Webhook capture bins for agents: get a URL, wait for webhooks, set replies, verify signatures.
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Create a new webhook capture bin. Returns a public capture_url — point any webhook (Stripe, GitHub, Slack, your own service…) at it and every request sent there (any method, any subpath, headers + raw body) is stored. Then read what arrived with list_captures, get_capture, or wait_for_capture. Anonymous bins keep requests ~24h. No auth needed.
This tool takes no arguments.
This tool isn't marked read-only, so it may change something on the server or in an account you connected.
Create a new webhook capture bin. Returns a public capture_url — point any webhook (Stripe, GitHub, Slack, your own service…) at it and every request sent there (any method, any subpath, headers + raw body) is stored. Then read what arrived with list_captures, get_capture, or wait_for_capture. Anonymous bins keep requests ~24h. No auth needed.
No arguments.
{
"type": "object",
"properties": {},
"additionalProperties": false
}Get one captured request in full: method, path, query, every header, and the body. Binary bodies are returned base64-encoded (up to 8KB, with a URL for the raw bytes).
| Argument | Type | Description |
|---|---|---|
| id* | integer | capture id from list_captures / wait_for_capture |
| bin* | string | bin id or slug |
{
"type": "object",
"required": [
"bin",
"id"
],
"properties": {
"id": {
"type": "integer",
"description": "capture id from list_captures / wait_for_capture"
},
"bin": {
"type": "string",
"description": "bin id or slug"
}
},
"additionalProperties": false
}List requests captured by a bin, oldest first. Compact summaries (id, method, path, time, content-type, body size, signature status). Use get_capture for full headers/body. Pass `after` (a capture id) to only see newer captures.
| Argument | Type | Description |
|---|---|---|
| bin* | string | bin id (or custom slug) from create_bin |
| after | integer | only captures with id greater than this (default 0) |
| limit | integer | max results, 1-50 (default 20) |
{
"type": "object",
"required": [
"bin"
],
"properties": {
"bin": {
"type": "string",
"description": "bin id (or custom slug) from create_bin"
},
"after": {
"type": "integer",
"description": "only captures with id greater than this (default 0)"
},
"limit": {
"type": "integer",
"description": "max results, 1-50 (default 20)"
}
},
"additionalProperties": false
}Simulate a webhook delivery into a bin — no external sender or HTTP client needed. Seeds one realistic, clearly-labeled sample capture (default: a GitHub push event) and returns it in full, so you can exercise the whole loop (create_bin → send_test_webhook → list_captures / get_capture) entirely from MCP. Pass `example` to pick a provider payload from the /examples library (e.g. "stripe-payment-intent-succeeded", "slack-event-callback", "shopify-order-created"). Sample captures are marked as simulated and never count as real webhook traffic.
| Argument | Type | Description |
|---|---|---|
| bin* | string | bin id (or custom slug) from create_bin |
| example | string | optional example payload slug from /examples (default: a GitHub push event) |
{
"type": "object",
"required": [
"bin"
],
"properties": {
"bin": {
"type": "string",
"description": "bin id (or custom slug) from create_bin"
},
"example": {
"type": "string",
"description": "optional example payload slug from /examples (default: a GitHub push event)"
}
},
"additionalProperties": false
}Configure what a bin replies to webhook senders: HTTP status, content-type, body, custom response headers, optional delay. Body and header values support {{…}} templates rendered per-request from the INCOMING delivery — {{body.challenge}}, {{query.hub.challenge}}, {{header.x-hook-secret}}, {{hmac_sha256 body.plainToken YOUR_SECRET}} — so a bin can pass provider verification handshakes with zero code: Slack URL verification (body {{body.challenge}}), Zoom CRC (JSON with the hmac_sha256 helper), Meta/WhatsApp GET echo (text/plain {{query.hub.challenge}}), Strava (JSON {"hub.challenge":"{{query.hub.challenge}}"}), Asana (response header X-Hook-Secret: {{header.x-hook-secret}}). Only the fields you pass change; everything else keeps its current value. Works on bins created via create_bin by this same client; the incoming request is still captured in full either way.
| Argument | Type | Description |
|---|---|---|
| bin* | string | bin id (or custom slug) from create_bin |
| body | string | response body, max 10000 chars; {{…}} templates allowed |
| status | integer | HTTP status to respond with, 100-599 (bins default to 200) |
| headers | object | custom response headers as name→value (max 10; values may use {{…}} templates). Pass {} to clear. Hop-by-hop/security headers (set-cookie, location, strict-transport-security…) are rejected. |
| delay_ms | integer | artificial response delay in milliseconds, 0-10000 (for testing sender timeouts/retries) |
| content_type |
Verify a webhook signature against a secret — 25 provider-exact schemes plus a generic HMAC mode, the same engine that computes ✓/✗ badges on captures. Covers HMAC-SHA256 (GitHub, Stripe, Svix/Standard Webhooks, Shopify-style base64, URL-signing Square/HubSpot/Trello…), ECDSA (SendGrid), RSA (Kick) and HMAC-MD5 (Patreon). Pass the scheme, the secret, the delivery's headers, and the BYTE-EXACT raw body (body_base64 for binary). The secret is used only for this one in-memory computation — never stored or logged. No bin needed. If verification fails, the #1 cause is a re-serialized body: point the real webhook at a capture bin (create_bin) to get the true raw bytes first.
