# LogicNodes

> Free, Blocknative-compatible multi-chain gas price API with MCP and A2A access for AI agents.

## Endpoints
- [Gas prices](https://logicnodes.io/gasprices/blockprices): GET ?chainid=<id>&confidenceLevels=99,95,90,80,70. Default chainid=1.
- [Health](https://logicnodes.io/a2a/health): status and per-chain freshness.
- [MCP (Streamable HTTP)](https://logicnodes.io/mcp): tools get_gas_prices, list_supported_chains.
- [MCP (legacy SSE)](https://logicnodes.io/sse)
- [A2A agent card](https://logicnodes.io/.well-known/agent-card.json)
- [ERC-8004 registration](https://logicnodes.io/.well-known/erc8004-registration.json)
- [OpenAPI](https://logicnodes.io/openapi.json)

## Supported chains (chainid)
- Ethereum (1)
- Base (8453)
- Arbitrum One (42161)
- OP Mainnet (10)
- Polygon PoS (137)
- BNB Chain (56)
- Avalanche C-Chain (43114)
- Linea (59144)
- Scroll (534352)
- zkSync Era (324)
- Gnosis (100)
- Blast (81457)
- Mantle (5000)
- Celo (42220)

## Notes
- No API key required. Units are gwei. Response format matches Blocknative blockprices.
- Free tier: 120 requests/minute per IP. Over the limit you get HTTP 429 with a Retry-After header. A once-a-minute poller is never affected.
- Errors are JSON: {"error": "...", "message": "..."} with 400 (bad input) or 503 (stale data).

## Multi-chain and Aptos tools (read-only, free)
Every tool takes JSON and returns {tool, ok, value|error, provenance, receipt}. Chains are CAIP-2 ids only (eip155:8453, aptos:1, aptos:2); names like "base" are refused. Ambiguous input (e.g. the symbol USDC on Aptos) returns AMBIGUOUS_INPUT with every option, never a guess. Amounts are decimal strings.
- [Tool list with JSON Schemas](https://logicnodes.io/v1/tools): GET
- Call: POST https://logicnodes.io/v1/tools/<name> with the input as the JSON body (also available over MCP at https://logicnodes.io/mcp/v2; https://logicnodes.io/mcp keeps its original two tools)
- [Aptos guide](https://logicnodes.io/aptos)
- chain_info: Chain info
- gas_estimate: Gas / fee estimate
- address_validate: Validate an address
- token_amount_convert: Convert token amounts
- tx_status: Transaction status
- aptos_address_validate: Validate an Aptos address
- aptos_name_resolve: Resolve an Aptos name (.apt)
- aptos_asset_resolve: Resolve an Aptos asset
- aptos_amount_convert: Convert an Aptos amount
- aptos_balance_get: Aptos balances at a ledger version
- aptos_fee_estimate: Aptos fee estimate
- aptos_tx_simulate: Simulate an Aptos transaction
- aptos_tx_decode: Decode an Aptos entry-function call
- aptos_tx_status: Aptos transaction status
- aptos_view: Call an Aptos view function
- decimal_calc: Exact decimal arithmetic
- slippage_bounds: Slippage bounds in base units
- swap_price_impact: Constant-product swap output and price impact
- money_calc: Currency-aware money math
- interest_calc: Simple and compound interest
- loan_calc: Level-payment loan
- unit_convert: Exact unit conversion
- address_format_check: Cross-chain address format check
- time_convert: Time zone conversion
- business_days: Business-day arithmetic
- evm_balance: EVM balances at one block
- evm_nonce: EVM account nonce
- evm_block: EVM block summary
- evm_tx_receipt: EVM transaction receipt
- evm_token_metadata: ERC-20 token metadata
- evm_allowance: ERC-20 allowance
- evm_contract_type: Classify an EVM address
- evm_logs: EVM event logs (bounded)
- evm_calldata_decode: Decode calldata with your ABI
- evm_log_decode: Decode an event log with your ABI
- payment_verify: Verify a token payment from a receipt
- random_from_block: Verifiable randomness from a finalized block
- erc8004_agent: ERC-8004 agent identity
- erc8004_reputation: ERC-8004 reputation evidence
- evm_spend_report: Wallet token spend report (CSV)

## More
- [Full reference](https://logicnodes.io/llms-full.txt)
- [Docs](https://logicnodes.io/docs)
- [Status](https://logicnodes.io/status)