Crypto RPC for Agents

Venice gives your agent both inference (230+ models) and blockchain access (10 EVM chains plus Starknet) through a single credential. Your agent can think, sign, and send transactions without juggling separate accounts for inference and RPC providers.

One credential, two superpowers

A single API key (or wallet) for both LLM inference and JSON-RPC calls.

11 chains supported

Ethereum, Base, Arbitrum, Optimism, Polygon, Linea, Avalanche, BSC, Blast, zkSync Era, and Starknet (mainnet plus testnets).

Stake VVV for headless funding

Stake VVV on Base to earn daily DIEM, the only fully headless funding path for a minted API key. USD and crypto top-ups are also available through the dashboard.

Keyless auth via x402

Agents can authenticate with a wallet signature and pay in USDC on Base.

Why Venice for on-chain agents?

Capability	What your agent gets
Inference	230+ text, image, video, audio, and embedding models through one OpenAI-compatible endpoint
Crypto RPC	JSON-RPC 2.0 proxy to 10 EVM chains plus Starknet (mainnet and testnets)
Authentication	Standard API key or x402 wallet auth (no Venice account required)
Funding	Autonomous: VVV staking for daily DIEM. Browser: USD or crypto top-ups via the dashboard
Batching	Up to 100 JSON-RPC calls per request, multi-chain in parallel
Idempotency	Safe retries with `Idempotency-Key` header

Authentication

Pick the auth method that matches how your agent runs.

Method	Best for	How it works
API key	Server-side agents, fixed deployments	`Authorization: Bearer <key>` header. Get a key at venice.ai/settings/api.
x402 wallet	Autonomous, crypto-native, or short-lived agents	Wallet signs a SIWE message, pays per request in USDC on Base. No Venice account needed. See the x402 guide.

Both methods share the same rate limits and billing in Venice credits.

Truly autonomous agents can mint their own API key by staking VVV on Base. See Autonomous Agent API Key Creation.

Crypto RPC quickstart

Send any JSON-RPC 2.0 method to POST /crypto/rpc/{network}.

curl https://api.venice.ai/api/v1/crypto/rpc/ethereum-mainnet \
  -H "Authorization: Bearer $VENICE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "eth_chainId",
    "params": [],
    "id": 1
  }'

Response:

{ "jsonrpc": "2.0", "id": 1, "result": "0x1" }

Response headers include X-Venice-RPC-Credits (credits charged), X-Venice-RPC-Cost-USD (dollar cost), and X-Request-ID (correlation ID).

Supported networks

Family	Mainnet	Testnets
Ethereum	`ethereum-mainnet`	`ethereum-sepolia`, `ethereum-holesky`
Base	`base-mainnet`	`base-sepolia`
Arbitrum	`arbitrum-mainnet`	`arbitrum-sepolia`
Optimism	`optimism-mainnet`	`optimism-sepolia`
Polygon	`polygon-mainnet`	`polygon-amoy`
Linea	`linea-mainnet`	`linea-sepolia`
Avalanche C-Chain	`avalanche-mainnet`	`avalanche-fuji`
BNB Smart Chain	`bsc-mainnet`	`bsc-testnet`
Blast	`blast-mainnet`	`blast-sepolia`
zkSync Era	`zksync-mainnet`	`zksync-sepolia`
Starknet	`starknet-mainnet`	`starknet-sepolia`

Use GET /crypto/rpc/networks for the live, authoritative list.

Method tiers

Methods are grouped into three credit tiers. Total cost = baseCredits[chain] × methodTier.

Tier	Multiplier	Examples
Standard	1x	`eth_call`, `eth_getBalance`, `eth_blockNumber`, `eth_sendRawTransaction`, `eth_getLogs`, `eth_getTransactionReceipt`, `eth_estimateGas`
Advanced	2x	`trace_block`, `trace_call`, `trace_transaction`, `debug_traceCall`, `debug_traceTransaction`
Large	4x	`trace_replayBlockTransactions`, `trace_replayTransaction`, `txpool_content`

Full list and pricing detail in the Crypto RPC API reference.

Agent recipes

Common patterns for AI agents that need to read and write on-chain.

