Live EVM gas oracle. Returns latest block baseFeePerGas + slow/standard/fast tiers derived from priority-fee percentiles (p25/p50/p75) over the trailing 4 blocks, plus a 21,000-gas transfer cost estimate in the chain native unit. Chains: base, ethereum, polygon, arbitrum, optimism. Real-time post-training data, ~5s freshness.
/api/crypto/gas-oraclePAYMENT-SIGNATURE.The gas oracle API is a pay-per-call crypto endpoint built for AI agents and autonomous software. Live EVM gas oracle.
There is no signup and no API key. An agent (or any HTTP client) hits the endpoint, receives an x402 "402 Payment Required" challenge, signs a sub-cent USDC payment on Base or Solana, and retries — the data comes back on the paid request. That makes it a drop-in gas oracle data source for an agent tool-use loop, an MCP host, or a backend that needs crypto data on demand without onboarding to yet another vendor portal.
| Name | Type | Description |
|---|---|---|
chainrequired | string | EVM chain to query: base | ethereum | polygon | arbitrum | optimism. one of: base | ethereum | polygon | arbitrum | optimism |
# 1. Probe with no auth → 402 envelope with PaymentRequirements curl -sS 'https://2s.io/api/crypto/gas-oracle?chain=base' # 2. Sign + retry with PAYMENT-SIGNATURE: curl -sS 'https://2s.io/api/crypto/gas-oracle?chain=base' \ -H 'PAYMENT-SIGNATURE: <base64-json-payload>' # Or use the canonical runner (handles probe → sign → retry): # EVM_PRIVATE_KEY=0x... node --env-file=.env.local \ # --experimental-strip-types scripts/x402-pay.ts \ # 'https://2s.io/api/crypto/gas-oracle?chain=base'
import { TwoS } from '@2sio/sdk'
const client = new TwoS({
privateKey: process.env.EVM_PRIVATE_KEY as `0x${string}`,
})
const result = await client.crypto.gasOracle({
"chain": "base"
})
console.log('endpoint:', result.endpoint)
console.log('cost:', result.costUsd, 'USDC')
console.log('tx:', result.settlement?.txHash)
console.log('data:', result.data)import os
from twosio import TwoS
client = TwoS(private_key=os.environ["EVM_PRIVATE_KEY"])
result = client.crypto.gas_oracle(chain="base")
print("endpoint:", result.endpoint)
print("cost:", result.cost_usd, "USDC")
print("tx:", (result.settlement or {}).get("tx_hash"))
print("data:", result.data)// 1. Add @2sio/mcp to your MCP host config (Claude Desktop example below).
// EVM_PRIVATE_KEY funds x402 payments per call.
// claude_desktop_config.json
{
"mcpServers": {
"2sio": {
"command": "npx",
"args": ["-y", "@2sio/mcp"],
"env": { "EVM_PRIVATE_KEY": "0x..." }
}
}
}
// 2. Once the server is running, agents call this tool via standard MCP:
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "crypto.gas-oracle",
"arguments": {
"chain": "base"
}
}
}# pip install langchain-twosio langchain-anthropic
import os
from langchain_twosio import get_twosio_tools
from langchain_anthropic import ChatAnthropic
from langgraph.prebuilt import create_react_agent
tools = get_twosio_tools(private_key=os.environ["EVM_PRIVATE_KEY"])
llm = ChatAnthropic(model="claude-haiku-4-5", temperature=0)
agent = create_react_agent(llm, tools)
# The agent will pick "twosio_crypto_gas_oracle" when the prompt matches.
result = agent.invoke({
"messages": [("user", "...prompt that requires crypto.gas-oracle...")]
})
print(result["messages"][-1].content)# pip install llama-index-tools-twosio llama-index-llms-anthropic
import asyncio, os
from llama_index_tools_twosio import get_twosio_tools
from llama_index.llms.anthropic import Anthropic
from llama_index.core.agent.workflow import FunctionAgent
tools = get_twosio_tools(private_key=os.environ["EVM_PRIVATE_KEY"])
llm = Anthropic(model="claude-haiku-4-5")
agent = FunctionAgent(tools=tools, llm=llm)
# The agent will pick "twosio_crypto_gas_oracle" when the prompt matches.
response = asyncio.run(agent.run("...prompt that requires crypto.gas-oracle..."))
print(response)| Field | Type | Description |
|---|---|---|
ok | boolean | one of: true |
items | array | |
total | integer | Total matching rows upstream; null when unknown. |
source | object |
{
"ok": true,
"items": [
{}
],
"total": 1,
"source": {
"provider": "example",
"url": "example",
"license": "example"
}
}