{"uid":"cap_TG1f7e-5K92tPsAc0RpP-","slug":"stableemail-send-d6a260be","name":"StableEmail Subdomain Send","description":"Send email from your custom subdomain on stableemail.dev ($0.005)","url":"https://stableemail.dev/api/subdomain/send?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","required":["from","to","subject"],"properties":{"cc":{"type":"array","items":{"type":"string","format":"email","pattern":"^(?!\\.)(?!.*\\.\\.)([A-Za-z0-9_'+\\-\\.]*)[A-Za-z0-9_+-]@([A-Za-z0-9][A-Za-z0-9\\-]*\\.)+[A-Za-z]{2,}$"},"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}}},"maxItems":5}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["email","send","inbox","forwarding","subdomain","social"],"displayCostAmount":"0.005","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"settled","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":"$0.005/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"}]},"paymentMethods":[{"uid":"pm_wxd3BajJpa8rY632unQq7","protocol":"mpp","methodType":"crypto","chain":"tempo","mode":"charge","costAmount":"0.005","costPer":"request","priority":0,"asset":"0x20c000000000000000000000b9537d11c60e8b50","unit":"request","depositMicros":null,"planRef":null}],"brandName":"StableEmail","brandSlug":"stableemail","brandBaseUrl":"https://stableemail.dev","brandDocsUrl":"https://stableemail.dev","whatItDoes":"Sends an email from a custom subdomain address on stableemail.dev at $0.005 per message","exampleAgentPrompt":"Send an email from hello@mycompany.stableemail.dev to alice@example.com with subject 'Your order has shipped' and body 'Hi Alice, your order #1234 is on its way and should arrive by Friday!'","exampleUseCases":null,"resultDescription":"A confirmation that the email was successfully sent from the specified subdomain address, typically including a message ID or delivery acknowledgment. Costs $0.005 USDC per send.","failureModes":["Invalid or unauthorized from address (not owned subdomain) — 401/403 error","Invalid recipient email format — 400 validation error","Missing required fields (from, to, subject) — 400 error","Insufficient USDC balance — 402 payment required","Attachment too large (>5MB per attachment, max 5 attachments) — 400 error","Too many recipients (>50 in to or cc) — 400 error","Subject line too long (>998 chars) — 400 error"],"whenToPreferThis":"Choose this endpoint when you need to send email from a specific custom subdomain address you own on stableemail.dev (e.g. noreply@yourbrand.stableemail.dev), rather than sending via the generic relay@stableemail.dev address. It is cheaper ($0.005 vs $0.02) and provides branded sender identity. Ideal for transactional emails, notifications, and automated outreach where a branded subdomain sender is important and no traditional email API keys or account setup is desired.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":1,"lastUsedAt":"2026-06-12T19:08:31.003Z","lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-09T18:44:01.859Z","isFirstParty":false,"canonicalSlug":"stableemail-send-d6a260be"}