Sendero — Agentic travel ops on Arc

Sendero turns messy travel requests into quotes, bookings, refunds, invoices, and on-chain settlement trails. Agent layer on Vercel Workflows + Fluid Compute (durable, encrypted, resumable). Money layer on Arc. Two revenue legs from day one. Clerk Billing gates SaaS tiers; x402 nanopayments meter every search, policy check, and tool call in micro-USDC, batched and settled on Arc L2 in one userOp that atomically fans funds to vendor + agency commission + Sendero fee + reputation tip. Card rails can't do atomic multi-leg settlement — Arc unlocks it. On-chain core: SenderoGuestEscrow (0x640e15B2B7cBa421c93dA1514f8E6Ba3e11f8515, Arc Testnet, chain 5042002, verified). Peanut-style payment links plus a travel state machine — reserve → commit → confirm → settle — with recipient-bound ECDSA signatures, optional OTP claimCodeHash, upper-bound reservations for fare drift, buyer reclaim on timeout. Sits beside ERC-8183 escrow and ERC-8004 agent identity/reputation. Self-hosted Ponder indexer keeps events in Postgres + GraphQL. Wallets: Circle Modular Wallets (passkey MSCAs for travelers and guests) + Circle Developer-Controlled Wallets (treasury), both on Arc. Circle App Kit powers swap (USDC↔EURC), CCTP bridge, send, and unified balances across testnets. Settlement uses Circle Nanopayments + Gateway to batch thousands of off-chain signatures into one on-chain tx, eliminating per-payment gas. Souvenir NFTs ship via Circle's SCP ERC-1155 template + Gas Station; Webhooks + Event Monitors feed the indexer. Beyond flights and hotels: visa-aware quotes via Sherpa with MRZ-validated PassportVault (pgcrypto AES-256, per-tenant DEK), Gemini OCR with Zod-pinned outputs, Google Maps travel-safety briefs, and an MCP + llms.txt + OpenAPI surface so other agents can book through Sendero by spec.