{"uid":"cap_aMHPmsDdcdaPt53C78c_K","slug":"email-preflight-validation-api-3abfe74d","name":"Email Preflight Validation API","description":"Free need-to-tool routing plus pay-per-call npm docs and TypeScript API signatures, npm breaking-change diffs, JavaScript-rendered browser snapshots and deterministic coding-agent checks via AgentCash/x402.","url":"https://x402-canary.nicolas-x402-16f380a7.workers.dev/v1/email/preflight","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"email":{"type":"string"}}},"responseSchema":{"type":"json","example":{"data":{"has_mx":true,"syntax_valid":true},"meta":{"engine":"email-preflight"}}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.02","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":"$0.02/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.02","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.02","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_ZqM5aGPzahLJYm22xBYX7","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.02","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Validates an email address for syntax correctness and MX record existence before sending","exampleAgentPrompt":"Can you do a preflight check on john.doe@example.com to see if the syntax is valid and the domain actually accepts email?","exampleUseCases":[{"title":"Pre-send email deliverability check","prompt":"Before I send this campaign, can you verify that hello@acmecorp.io has valid syntax and a working MX record so I know it won't bounce?"},{"title":"User signup email validation","prompt":"A new user just entered support@startup-xyz.com on our signup form — can you quickly check if that email address is syntactically valid and has MX records before we accept it?"},{"title":"Bulk contact list screening","prompt":"I have the address sales@bigclient.com I'm about to cold-email — can you do a preflight check to confirm the domain is set up to receive mail and the address looks legitimate?"}],"resultDescription":"Returns a JSON object with a data field containing has_mx (boolean indicating whether the domain has valid MX DNS records) and syntax_valid (boolean indicating whether the email address is syntactically well-formed), plus a meta field with engine identifier 'email-preflight'.","failureModes":["Invalid or missing email field returns validation error","Non-existent or unreachable domain may cause MX lookup timeout","Malformed JSON input returns parse error","Payment not provided or insufficient USDC balance returns 402 Payment Required","DNS resolution failures may cause has_mx to return false even for valid domains"],"whenToPreferThis":"Choose this endpoint when you need a lightweight, fast preflight check combining both syntax validation and MX record lookup in a single call before sending email or accepting user input. Prefer this over full email verification services when you need only basic deliverability signals (syntax + MX) without SMTP handshake or inbox verification, and when cost-per-call economics via x402/USDC micropayments fit your use case.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T00:41:07.023Z","isFirstParty":false}