← AssetFare

USDC bridge API for AI-agent wallet funding

USDC bridge API for AI agents and agent-wallet funding: 65 curated whole-route products with validated ordered provider paths and exact 1bp fee steps. The catalog contains 3 core, 50 conditional, and 12 strategic/scarce routes and is reviewed weekly. Caller approves and signs; AssetFare never signs or submits.

Quote first, without wallet access. A quote needs no account, API key, wallet address, authentication, signature, or transaction. AssetFare never receives private keys and never signs or submits.

Every quote includes direct_route_summary, a validated ordered provider/from/to path with normalized chain:asset endpoints, exact base-unit bounds, and the AssetFare fee step. Every current public route is direct_protocol_only; external_intent remains only as a compatibility enum. route_aggregator_used=false is scoped to AssetFare's engine; it does not rule out provider-internal liquidity sourcing.

Aggregate refill, not one micropayment at a time. Do not invoke AssetFare automatically for each failed x402 call. First identify the supported source asset, destination and aggregate intended amount. Use a numeric best-from only when best_from_verified=true; otherwise follow recommendation_status. A wallet that is empty on every supported source chain is not an AssetFare use case.

Representative non-mutating quote evaluation

USD 1 remains available for connectivity/schema smoke only. Use economic_guidance.best_from_usd only when best_from_verified=true. Availability-only routes return a null threshold and make no cheapest-price claim. This is not a 100% guarantee, so confirm the fresh fee-inclusive output at the caller's actual amount. Execution selection remains separate.

POST https://api.assetfare.dev/v2/quote
{"from_chain":"arbitrum","from_token":"USDC","to_chain":"base","to_token":"USDC","amount_usd":1000}

The response shows fee-inclusive expected receive, conservative minimum receive, token-path cost, known separately paid native fees, bounded source-gas estimates, the native balance to retain, remaining unpriced costs, ETA, route steps, non-atomic risk, and either a verified best-from amount or availability-only guidance. Confirm these fresh values before any separate execution selection.

Agent decision sequence

  1. Read live capabilities, provider status, and the signed manifest.
  2. Request the exact source chain/token, destination chain/token, and intended USD amount from POST /v2/quote.
  3. Require economic_guidance.best_from_verified=true before using a numeric best-from; otherwise state only the returned availability or comparison guidance.
  4. Stop while continuation_v3.selection_status is unranked_candidate. The route recommendation does not auto-select an execution mode.
  5. Only after the caller explicitly selects execution, create the exact quote-bound approval_v3 with the caller's maximum input, minimum output, and one allowed mode. Multistep routes require session mode.
  6. If a fresh quote leaves the approved intent, provider path or bounds, stop on 409 reapproval_required. The new quote is not authority to repeat a confirmed step or start a duplicate session.
  7. Send public wallet addresses only. The caller independently verifies the receipt and payload hashes, then signs and submits with its own wallet.

Machine-readable entry points

Balance checks are outside AssetFare

AssetFare has no wallet-balance endpoint. If a caller asks to check a balance, first clarify the chain and token, request only the public wallet address, and use an independent read-only RPC or explorer. Never ask for or send a seed phrase, private key, signing key, session capability, or signed transaction.

Cross-chain workflows can be non-atomic. A failure can leave assets at a verified intermediate location. Never infer the next input from an estimate; continue only from verified receipts and actual output.