Read a wallet’s native balance

curl https://api.venice.ai/api/v1/crypto/rpc/base-mainnet \
  -H "Authorization: Bearer $VENICE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "eth_getBalance",
    "params": ["0xYourWalletAddress", "latest"],
    "id": 1
  }'

Read ERC-20 token balance

Call the balanceOf(address) selector with eth_call. The data field is the 4-byte selector (0x70a08231) followed by the wallet address left-padded to 32 bytes. Easiest to let a library encode it:

import { encodeFunctionData, parseAbi } from 'viem'

const data = encodeFunctionData({
  abi: parseAbi(['function balanceOf(address) view returns (uint256)']),
  args: ['0xWalletAddress'],
})

const response = await fetch('https://api.venice.ai/api/v1/crypto/rpc/base-mainnet', {
  method: 'POST',
  headers: {
    Authorization: `Bearer ${process.env.VENICE_API_KEY}`,
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    jsonrpc: '2.0',
    method: 'eth_call',
    params: [{ to: '0xacfE6019Ed1A7Dc6f7B508C02d1b04ec88cC21bf', data }, 'latest'],
    id: 1,
  }),
})

The contract address above is VVV on Base. Swap it for any ERC-20 contract.

Send a signed transaction (full lifecycle)

Venice never holds your private keys. The agent gathers tx parameters via RPC reads, signs locally with a library like viem or ethers, then relays the raw hex through Venice.

Get the next nonce

curl https://api.venice.ai/api/v1/crypto/rpc/base-mainnet \
  -H "Authorization: Bearer $VENICE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","method":"eth_getTransactionCount","params":["0xAgentWallet","pending"],"id":1}'

Use "pending" so back-to-back sends don’t collide.

Get gas price

curl https://api.venice.ai/api/v1/crypto/rpc/base-mainnet \
  -H "Authorization: Bearer $VENICE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","method":"eth_gasPrice","params":[],"id":1}'

For EIP-1559 chains, prefer eth_feeHistory to compute maxFeePerGas and maxPriorityFeePerGas.

Estimate gas

curl https://api.venice.ai/api/v1/crypto/rpc/base-mainnet \
  -H "Authorization: Bearer $VENICE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","method":"eth_estimateGas","params":[{"from":"0xAgentWallet","to":"0xRecipient","value":"0x0","data":"0x..."}],"id":1}'

Sign locally

import { privateKeyToAccount } from 'viem/accounts'
import { base } from 'viem/chains'

const account = privateKeyToAccount(process.env.AGENT_PRIVATE_KEY)

const signed = await account.signTransaction({
  chainId: base.id,
  nonce,                  // from step 1
  gas,                    // from step 3
  maxFeePerGas,           // from step 2 (fee history)
  maxPriorityFeePerGas,   // from step 2 (fee history)
  to: '0xRecipient',
  value: 0n,
  data: '0x...',
})

Submit through Venice

curl https://api.venice.ai/api/v1/crypto/rpc/base-mainnet \
  -H "Authorization: Bearer $VENICE_API_KEY" \
  -H "Idempotency-Key: agent-tx-<id>" \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","method":"eth_sendRawTransaction","params":["0xSignedHex"],"id":1}'

Always set Idempotency-Key on relays so a network blip can’t double-broadcast.

Poll for receipt

curl https://api.venice.ai/api/v1/crypto/rpc/base-mainnet \
  -H "Authorization: Bearer $VENICE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","method":"eth_getTransactionReceipt","params":["0xTxHash"],"id":1}'

Poll every few seconds until result is non-null. Check result.status ("0x1" = success).

Every eth_sendRawTransaction call is logged server-side with the tx hash, network, request ID, and calling user ID. The signed payload itself is not retained. This audit trail exists so compromised keys used for illicit relays can be traced back to the responsible account.

Batch multiple calls (multi-chain portfolio check)

Send up to 100 JSON-RPC objects in one request. Each is validated and billed independently.

curl https://api.venice.ai/api/v1/crypto/rpc/ethereum-mainnet \
  -H "Authorization: Bearer $VENICE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '[
    { "jsonrpc": "2.0", "method": "eth_blockNumber", "params": [], "id": 1 },
    { "jsonrpc": "2.0", "method": "eth_getBalance", "params": ["0xWallet", "latest"], "id": 2 },
    { "jsonrpc": "2.0", "method": "eth_gasPrice", "params": [], "id": 3 }
  ]'

For multi-chain reads (one call per chain), issue parallel requests to different {network} endpoints.

