Mempool API pending transactions & MEV across EVM chains
Skip running your own mempool node on every chain. We stream unconfirmed transactions — pending swaps, transfers, MEV bundles and the live gas auction — over gRPC and WebSocket with sub-100ms latency, so you can act on a trade before it ever lands in a block.
Pick your latency. Same pending-tx data underneath.
Design your query once in GraphQL, then read the exact same pending-tx fields over gRPC, Kafka or WebSocket. For the mempool, latency is everything — gRPC is the fastest lane, with no serialization overhead between broadcast and your bot.
Binary stream of pending transactions — the lowest-latency way to read the mempool, built for snipers and MEV bots.
Guaranteed delivery with offset replay — never miss a pending tx, backfill on reconnect.
Browser-ready GraphQL subscriptions — subscribe to exactly the pending tx you filter.
The same schema for confirmed history — backtest and hydrate from genesis.
Pending transactions, decoded across every EVM mempool.
A single EVM(mempool: true, network: eth) query reads the pending pool on a chain. Filter by sender, recipient, contract or method — and watch swaps, transfers, MEV bundles and the gas auction as they form, before anything confirms.
The mempool is noisy, fragmented and per-chain — we already tamed it.
Reading pending transactions yourself means a full node with a wide-open txpool on every chain, custom decoding of calldata into real methods, and constant work to keep up with re-orgs and dropped tx — and it still stops at the chain boundary. We stream the decoded mempool to you over one schema, so you get pre-confirmation signal across every chain at once.
The mempool products people ship on us.
Each one is a filter on the same pending-tx firehose — subscribe over gRPC for bots, or WebSocket for dashboards and alerts.
Frontrun protection
Watch your wallet or contract for inbound pending tx that could front-run yours, and react — delay, bump gas or reroute — before they confirm.
Read the docs →MEV / arbitrage bot
Stream pending DEX swaps and rank them by gas price to spot sandwich and arbitrage opportunities the instant they hit the mempool.
Read the docs →Liquidation sniper
Monitor the mempool for pending transfers and lending-protocol calls that move a position toward liquidation, and queue your bid first.
Read the docs →What teams say about our data
"We did a thorough search of the market for the best onchain data. Bitquery came out on top — and now powers all live prices across Nansen. We don't think of them as a vendor. They're a partner."
Bitquery does the hard work of parsing blockchain transaction data into a usable form so that we don't have to. We use their interface to diagnose issues with complex transactions and their analytics as a starting point for our own.
They proved they had the technology to deliver sophisticated data solutions. We extended our support through the Binance X fellowship — building an open-source library of visualization widgets on their blockchain data.
The complex raw data is available at different levels of detail and from different viewpoints — whether we need simple aggregated transfers or parameters for failed contract calls. The support is responsive, friendly and quick.
Partnering with Bitquery has been highly cost-effective — leveraging their established infrastructure rather than building our own let us rapidly expand our blockchain support and reach a much broader segment of on-chain users.
Bitquery's products are very intuitive and easy to use. We currently use their products to obtain DEX-related trading and liquidity information, which saves us the manpower and tedious technical details required to develop our own system. Their excellent technical team deserves special praise; they provide near-24/7 support and resolve issues quickly. I greatly appreciate their products and work ethic.
Bitquery provides the infrastructure we rely on every day. Fast, reliable, and comprehensive across the chains that matter to our business.
Start free. Scale when you ship.
Query every blockchain on every plan — no chain is paywalled. Move to commercial when you need volume, SLAs and bulk datashares.
- All blockchains, all plans
- 10 requests / minute
- 2 streams for testing
- GraphQL IDE access
- Scalable calls, no throttling
- SQL, Cloud, Kafka & more
- 24/7 engineering access
- Dedicated onboarding & SLA
- Snowflake, BigQuery, S3, Azure
- No setup or infrastructure
- Structured for AI agents & MCP
- Audit data for custodians
Mempool & pending-tx questions, answered.
How do I get mempool data with Bitquery?
Which chains have mempool support?
Can I detect MEV and sandwich attacks?
How fast is the mempool stream?
Are pending DEX swaps decoded into methods?
How is this different from the DEX Trades API?
Ship your mempool product this week.
Free API key, pending transactions streamed over gRPC and WebSocket, no node to run. Read the mempool before it confirms in your first call.