{"uid":"cap_2qo7J9qhcZd50s5ctMjxw","slug":"stableemail-send-e2635eee","name":"StableEmail Send","description":"Send an email from \"StableEmail\" <relay@stableemail.dev> ($0.02)","url":"https://stableemail.dev/api/send?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","required":["to","subject"],"properties":{"cc":{"type":"array","items":{"type":"string","format":"email","pattern":"^(?!\\.)(?!.*\\.\\.)([A-Za-z0-9_'+\\-\\.]*)[A-Za-z0-9_+-]@([A-Za-z0-9][A-Za-z0-9\\-]*\\.)+[A-Za-z]{2,}$"},"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,}$"},"maxItems":50,"minItems":1},"html":{"type":"string","maxLength":256000},"text":{"type":"string","maxLength":256000},"replyTo":{"type":"string","format":"email","pattern":"^(?!\\.)(?!.*\\.\\.)([A-Za-z0-9_'+\\-\\.]*)[A-Za-z0-9_+-]@([A-Za-z0-9][A-Za-z0-9\\-]*\\.)+[A-Za-z]{2,}$"},"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":{"type":"object","required":["from","success","messageId"],"properties":{"from":{"type":"string"},"success":{"type":"boolean"},"messageId":{"type":"string"}}},"example":{"request":{"to":["zero-qa@agentmail.to"],"text":"This is a test email to verify the Send API is functioning correctly. This message contains plain text content only.","subject":"Test Email - API Verification"},"response":{"from":"\"StableEmail\" <relay@stableemail.dev>","success":true,"messageId":"0100019f0c6b9227-d1b94261-8c84-4dea-946b-7058880a2030-000000"}},"exampleRequest":{"to":["zero-qa@agentmail.to"],"text":"This is a test email to verify the Send API is functioning correctly. This message contains plain text content only.","subject":"Test Email - API Verification"},"tags":["email","send","inbox","forwarding","subdomain","social"],"displayCostAmount":"0.020000","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"settled","requiresHandshake":false,"reviewCount":8,"rating":{"score":"1.00","successRate":"0.99","reviews":8,"stars":"5.0","state":"rated"},"availabilityStatus":"healthy","priceObserved":{"p10Cents":"2.0000","medianCents":"2.0000","p90Cents":"2.0000","minCents":"2.0000","maxCents":"2.0000","p95Cents":"2.0000","sampleCount":126,"varies":false,"failureChargeRate":null},"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.020000/call","primary":{"kind":"static","protocol":"mpp","network":"tempo","amountUsd":"0.02","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"mpp","network":"tempo","amountUsd":"0.02","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_313uM838VC3OcbqYVnwbA","protocol":"mpp","methodType":"crypto","chain":"tempo","mode":"charge","costAmount":"0.02","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 relay@stableemail.dev to one or more recipients with optional CC, reply-to, HTML/text body, and attachments","exampleAgentPrompt":"Send an email to alice@example.com with the subject 'Your order has shipped' and a plain-text body saying 'Hi Alice, your order #12345 has been dispatched and will arrive in 3-5 days. Thanks for shopping with us!' — set the reply-to address to support@mystore.com.","exampleUseCases":null,"resultDescription":"Confirmation that the email was dispatched from relay@stableemail.dev to the specified recipients; costs $0.02 USDC per call. No response body with tracking ID is expected — a 2xx status indicates successful delivery hand-off.","failureModes":["Invalid recipient email format returns a 400 validation error","Missing required fields (to, subject) returns a 400 error","Payment failure or insufficient USDC balance returns a 402","Attachment too large (over 5MB per attachment or more than 5 attachments) returns a 400","Recipient server rejects delivery — email may bounce silently after API returns success","Rate limiting or abuse detection may block sending"],"whenToPreferThis":"Use this endpoint when you need to send a one-off or programmatic email without setting up SMTP credentials, API keys, or an account — ideal for AI agents, automation scripts, or serverless workflows that need pay-per-use email delivery billed in USDC. Prefer this over full email platforms (SendGrid, Mailgun) when you want zero onboarding friction and micropayment pricing.","instructions":null,"reviewSummary":"StableEmail's Send capability earns perfect scores across all eight reviews, covering transactional emails, newsletters, incident alerts, and one-off agent-to-human messages. Delivery is consistently fast (typically 3–9 seconds end-to-end), returns a messageId on success, and honors reply-to headers; x402 payment on Base settles at $0.02 per send. No failures or edge-case issues are reported across any use case tested.","reviewSummaryHighlights":["Reliable delivery across diverse use cases: transactional, newsletter, incident alerts, and one-off sends","Fast response (3–9s round-trip) with messageId returned on every successful call","Clean, simple schema (to array, subject, text/html) with x402 payment at $0.02 per send"],"reviewSummaryConcerns":[],"reviewSummaryGeneratedAt":"2026-08-25T08:15:07.165Z","activationCount":760,"lastUsedAt":"2026-10-12T19:08:36.017Z","lastSuccessfullyRanAt":"2026-10-12T19:08:36.017Z","lastHealthCheckAt":"2026-10-12T15:42:00.108Z","isFirstParty":false,"canonicalSlug":"stableemail-send-e2635eee"}