Safe retries with idempotency

Set the Idempotency-Key header to any string matching [A-Za-z0-9_-]{1,255}. Venice caches the response for 24 hours keyed on (user, key). Replays return the cached result with Idempotent-Replayed: true and charge nothing.

curl https://api.venice.ai/api/v1/crypto/rpc/base-mainnet \
  -H "Authorization: Bearer $VENICE_API_KEY" \
  -H "Idempotency-Key: agent-tx-2026-04-21-001" \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "eth_sendRawTransaction",
    "params": ["0xSignedRawTxHex"],
    "id": 1
  }'

This is critical for transaction relays where a network blip could otherwise cause your agent to broadcast the same tx twice.

Funding the agent’s API key

Once the agent has a Venice API key, it needs spendable balance on the underlying account before paid endpoints will accept the key. There are two ways to put balance there:

Path	Autonomous?	How it works
DIEM from VVV staking	Yes	Stake VVV in the Venice Staking Smart Contract on Base. The wallet’s daily DIEM allocation is proportional to its share of the staking pool. The account needs at least 0.1 DIEM accrued before any DIEM is spendable. DIEM refreshes at 00:00 UTC. To grow daily spend, stake more VVV.
USD or crypto top-up via the dashboard	No (browser)	Sign into venice.ai with the same wallet (Sign-In-With-Ethereum), then add credits in Settings, API. Both Stripe (card) and Coinbase (crypto) live behind that page and require a browser. Credits never expire.

For an agent that runs unattended, DIEM via VVV staking is the only fully headless funding path for a minted API key today. If the agent’s daily spend exceeds its DIEM allocation, the realistic options are: stake more VVV, or have an operator sign in and top up in USD or crypto.

Autonomous VVV staking and key generation

A truly autonomous agent can manage its own VVV wallet on Base, stake it, and mint its own Venice API key with no human in the loop. The full flow:

Acquire VVV and ETH for gas

Send VVV to the agent’s wallet (or have the agent swap on Aerodrome or Uniswap), plus a small amount of ETH on Base for the two staking transactions.

Stake VVV

approve the staking contract on the VVV token, then stake(amount) on 0x321b7ff75154472B18EDb199033fF4D116F340Ff. The wallet’s sVVV balance updates atomically with the stake.

Mint an API key

GET /api/v1/api_keys/generate_web3_key returns a JWT that expires 15 minutes after issuance. Sign the raw token with the staking wallet, then POST the address, signature, and token back. Venice returns an API key bound to the user account derived from that wallet.

Minting only requires a non-zero sVVV balance, so 1 staked VVV is enough to receive a key. Spending with the key is a separate question, governed by the funding table above. See Autonomous Agent API Key Creation for the complete walkthrough with code and the full error reference.

x402 wallet auth in 30 seconds

If your agent already has a Base wallet, skip the API key entirely. The venice-x402-client SDK handles SIWE signing, top-ups, and balance tracking.

npm install venice-x402-client

import { VeniceClient } from 'venice-x402-client'

const venice = new VeniceClient(process.env.WALLET_KEY)

await venice.topUp(10) // skip if the wallet already has balance

const response = await venice.chat({
  model: 'kimi-k2-6',
  messages: [{ role: 'user', content: 'What is the latest block on Base?' }]
})

The same wallet auth works against /crypto/rpc/{network} for blockchain reads and writes. Full protocol details in the x402 guide.

Pricing

Crypto RPC is billed in Venice credits. Each response includes X-Venice-RPC-Credits (credits charged) and X-Venice-RPC-Cost-USD (dollar cost) so your agent can track spend per request.

Base credits per chain

Base credits	Chains
20	Ethereum, Base, Optimism, Arbitrum, Polygon, Linea, Avalanche, BSC, Blast, Starknet
30	zkSync Era

Cost examples

Observed pricing for standard, advanced, and large method tiers:

Call	Credits	USD cost
`eth_call` on Ethereum (20 × 1x)	20	~$0.0000140
`trace_transaction` on Ethereum (20 × 2x)	40	~$0.0000280
`trace_replayTransaction` on Ethereum (20 × 4x)	80	~$0.0000560
`eth_call` on zkSync (30 × 1x)	30	~$0.0000210

Always trust the X-Venice-RPC-Cost-USD response header for the authoritative cost. Errored items in batch requests are billed at a flat 5 credits each.

Rate limits

Tier	Requests per minute
Standard	100
Staff	1,000

When exceeded, the endpoint returns 429 with standard X-RateLimit-* response headers.

