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Welcome to the technical documentation for the Otto AI Agent Swarm on the USDC / Circle Gateway surface. While our main Agent Swarm overview explains what our agents do, this page provides the specific endpoint details, request parameters, and examples needed for programmatic integration via Circle’s gasless nanopayments rail. All endpoints are accessible via x402 + Circle Gateway, allowing any developer or AI agent to pay per request in USDC with zero buyer gas by pre-funding a Circle Gateway balance once. Base URL: https://usdc.ottoai.services Protocol: x402 with Circle Gateway batched-settlement scheme — every 402 advertises scheme="exact" with a GatewayWalletBatched extra and is verified + settled by Circle’s facilitator. Payment: USDC across Circle Gateway’s supported EVM chains — Base, Arbitrum, Optimism, Polygon, and additional Gateway-supported networks. Pre-fund the GatewayWallet contract once; every request is then a signed EIP-3009 authorization (offchain, sub-second). Circle batches net positions and settles them onchain in aggregate. SDK: @circle-fin/x402-batching — Circle’s official buyer client. Discovery:

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What is Circle Gateway?

Circle Gateway is Circle’s batched-settlement rail for USDC. Instead of every request paying gas onchain, buyers pre-fund a GatewayWallet contract once, then sign EIP-3009 authorizations offchain per request. Circle’s facilitator verifies signatures, aggregates net positions across many calls, and settles them in batches. Key properties:
  • Gas-free for buyers — pre-fund once, then every call is an offchain signature
  • Sub-cent pricing — a 0.001requestactuallycosts0.001 request actually costs 0.001, not “0.001plus0.001 plus 0.30 in gas”
  • Multi-chain — one Gateway balance is reachable across every supported EVM chain
  • Agent-native — designed for high-frequency machine-to-machine payments

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USDC vs x402 vs MPP

Otto AI runs multiple pay-per-request storefronts on top of the same underlying agents. The rails overlap, but they are intentionally scoped for different jobs.
Featurex402MPPUSDC (Circle Gateway)
ProtocolCoinbase x402 V2IETF Standardx402 + Circle Gateway batched scheme
PaymentUSDC on Base, Polygon, SolanaTempo USDC.e + Stripe cardsUSDC on Gateway-supported EVM chains
Buyer gasPer-request onchainPer-request onchainNone — pre-funded + batched
HeadersPAYMENT-REQUIRED / PAYMENT-SIGNATUREWWW-Authenticate: Payment / Authorization: PaymentPAYMENT-REQUIRED / PAYMENT-SIGNATURE (with GatewayWalletBatched extra)
SDK@x402/axiosmppx@circle-fin/x402-batching
Base URLhttps://x402.ottoai.serviceshttps://mpp.ottoai.serviceshttps://usdc.ottoai.services
Endpoints (v1)3727 GET/read-only6 GET/read-only
Which should I use? If you need gas-free sub-cent calls or high-frequency reads from an agent, use USDC (Circle Gateway). If you’re already on Base/Polygon/Solana with USDC and prefer the broadest standard x402 flow, use x402. If you want Stripe cards or Tempo stablecoin payments for read-only/query access, use MPP. For exact current counts and capability coverage, see Access Paths & Coverage.

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Pricing (v1 catalog — 6 endpoints)

The USDC surface launches with a curated subset of Otto’s catalog. More routes are added as additional passthroughs land.
EndpointPriceDescription
/crypto-news$0.001Real-time crypto news with sentiment, ranked by importance
/twitter-summary$0.001Quick crypto-Twitter pulse — breaking news, trending narratives
/token-details$0.001Core market metrics (price, mcap, volume, supply, links)
/tx-explainer$0.01Plain-English explanation of any EVM transaction across 11 chains
/token-intel$0.001Deeper token intelligence — narrative + on-chain & social signals
/yield-data$0.001Live lending-yield (APY) data across Aave, Morpho, Compound, Maple
All routes are GET requests. Pricing is informational; data is not financial advice.

