Blockmetric RPC docs

Your endpoint

The chain is the first path segment, your endpoint token the second. Wallets, Hardhat and Foundry only need this URL.

Endpoint tokens start with bmr_ and only work for RPC. You create, restrict and rotate them on your RPC dashboard.

Quickstart

1. Get a token. Open Account › RPC endpoints & usage and create a token. One token works on every open chain; the limits of your plan apply.
2. Store it as an environment variable, e.g. export BLOCKMETRIC_RPC_TOKEN=bmr_…, so it never lands in your code.
3. Send your first request. The answer carries the credits it cost in X-Blockmetric-Credits.

curl -s https://rpc.blockmetric.io/eth/$BLOCKMETRIC_RPC_TOKEN \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":1,"method":"eth_blockNumber","params":[]}'

Chains

Every chain uses the same token, the same credits and the same plan limits; only the eth_getLogs span differs (HyperEVM 50 blocks).

Mainnets

Testnets

Which of them is open right now: chains and their state. Not offered yet, on the waitlist: 60 more chains, such as Robinhood Chain, Solana and Bitcoin, and 40 features, such as webhooks, streams and smart wallets. We build what enough teams ask for. Request a chain or feature

Token in the URL or in a header

Both work on every chain. Use the header form where you control the HTTP client.

curl -s https://rpc.blockmetric.io/eth \
  -H "Authorization: Bearer $BLOCKMETRIC_RPC_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":1,"method":"eth_chainId","params":[]}'

• Only endpoint tokens may be in a URL. A Blockmetric API key (bm_live_…) in a URL is refused with key_in_url: revoke a key that was in a URL.
• Never in a query string. The token belongs in the path or the Authorization header.

Batch requests

Up to 100 calls per request, 256 KB per body. Each call counts on its own for limits and credits; one bad call does not fail the others.

curl -s https://rpc.blockmetric.io/eth/$BLOCKMETRIC_RPC_TOKEN \
  -H "Content-Type: application/json" \
  -d '[
    {"jsonrpc":"2.0","id":1,"method":"eth_chainId","params":[]},
    {"jsonrpc":"2.0","id":2,"method":"eth_blockNumber","params":[]},
    {"jsonrpc":"2.0","id":3,"method":"eth_getBalance","params":["0x0000000000000000000000000000000000000000","latest"]}
  ]'

Wallets and developer tools

export ETH_RPC_URL="https://rpc.blockmetric.io/eth/$BLOCKMETRIC_RPC_TOKEN"
cast chain-id
cast block-number

Good to know

• Read-only during the beta. Sending transactions is not enabled yet. Every read method is available.
• No stateful filters. Use eth_getLogs with a block range, or eth_subscribe over WebSocket.
• Consistent reads. Your requests on one chain stay on the same node for 30 seconds, so "latest" does not jump back between two nodes.
• Service level. No SLA on the plans booked online. We publish no uptime or latency figures until we have measured them. Health per chain: https://rpc.blockmetric.io/<chain>/health (once a chain is open).
• Support: E-mail support on Starter, Growth and Scale, answered within 1–2 business days; Free has the docs, Enterprise support by contract.
• Market data too. Every account also gets a free key for the Blockmetric market-data API.

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