Error handling

Common HTTP responses your agent should handle:

Status	Meaning	What to do
`400`	Unsupported or unmapped JSON-RPC method, or malformed batch	Verify the method against the allowlist. The error body names the offending method.
`400`	Replay of an `Idempotency-Key` with a different body	Use a fresh key for distinct requests.
`402`	No auth header at all (response body includes `authOptions` listing both supported auth paths), or out of credits with a valid auth header	If no auth: attach `Authorization: Bearer ...` or the x402 `X-Sign-In-With-X` header. If out of credits: with a Bearer key, fund the account (DIEM, USD, or dashboard top-up); with x402 auth, call `POST /api/v1/x402/top-up` directly.
`429`	Rate limit hit (100 req/min standard, 1,000 req/min staff)	Honor `X-RateLimit-Reset` and back off. Batch up to 100 calls per request to amortize the limit.
`5xx`	Upstream RPC node hiccup	Retry with the same `Idempotency-Key` to avoid double-charging.

Per-item batch errors (e.g. invalid params on one of N calls) come back inside a 200 OK response with a JSON-RPC error field on the offending item. Those items are billed at a flat 5 credits each.

Not supported

These categories of methods are intentionally rejected:

WebSocket-only (eth_subscribe, eth_unsubscribe): the proxy is HTTP-only. Poll instead.
Stateful filters (eth_newFilter, eth_getFilterChanges, etc.): filter state is pinned to a single backend and breaks on a load-balanced proxy. Use eth_getLogs instead.
Key-holding methods (eth_sign, eth_accounts, eth_mining): hosted providers don’t hold user keys. Sign client-side and submit via eth_sendRawTransaction.
Unmapped methods: anything not allowlisted returns 400. Contact support to request additions.

Resources

Crypto RPC API Reference

Full method list, pricing, and response headers

Supported Networks

Live list of supported network slugs

x402 Wallet Auth

Authenticate and pay with a Base wallet

Autonomous Agent API Key

Mint your own key by staking VVV

Postman Collection

27 ready-to-run Crypto RPC examples

Pricing

DIEM, credit pricing, and payment options

Overview

Agents & Integrations

Getting Started

Text & Chat

Image & Video

Coding Tools

SDKs & Frameworks

One credential, two superpowers

11 chains supported

Stake VVV for headless funding

Keyless auth via x402

Why Venice for on-chain agents?

Authentication

Crypto RPC quickstart

Supported networks

Method tiers

Agent recipes

Read a wallet’s native balance

Read ERC-20 token balance

Send a signed transaction (full lifecycle)

Batch multiple calls (multi-chain portfolio check)

Safe retries with idempotency

Funding the agent’s API key

Autonomous VVV staking and key generation

x402 wallet auth in 30 seconds

Pricing

Base credits per chain

Cost examples

Rate limits

Error handling

Not supported

Resources

Crypto RPC API Reference

Supported Networks

x402 Wallet Auth

Autonomous Agent API Key

Postman Collection

Pricing

Overview

Agents & Integrations

Getting Started

Text & Chat

Image & Video

Coding Tools

SDKs & Frameworks

One credential, two superpowers

11 chains supported

Stake VVV for headless funding

Keyless auth via x402

​Why Venice for on-chain agents?

​Authentication

​Crypto RPC quickstart

​Supported networks

​Method tiers

​Agent recipes

​Read a wallet’s native balance

​Read ERC-20 token balance

​Send a signed transaction (full lifecycle)

​Batch multiple calls (multi-chain portfolio check)

​Safe retries with idempotency

​Funding the agent’s API key

​Autonomous VVV staking and key generation

​x402 wallet auth in 30 seconds

​Pricing

​Base credits per chain

​Cost examples

​Rate limits

​Error handling

​Not supported

​Resources

Crypto RPC API Reference

Supported Networks

x402 Wallet Auth

Autonomous Agent API Key

Postman Collection

Pricing

Why Venice for on-chain agents?

Authentication

Crypto RPC quickstart

Supported networks

Method tiers

Agent recipes

Read a wallet’s native balance

Read ERC-20 token balance

Send a signed transaction (full lifecycle)

Batch multiple calls (multi-chain portfolio check)

Safe retries with idempotency

Funding the agent’s API key

Autonomous VVV staking and key generation

x402 wallet auth in 30 seconds

Pricing

Base credits per chain

Cost examples

Rate limits

Error handling

Not supported

Resources