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How to Make a Request (Gateway Flow)

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Step 1: Pre-fund the Gateway

Deposit USDC into Circle’s GatewayWallet contract once. Every supported chain reuses the same balance. 
import { GatewayClient } from '@circle-fin/x402-batching'
import { privateKeyToAccount } from 'viem/accounts'

const account = privateKeyToAccount('0x...')
const client = new GatewayClient({ account, chain: 'base' })

// One-time deposit into the Gateway
await client.deposit({ amount: 5_000_000n }) // 5 USDC (6 decimals)

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Step 2: Initial Request (Returns 402)

curl -v https://usdc.ottoai.services/crypto-news
The server responds with HTTP 402 Payment Required and a PAYMENT-REQUIRED header. The decoded accepts[] includes a scheme="exact" option for each Gateway-supported chain, each with a GatewayWalletBatched extra: 
{
  "x402Version": 2,
  "accepts": [
    {
      "scheme": "exact",
      "network": "eip155:8453",
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "payTo": "0x...",
      "maxAmountRequired": "1000",
      "maxTimeoutSeconds": 604900,
      "extra": {
        "name": "GatewayWalletBatched",
        "verifyingContract": "0x77777777Dcc4d5A8B6E418Fd04D8997ef11000eE"
      }
    }
  ]
}

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Step 3: Pay (Offchain EIP-3009 Signature) and Retry

The GatewayClient handles signing + retry automatically — no onchain transaction, no gas: 
const response = await client.pay('https://usdc.ottoai.services/crypto-news')
const body = await response.json()
console.log(body) // { status: "success", data: { report: "..." } }
Circle’s facilitator verifies the signature, debits your Gateway balance virtually, and Otto returns the response. The net position is later settled onchain in a batch with other Gateway activity.

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Step 4: Inspect Balance

const balances = await client.getBalances()
console.log(balances) // [{ chain: 'base', balance: '4998000' }, ...]

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Endpoint Details

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/crypto-news

Real-time crypto market news with sentiment analysis and top headlines ranked by importance. 
curl https://usdc.ottoai.services/crypto-news
# (use @circle-fin/x402-batching to handle the 402)
Response: 
{
  "status": "success",
  "data": { "report": "Top headlines: ..." }
}

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/twitter-summary

Quick pulse from crypto Twitter — breaking news, trending narratives, sentiment shifts. No parameters.

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/token-details

Core market metrics for a token: price, market cap, 24h volume, supply, official links.
ParameterRequiredDescription
symbolYesToken symbol (e.g., BTC, ETH, SOL)
curl "https://usdc.ottoai.services/token-details?symbol=ETH"

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/tx-explainer

Plain-English explanation of any EVM transaction across 11 supported chains.
ParameterRequiredDescription
chainYesEVM chain slug (base, arbitrum, optimism, polygon, ethereum, …)
hashYesTransaction hash (0x-prefixed)
curl "https://usdc.ottoai.services/tx-explainer?chain=base&hash=0x..."

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/token-intel

Deeper token intelligence: narrative, context, on-chain and social signals. Routes to the same upstream as /token-alpha on the x402 surface.
ParameterRequiredDescription
symbolYesToken symbol (e.g., BTC, ETH)

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/yield-data

Live lending-yield (APY) data across whitelisted lending protocols: Aave, Morpho, Compound, Maple (Syrup). No parameters. 
curl https://usdc.ottoai.services/yield-data

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Response Format

All endpoints return JSON with a consistent envelope: 
{
  "status": "success",
  "data": {
    // service-specific payload
  }
}
On error: 
{
  "status": "failed",
  "data": "Description of what went wrong"
}
When Otto returns any HTTP status ≥ 400, the x402 settlement step is skipped — you will not be charged for a failed request.

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Circle Agent Marketplace

Otto AI is applying to Circle’s Agent Service Registry — Circle’s curated marketplace where AI agents discover and pay for USDC-priced services without subscriptions or API keys. The USDC storefront at usdc.ottoai.services is the listing under review.

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