +Trail of Bits attestation
Mechanics & custody.
Reorgs, RBF, peer attribution, key custody — all the answers an engineer actually asks before integrating.
No mempool is — even our own. We label each transaction with the peer that first surfaced it and the wall-clock arrival time. If you need single-source-of-truth, pin a peer and we will route only its observations to you.
Recent blocks of work.
WebSocket now compresses with zstd by default — payload size down 64%.
Reorg confidence model retrained on the last 6 months of orphan data.
Added 8 new geo-distributed peers — Frankfurt, Tokyo, São Paulo.
Confidence-depth field is now stable and back-filled across every response.
The mempool is open.
$ npm i @mempool/stream
No seat fees. No quarterly billing. The chain is the source of truth — Mempool just made it streamable.