gov.senate-votes

US Senate roll-call votes, newest first by vote date. Each record includes congress + session + vote_number, vote question + result + title + majority requirement, vote date/time, document name (e.g., S. 5, H.R. 4499), document title, grand totals (yeas/nays/present/absent), AND per-party breakdown (D/R/I yea/nay/present/absent counts derived from member-level vote_cast). Filters (all optional, AND-combined): congress, session (1 or 2), result substring, document substring (e.g., 'S. 5'), since/until (vote_date), limit + offset. Locally aggregated from senate.gov XML feeds (refreshed daily). Public-domain US government records.

price
$0.0024 USDC per call
method
GET/api/gov/senate-votes
payment
x402 v2 · USDC on Base (EIP-3009) or Solana (SPL transfer)
auth
None. Sign the payment, retry with PAYMENT-SIGNATURE.

Overview

The senate votes API is a pay-per-call gov endpoint built for AI agents and autonomous software. US Senate roll-call votes, newest first by vote date.

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 senate votes data source for an agent tool-use loop, an MCP host, or a backend that needs gov data on demand without onboarding to yet another vendor portal.

Use cases

Parameters

NameTypeDescription
congressintegerFilter by Congress number. The 119th Congress = 2025-2026.
min 100 · max 200
sessionintegerFilter by session (1 = odd year, 2 = even year of a Congress).
resultstringFilter by vote result (case-insensitive substring). Examples: "Agreed", "Rejected", "Cloture".
min 2 chars · max 60 chars
documentstringFilter by document name substring (case-insensitive on document_name). Examples: "S. 5", "H.R. 4499", "H.R.".
min 2 chars · max 40 chars
sincestringEarliest vote date (YYYY-MM-DD).
match ^\d{4}-\d{2}-\d{2}$
untilstringLatest vote date (YYYY-MM-DD).
match ^\d{4}-\d{2}-\d{2}$
limitintegerMax records (1-100). Default 25.
min 1 · max 100
offsetintegerOffset for pagination. Default 0.
min 0 · max 100000

Code samples

cURLbash
# 1. Probe with no auth → 402 envelope with PaymentRequirements
curl -sS 'https://2s.io/api/gov/senate-votes?congress=100&session=1&result=xx&document=xx&since=2024-01-01&until=2024-01-01&limit=25&offset=0'

# 2. Sign + retry with PAYMENT-SIGNATURE:
curl -sS 'https://2s.io/api/gov/senate-votes?congress=100&session=1&result=xx&document=xx&since=2024-01-01&until=2024-01-01&limit=25&offset=0' \
  -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/gov/senate-votes?congress=100&session=1&result=xx&document=xx&since=2024-01-01&until=2024-01-01&limit=25&offset=0'
TypeScript / Node — @2sio/sdktypescript
import { TwoS } from '@2sio/sdk'

const client = new TwoS({
  privateKey: process.env.EVM_PRIVATE_KEY as `0x${string}`,
})

const result = await client.gov.senateVotes({
  "congress": 100,
  "session": 1,
  "result": "xx",
  "document": "xx",
  "since": "2024-01-01",
  "until": "2024-01-01",
  "limit": 25,
  "offset": 0
})

console.log('endpoint:', result.endpoint)
console.log('cost:', result.costUsd, 'USDC')
console.log('tx:', result.settlement?.txHash)
console.log('data:', result.data)
Python — 2siopython
import os
from twosio import TwoS

client = TwoS(private_key=os.environ["EVM_PRIVATE_KEY"])

result = client.gov.senate_votes(congress=100, session=1, result="xx", document="xx", since="2024-01-01", until="2024-01-01", limit=25, offset=0)

print("endpoint:", result.endpoint)
print("cost:", result.cost_usd, "USDC")
print("tx:", (result.settlement or {}).get("tx_hash"))
print("data:", result.data)
MCP — Claude Desktop / AgentKit / any MCP hostjson
// 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": "gov.senate-votes",
    "arguments": {
      "congress": 100,
      "session": 1,
      "result": "xx",
      "document": "xx",
      "since": "2024-01-01",
      "until": "2024-01-01",
      "limit": 25,
      "offset": 0
    }
  }
}

Response

FieldTypeDescription
okboolean
one of: true
itemsarray
totalintegerTotal matching rows upstream; null when unknown.
sourceobject
metaobject
Example response datajson
{
  "ok": true,
  "items": [
    {
      "congress": 1,
      "session": 1,
      "voteNumber": 1,
      "congressYear": 1,
      "voteDate": "example",
      "voteTime": "example",
      "voteQuestion": "example",
      "voteResult": "example",
      "voteResultText": "example",
      "voteTitle": "example",
      "majorityRequirement": "example",
      "documentName": "example",
      "documentTitle": "example",
      "totals": {
        "yeas": 1,
        "nays": 1,
        "present": 1,
        "absent": 1
      },
      "totalsByParty": {},
      "sourceXmlUrl": "https://example.com"
    }
  ],
  "total": 1,
  "source": {
    "provider": "example",
    "url": "example",
    "license": "example"
  },
  "meta": {
    "query": {
      "congress": 1,
      "session": 1,
      "result": "example",
      "document": "example",
      "since": "example",
      "until": "example",
      "limit": 1,
      "offset": 1
    },
    "nextOffset": 1,
    "previousOffset": 1
  }
}

FAQ

Do I need an API key to use the senate votes API?
No. gov.senate-votes is x402-native — there is no signup and no API key. Your client makes the call, receives a 402 with payment requirements, signs a USDC payment, and retries. Funds come from a wallet you control.
How much does the senate votes API cost?
$0.0024 USDC per call, charged per request. There are no monthly fees, seats, or minimums — you pay only for the calls you make.
Can I try the senate votes API for free first?
Yes. Add ?trial=1 (or the header X-2s-Trial: 1) to get a free real call per endpoint per hour, so you can verify the response shape before wiring payment.
Which networks and tokens are supported?
USDC on Base (via EIP-3009 transferWithAuthorization) or Solana (SPL transfer), using the open x402 payment protocol.
How do I call gov.senate-votes from an AI agent or MCP host?
Use @2sio/sdk (TypeScript), 2sio (Python), or the @2sio/mcp server for any MCP host — each handles the probe → sign → retry loop for you. See the code samples on this page.

Discovery

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