Blockchain APIs you can pay per call

What blockchain APIs do

A blockchain API lets a program read a chain without running its own node. The plainest form is JSON-RPC: the caller sends a method such as eth_getBalance or eth_getLogs and receives the node's answer. A second form wraps those methods in typed routes that return decoded JSON, such as a transaction with its status and fee or a wallet with its token balances. A third form runs a read-only call or a gas estimate so an agent can see what a transaction would do before signing it.

An agent uses these reads to check that a payment landed, to look up a balance before paying, to read a contract's state, or to follow events emitted by a protocol. Each use needs a specific guarantee. Confirming a payment needs the receipt and enough confirmations. Pricing a transaction needs a current gas reading. Reading an old balance needs a node that keeps historical state.

The answer comes from whichever node served it. Nodes can lag the chain tip by a few blocks, two providers can disagree briefly, and a reorganization can undo a recent block. Store the block number and the chain with every answer, and wait for the confirmations your use case requires before acting on a payment.

Reading a chain is not the same as writing to it. Broadcasting a signed transaction, holding keys or approving a spend are separate actions with separate risks. This comparison is about reading state. A provider may also broadcast a transaction that was already signed; the signing still stays with the wallet.

Compare node access, decoded reads and their limits

The comparison separates five outputs. Node access forwards the methods you choose, so you get flexibility and must parse raw answers. Decoded reads return blocks, transactions, receipts, logs, balances or code as structured JSON. Read-only calls and gas estimates run a transaction against current state without sending it. ENS resolution maps names and addresses. Gas readings report current fees.

A row needs a fixed quote for node access, decoded reads or read-only calls. ENS resolution and gas readings are adjacent types: they can accompany a qualifying service but cannot bring a service into the table or set its price.

Other crypto products also read the chain but answer a different question. A token risk screen returns a verdict about a contract. A payment-receipt check confirms one transfer. A transaction preflight with a risk label is a security review. DEX prices, DeFi yields and oracle prices are market data. These products stay outside this table, even when they share a host with a node.

History depth matters as much as chain coverage. A full node that keeps current state only can still return old blocks and transactions, but it refuses state queries at past blocks; an archive node answers both. Log queries can also be capped by block range. Matched endpoint descriptions from 402rpc state that the node is not an archive node.

Each price is the cheapest endpoint of that service for that kind of data: the same number wherever this page quotes it.

Compare 15 blockchain data services

Each row keeps the selected node or chain-read endpoint and its reference quote. The ordering follows observed paying wallets for the service; it does not rank node freshness or reliability.

$/CALL is the price of the endpoint named under it: the cheapest json-rpc or node api access with the methods you choose, decoded chain reads: blocks, transactions, receipts, logs, balances, code or network state and read-only contract call or gas estimate before signing endpoint of the service or, for a service without one, its cheapest blockchain endpoint. Never the cheapest tool of a gateway. Other kinds of data have their own price in the tables below. BLOCKCHAIN ENDPOINTS counts the blockchain endpoints out of all the endpoints the service lists. BUYERS 30D counts distinct wallets that paid the whole service on-chain in 30 days, not only its blockchain endpoints. "Generalist" marks a gateway that sells more than three unrelated kinds of tools: it is never called the cheapest.

How to choose a blockchain endpoint

Start from the chain and the method

List the chains and methods the agent needs before comparing providers. A relay for one chain cannot answer another, and a typed route answers only its own question. If the agent needs eth_getLogs over a wide range or a method outside a typed list, choose node access.

Check history depth

Ask whether the node keeps historical state. Balance at an old block, a contract's past storage or a call against a past block needs an archive node. A current-state node will refuse those calls, which is better than a wrong answer but still a failed task.

Decide raw or decoded

Raw JSON-RPC keeps full control and needs parsing of hex values, units and logs. Decoded routes return readable fields, with the provider's choices about which fields to include. Keep the raw identifiers, such as hashes and block numbers, even when you use decoded output.

Plan for freshness and confirmations

Record the block number of every answer. For payments, wait for the confirmations your risk tolerance needs and re-read the receipt rather than trusting a single response. For gas, read again right before sending.

Keep keys out of read paths

Read routes never need a private key. A request that asks for one is not a read. Sign transactions in the wallet, and use the API only to read state, simulate and broadcast what was already signed.

