{"uid":"cap_fWjGblX2GpKXMeIGDUMqG","slug":"stableemail-00f732ab","name":"StableEmail Subdomain Send","description":"Send from custom subdomain","url":"https://stableemail.dev/api/subdomain/send","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"cc":{"type":"array","items":{"type":"string","format":"email","pattern":"^(?!\\.)(?!.*\\.\\.)([A-Za-z0-9_'+\\-\\.]*)[A-Za-z0-9_+-]@([A-Za-z0-9][A-Za-z0-9\\-]*\\.)+[A-Za-z]{2,}$"},"maxItems":50,"minItems":1},"to":{"type":"array","items":{"type":"string","format":"email","pattern":"^(?!\\.)(?!.*\\.\\.)([A-Za-z0-9_'+\\-\\.]*)[A-Za-z0-9_+-]@([A-Za-z0-9][A-Za-z0-9\\-]*\\.)+[A-Za-z]{2,}$"},"maxItems":50,"minItems":1},"from":{"type":"string","format":"email","pattern":"^(?!\\.)(?!.*\\.\\.)([A-Za-z0-9_'+\\-\\.]*)[A-Za-z0-9_+-]@([A-Za-z0-9][A-Za-z0-9\\-]*\\.)+[A-Za-z]{2,}$"},"html":{"type":"string","maxLength":256000},"text":{"type":"string","maxLength":256000},"replyTo":{"type":"string","format":"email","pattern":"^(?!\\.)(?!.*\\.\\.)([A-Za-z0-9_'+\\-\\.]*)[A-Za-z0-9_+-]@([A-Za-z0-9][A-Za-z0-9\\-]*\\.)+[A-Za-z]{2,}$"},"subject":{"type":"string","maxLength":998,"minLength":1},"attachments":{"type":"array","items":{"type":"object","required":["content","contentType","filename"],"properties":{"content":{"type":"string","maxLength":5000000},"filename":{"type":"string","maxLength":255,"minLength":1},"contentType":{"type":"string","maxLength":255,"minLength":1}},"additionalProperties":false},"maxItems":5}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.005","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"settled","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"1.00","reviews":0,"stars":null,"state":"rated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.005/call","primary":{"kind":"static","protocol":"mpp","network":"tempo","amountUsd":"0.005","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"mpp","network":"tempo","amountUsd":"0.005","per":"call","confidence":"exact"},{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_EoSUtUD74vrAV57DVr5k5","protocol":"mpp","methodType":"crypto","chain":"tempo","mode":"charge","costAmount":"0.005","costPer":"request","priority":0,"asset":null,"unit":"request","depositMicros":null,"planRef":null},{"uid":"pm_Y9nrMMH-AfcNY4jL_Repm","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.005","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Send an email from a custom subdomain address purchased on StableEmail","exampleAgentPrompt":"Send an email from my StableEmail custom subdomain hello@acme.stableemail.dev to jane@example.com with the subject 'Your order is confirmed' and body 'Hi Jane, your order #1234 has been confirmed and will ship tomorrow.'","exampleUseCases":null,"resultDescription":"A delivery confirmation response indicating the email was successfully dispatched from the custom subdomain address, including a message ID or status acknowledgment.","failureModes":["Subdomain not owned or not purchased — returns error indicating the subdomain is invalid or unregistered","Insufficient USDC balance — payment of $0.005 USDC rejected via x402","Malformed recipient address — validation error on the to-address","Missing required fields such as subject or body — returns 400-level error","Subdomain inbox expired or not topped up — send rejected until renewed"],"whenToPreferThis":"Choose this endpoint when the agent needs to send email from a specific custom subdomain identity (e.g. hello@mycompany.stableemail.dev) rather than a generic relay address. Prefer this over the generic relay endpoint when branding or sender identity matters. Use when the user has already purchased a custom subdomain via StableEmail's Buy endpoint.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":1,"lastUsedAt":"2026-06-12T19:10:53.839Z","lastSuccessfullyRanAt":"2026-06-12T19:10:53.839Z","lastHealthCheckAt":"2026-09-14T12:48:47.750Z","isFirstParty":false}