{"uid":"cap_G45OuR_8uPW810e8x-4cv","slug":"stumble-inbox-durable-capture-endpoint-d86693a4","name":"Stumble Inbox – Durable Capture Endpoint","description":"Open an inbox: a capture URL that holds anything POSTed to it for up to 7 days (an A2A push, an MCP task completion, a GitHub or payment webhook, another agent) and forwards each message to your webhook in a signed envelope, or lets you poll. The durable recipient a finished session cannot be. Up to 200 messages of 64KB, optional shared-secret header. One-time $0.10.","url":"https://stumble.vimabrosta.com/v1/inbox","method":"POST","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method","bodyType","body"],"properties":{"body":{"type":"object","properties":{"days":{"type":"integer","maximum":7,"minimum":1},"notify":{"type":"object","required":["mode"],"properties":{"url":{"type":"string"},"mode":{"enum":["webhook","poll"],"type":"string"},"format":{"enum":["json","slack","discord"],"type":"string"}}},"resume_hint":{"type":"string","maxLength":500},"require_header":{"type":"object","properties":{"name":{"type":"string"},"value":{"type":"string"}}}}},"type":{"type":"string","const":"http"},"method":{"enum":["POST"],"type":"string"},"bodyType":{"enum":["json","form-data","text"],"type":"string"}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.1","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":"$0.1/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.1","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.1","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_edrZFDgHvtB5UZ0q92FAH","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.1","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Creates a temporary capture inbox that holds any inbound HTTP POST (webhooks, agent callbacks, MCP completions) for up to 7 days and forwards them to your webhook or lets you poll, with optional shared-secret header authentication.","exampleAgentPrompt":"Open a temporary inbox that captures anything POSTed to it for 3 days, forwarding each message as JSON to my webhook at https://myserver.example.com/hooks — and require the header X-Secret with value abc123 on all incoming messages.","exampleUseCases":[{"title":"Agent callback buffer during long task","prompt":"Create a capture inbox that holds inbound messages for 2 days and lets me poll for them — I need somewhere an external agent can drop its completion callback while my orchestrator waits."},{"title":"GitHub webhook staging for new server","prompt":"Open a durable inbox URL for 5 days that forwards any POSTs it receives as JSON to https://deploy.myapp.io/github-events — I'm migrating servers and need GitHub webhooks buffered in the meantime."},{"title":"MCP task completion receiver","prompt":"I need a temporary endpoint that can catch MCP task-completion notifications for up to 7 days and forward them to my webhook at https://pipeline.example.com/mcp, with the shared secret header X-Token set to mysecret99."}],"resultDescription":"Returns a unique capture URL that any HTTP client can POST to. The inbox retains up to 200 messages of up to 64KB each for the configured number of days. Each received message is forwarded to the caller's webhook wrapped in a signed envelope, or held for polling. The response includes the inbox identifier and the capture URL to hand off to senders.","failureModes":["Inbox capacity exceeded (200 messages) — additional messages are dropped","Message size exceeds 64KB — oversized payloads rejected","Webhook delivery failure — stumble retries but eventual non-delivery if target is down","Inbox expiry — messages older than the configured day limit are deleted","Invalid require_header config — incoming messages without the correct secret are rejected","Payment not settled (x402) — inbox not created if USDC payment fails"],"whenToPreferThis":"Choose this endpoint when you need a lightweight, disposable, server-less receive endpoint for async callbacks, webhooks, or agent-to-agent messages without standing up infrastructure. Ideal for agentic workflows where a session ends but a callback is expected later, for buffering GitHub or payment webhooks during server migrations, or for providing a handoff URL to another agent or service that needs to POST a result. It is not suitable for high-volume streaming or messages larger than 64KB.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-13T18:32:31.645Z","isFirstParty":false}