{"uid":"cap_hiHeWSljL-uYADgxugCjj","slug":"oblique-markets-bnb-b402-payment-intent-preflight-ec713653","name":"Oblique Markets BNB/B402 Payment-Intent Preflight","description":"Use when an agent needs b402 preflight. Returns Validate BNB/B402 payment intent freshness, recipient, amount, deadline, fee cap, public BNB balance, and recent activity without custody or payment relay. $0.01.","url":"https://api.oblique.markets/api/v1/paid/b402-preflight","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"asset":{"type":"string","description":"native/BNB or a BEP-20 contract address"},"chain":{"enum":["bnb","bnb-smart-chain","eip155:56","56"],"type":"string"},"payer":{"type":"string"},"amount":{"type":"string"},"fee_cap":{"type":"string","description":"Maximum network fee in BNB"},"deadline":{"description":"ISO-8601 timestamp or Unix seconds"},"intent_id":{"type":"string"},"recipient":{"type":"string"}}},"responseSchema":{"type":"json","example":{"asset":"BNB","chain":"eip155:56","payer":"0x1111111111111111111111111111111111111111","amount":"0.01","decision":"ready","intent_id":"invoice-2026-08-21-001","recipient":"0x2222222222222222222222222222222222222222","signature":"hmac-sha256:7a4e1c9b3d5f7a9c1e3b5d7f9a1c3e5b7d9f1a3c5e7b9d1f3a5c7e9b1d3f5a7","timestamp":"2026-08-21T20:00:00.000Z","fee_cap_bnb":"0.0005","intent_hash":"sha256:9c2d7b3f6e1a4c8b0d2e5f7a9b1c3d5e7f9a1b3c5d7e9f1a3b5c7d9e1f3a5b7c9","amount_units":"10000000000000000","asset_balance":"0.125","evidence_hash":"sha256:4e8f1a2c6d8b0f2e4a6c8e0f2a4c6e8f0a2c4e6f8a0b2c4d6e8f0a2c4e6f8a0b2","signing_key_id":"b402-preflight-v1","evidence_source":"public_bsc_rpc","recent_activity":{"nonce":42,"latest_block":61500000,"lookback_blocks":2000,"incoming_transfer_count":5,"outgoing_transfer_count":3},"recipient_valid":true,"fee_headroom_bnb":"0.1245","fee_cap_sufficient":true}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.01","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.01/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_msFp_3AiqW8YVWvWhkSSO","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.01","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Validates a BNB payment intent for freshness and recipient correctness, queries public BNB balance and recent activity, and returns a signed preflight decision without taking custody or relaying payments.","exampleAgentPrompt":"Before I send this BNB payment, run a preflight check on intent ID 'int_abc123' — the recipient is 0xRecipient123, the payer is 0xPayer456, the amount is 0.5 BNB on BNB Smart Chain, deadline is 2025-12-31T23:59:59Z, and the fee cap is 0.001 BNB — give me a signed decision on whether this intent is fresh and the recipient is valid.","exampleUseCases":[{"title":"Pre-send BNB payment validation","prompt":"Before my agent releases a BNB payment, check if intent ID 'int_xyz789' is still fresh: recipient is 0xABCD1234, payer is 0xEFGH5678, amount is 1.2 BNB on eip155:56, deadline is 2025-11-01T12:00:00Z, and max fee is 0.002 BNB — return a signed preflight decision."},{"title":"BEP-20 token payment preflight","prompt":"Run a B402 preflight for a BEP-20 payment: asset contract is 0xTokenContract, chain is bnb-smart-chain, payer 0xPayerAddr, recipient 0xRecipAddr, amount 500, deadline 1735689600, intent ID 'int_tok001', and fee cap 0.0015 BNB — check balance, freshness, and recipient validity."},{"title":"Automated agent payment guard","prompt":"My trading agent is about to execute a BNB Smart Chain payment — preflight intent 'int_trade42' with payer 0xAgentWallet, recipient 0xExchangeVault, 2.0 BNB native asset, deadline 2025-10-15T08:00:00Z, fee cap 0.003 BNB — make sure the intent is valid and give me a signed go/no-go."}],"resultDescription":"Returns a signed preflight decision object indicating whether the payment intent is fresh and the recipient is valid, along with the queried public BNB balance of the payer and a summary of recent on-chain activity. No funds are moved or held — this is a read-and-sign operation only.","failureModes":["Intent expired: deadline has passed, decision returns stale/invalid status","Invalid recipient address: address fails checksum or format validation","Chain not supported: unrecognized chain identifier returns 400 error","Insufficient balance: payer BNB balance below specified amount (flagged in decision, not blocking)","Malformed asset: unrecognized asset string or invalid BEP-20 contract address","RPC/node unreachable: BNB chain query times out, returns 503 or error response","Missing required fields: intent_id, recipient, or payer absent returns 422 validation error"],"whenToPreferThis":"Use this endpoint when your agent needs a custody-free, signed validation of a BNB or BEP-20 payment intent before committing to an on-chain transaction on BNB Smart Chain. It is the right choice when you need to confirm intent freshness, recipient correctness, and payer balance in a single signed response without triggering any payment relay. Prefer this over generic blockchain RPC calls when you need a structured, decision-ready output compatible with the x402/B402 protocol flow.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-13T06:30:36.760Z","isFirstParty":false}