Test the operating limits

The monitored median uptime is 100% and the median selected quote is $0.001. Monitoring latency measures our checks of the service, not the time a heavy method takes. Run the methods you will actually call, including wide log ranges and batches, and measure response time and refusals.

Choose by the output your workflow needs

Start with the output the next step consumes. The candidates below use the same type classification as the comparison table, and each job quote belongs to the lowest priced endpoint of its requested types, with the path kept.

Send JSON-RPC calls to a node

Check the chain, the methods served and the history depth. A relay that refuses archive calls or caps log ranges will fail on old blocks, and a method's cost can differ from the reference quote.

Candidates today, most buyers first: MicroTap ($0.01/call, generalist, 59 buyers) · 402rpc ($0.001/call, 14 buyers) · HostDeFi RPC Relay ($0.002/call, 1 buyer) · santyvv-data ($0.02/call, 1 buyer) · QuickNode ($0.0001/call) · Skuuy Private RPC Relay ($0.001/call) · percall — Arc agent data (pay per call) ($0.003/call)

Read a block, transaction, receipt or balance as decoded JSON

Decoded reads save parsing, but each route covers a fixed set of fields and chains. Keep the block number with the answer so a later read can tell whether the chain moved.

Candidates today, most buyers first: OneSource ($0.001/call, 1231 buyers) · MicroTap ($0.01/call, generalist, 59 buyers) · Agent Exchange ($0.001/call, generalist, 28 buyers) · ISHOB ($0.001/call, generalist, 16 buyers) · Busker ($0.005/call, generalist, 13 buyers) · AgentFund US Economic, SEC & On-Chain Data ($0.01/call, generalist, 10 buyers) · EVM State Batch ($0.05/call, 3 buyers) · santyvv-data ($0.01/call, 1 buyer) · GPUOps Blockchain Data MCP ($0.001/call) · SolMachina ($0.001/call) · percall — Arc agent data (pay per call) ($0.01/call)

Simulate a read-only call or estimate gas

A simulation runs against the state at the block it reads. Re-estimate right before signing, because the state can change before the transaction lands.

Candidates today, most buyers first: OneSource ($0.004/call, 1231 buyers) · Agent Exchange ($0.005/call, generalist, 28 buyers)

Resolve an ENS name or an address

A name can point to a new address tomorrow. Resolve it at the moment of use and show the person the address that will receive funds.

Candidates today, most buyers first: OneSource ($0.005/call, 1231 buyers) · MicroTap ($0.01/call, generalist, 59 buyers) · Agent Exchange ($0.005/call, generalist, 28 buyers)

Read current gas or priority fees

Fees move block by block. Use the reading to size a transaction now, not to schedule one later, and keep the chain and unit with the number.

Candidates today, most buyers first: OneSource ($0.001/call, 1231 buyers) · MicroTap ($0.01/call, generalist, 59 buyers) · Agent Exchange ($0.002/call, generalist, 28 buyers) · ISHOB ($0.0001/call, generalist, 16 buyers) · AgentFund US Economic, SEC & On-Chain Data ($0.001/call, generalist, 10 buyers) · santyvv-data ($0.02/call, 1 buyer) · GPUOps Blockchain Data MCP ($0.001/call) · SolMachina ($0.001/call)

What the providers describe

These paragraphs attribute chains, history limits and payment options to the provider that documents them. Reference prices follow the matching endpoint type, never an amount written in a marketing description.

OneSource

OneSource documents typed reads of Ethereum rather than a raw JSON-RPC pipe. Chain reads start at $0.001: block height, receipts, transfer logs, nonces, code and a best-effort contract classification. A read-only eth_call or a gas estimate starts at $0.004, and ENS resolution starts at $0.005. The service description names Ethereum mainnet and Sepolia. Each route returns one kind of answer, which spares the caller from building raw requests but limits the caller to the methods the provider lists.

10 blockchain endpoints of 10 · $0.001/call (GET /api/chain/block-number) · Base · uptime 30d 100% · 244 ms · 1231 buyers in 30 days

402rpc

402rpc sells Ethereum mainnet JSON-RPC through POST /rpc from $0.001. The provider describes an independently operated full node serving eth_, net_ and web3_ methods with blocks, transactions, receipts and logs from the Merge onward. By its description, it is not an archive node: historical state calls are refused and not charged, and log queries are capped in block range. The provider says price scales with method cost and that raw transactions are broadcast through public relays rather than the node itself.

1 blockchain endpoint of 1 · $0.001/call (POST /rpc) · ARB/Base/POL · uptime 30d 99.7% · 909 ms · 14 buyers in 30 days

QuickNode

QuickNode lists one paid route per chain, for Base, Ethereum and Solana mainnet, from $0.0001. The endpoint description names three ways to pay for RPC access: per request, nanopayments through Circle Gateway, or a credit drawdown with SIWX authentication. The captured quote is the nanopayment rate through Circle Gateway that the description states, and the description prices a plain per-request payment higher. Read the challenge to confirm which option a request will use before comparing it with a relay paid per request.

3 blockchain endpoints of 3 · $0.0001/call (POST /base-mainnet) · AMOY/ARCT/Base/BSP/POL/SOL/SOLD/XLYT · uptime 30d 100% · 326 ms · 0 buyers in 30 days

HostDeFi RPC Relay

HostDeFi RPC Relay lists JSON-RPC routes for Base, Ethereum and Solana from $0.002. The endpoint description describes an 82-chain relay that accepts a single call object or a batch of up to ten and returns the upstream result verbatim. A batch in one paid request changes the cost per method compared with a relay that charges every call.

3 blockchain endpoints of 3 · $0.002/call (POST /api/v1/x402/rpc/base) · ARB/AVX/Base/POL/SOL · uptime 30d 99.1% · 368 ms · 1 buyer in 30 days

EVM State Batch

EVM State Batch sells batches of read-only checks from $0.05: wallet snapshots, ERC-20 balances, allowances, contract code, block heights and bounded eth_call on Ethereum, Base, Arbitrum, Optimism and Polygon. The route name sets the batch size, and only the submitted checks run. The provider describes the answers as RPC data reported by the provider, not cryptographic proofs.

3 blockchain endpoints of 3 · $0.05/call (POST /v1/state-batch) · Base · uptime 30d 99.9% · 364 ms · 3 buyers in 30 days

Cost per call and for a larger workload

The median selected route has a reference quote of $0.001 per call. At the same request shape, 100,000 calls would total $100.00. Use the generated table as a reference calculation, then count how many calls one finished task needs.

Each service at the price of its main blockchain endpoint, the one named in the table above.

Node work is not uniform. A relay can price a heavy method such as a wide log query above a simple block-number read, and a batch can carry several methods for one payment. A decoded route may replace several raw calls with one. Measure the calls of a real task, including retries after a refusal, before comparing providers on quote alone.

Set a budget per task and a stopping rule for repeated reads. Separate a refused call, a node error and a successful answer in your records, because the provider's terms may charge them differently. Read the quote for the exact request before authorizing a payment.

Inspect a request and its payment evidence

For raw node access, 402rpc documents POST /rpc. Send a standard JSON-RPC body with the method and params, and expect a refusal for historical state, since the provider describes the node as current-state only.

The catalog reference quote for this method and path is $0.001.

The listed method and description establish the advertised contract. This explanation does not reproduce an HTTP 402 challenge or certify a paid response. Obtain the challenge for the exact request body before authorizing payment, and compare resource, method, network, asset and amount together; a quote for a cheap metadata method does not price a wide log query.

How this comparison is built

The comparison starts with services that are online and payment-ready, have a known price, a description of at least 80 characters and measured 30-day uptime of at least 90%. Task selection then reads the documented endpoints. A phrase such as RPC in a service description can make a service a candidate, but a row needs a listed route for node access, decoded chain reads or read-only calls at a fixed reference quote.

Provider claims about chains, methods, history depth, upstreams and payment options were reviewed against the public service and endpoint descriptions captured on October 22, 2026. They remain provider claims. Monitoring supplies operating figures and reference prices; it does not verify that a node is in sync or that an answer matches the canonical chain. Buyer counts describe observed paying wallets for the service, with the coverage limits explained on its linked page.

The endpoint classification supplies the comparison quote, per-type prices and job candidates. Node access, decoded reads and read-only calls can qualify a row. ENS resolution and gas readings remain adjacent types and cannot qualify a service or supply its price.

Questions

How to pay

Each service answers an unpaid call with HTTP 402 and its price; your agent signs a USDC payment on the listed network and retries. No API key, no account, no subscription. See what x402 is.