| Argument | Type | Description |
|---|---|---|
| url | string | full delivery URL — REQUIRED for square, hubspot and trello (the URL is part of the signed string) |
| body | string | raw request body, byte-exact as the provider sent it (not re-serialized!) |
| method | string | HTTP method of the delivery (hubspot v3 signs it; default POST) |
| scheme* | string | signature scheme (usually the provider name); "hmac" = generic HMAC over the raw body |
| secret* | string | signing secret or key exactly as the provider shows it (sendgrid/kick: the PUBLIC verification key) |
| headers | object | the delivery's HTTP headers — at least the signature/timestamp headers; names are case-insensitive |
Block until the next request arrives at a bin (or a timeout passes), then return it in full. Ideal flow: create_bin → configure the webhook sender → trigger it → wait_for_capture. If `after_id` is omitted, waits for the next capture after "now". Returns timed_out:true instead of erroring when nothing arrives.
| Argument | Type | Description |
|---|---|---|
| bin* | string | bin id or slug |
| after_id | integer | return the first capture with id greater than this; default = latest id at call time |
| timeout_seconds | integer | 1-45 seconds to wait (default 20) |
{
"type": "object",
"required": [
"bin"
],
"properties": {
"bin": {
"type": "string",
"description": "bin id or slug"
},
"after_id": {
"type": "integer",
"description": "return the first capture with id greater than this; default = latest id at call time"
},
"timeout_seconds": {
"type": "integer",
"description": "1-45 seconds to wait (default 20)"
}
},
"additionalProperties": false
}| string |
| Content-Type of the response (e.g. application/json, text/plain) |
{
"type": "object",
"required": [
"bin"
],
"properties": {
"bin": {
"type": "string",
"description": "bin id (or custom slug) from create_bin"
},
"body": {
"type": "string",
"description": "response body, max 10000 chars; {{…}} templates allowed"
},
"status": {
"type": "integer",
"description": "HTTP status to respond with, 100-599 (bins default to 200)"
},
"headers": {
"type": "object",
"description": "custom response headers as name→value (max 10; values may use {{…}} templates). Pass {} to clear. Hop-by-hop/security headers (set-cookie, location, strict-transport-security…) are rejected.",
"additionalProperties": {
"type": "string"
}
},
"delay_ms": {
"type": "integer",
"description": "artificial response delay in milliseconds, 0-10000 (for testing sender timeouts/retries)"
},
"content_type": {
"type": "string",
"description": "Content-Type of the response (e.g. application/json, text/plain)"
}
},
"additionalProperties": false
}| body_base64 |
| string |
| alternative to `body` for binary payloads: base64 of the raw body bytes |
| signature_header | string | scheme "hmac" only: which header carries the signature (default x-signature) |
{
"type": "object",
"required": [
"scheme",
"secret"
],
"properties": {
"url": {
"type": "string",
"description": "full delivery URL — REQUIRED for square, hubspot and trello (the URL is part of the signed string)"
},
"body": {
"type": "string",
"description": "raw request body, byte-exact as the provider sent it (not re-serialized!)"
},
"method": {
"type": "string",
"description": "HTTP method of the delivery (hubspot v3 signs it; default POST)"
},
"scheme": {
"enum": [
"github",
"stripe",
"svix",
"calendly",
"mailchimp",
"mux",
"workos",
"paddle",
"notion",
"patreon",
"intercom",
"zendesk",
"trello",
"webflow",
"square",
"hubspot",
"twitch",
"frameio",
"buildkite",
"airtable",
"mailgun",
"adyen",
"sendgrid",
"kick",
"hmac"
],
"type": "string",
"description": "signature scheme (usually the provider name); \"hmac\" = generic HMAC over the raw body"
},
"secret": {
"type": "string",
"description": "signing secret or key exactly as the provider shows it (sendgrid/kick: the PUBLIC verification key)"
},
"headers": {
"type": "object",
"description": "the delivery's HTTP headers — at least the signature/timestamp headers; names are case-insensitive",
"additionalProperties": {
"type": "string"
}
},
"body_base64": {
"type": "string",
"description": "alternative to `body` for binary payloads: base64 of the raw body bytes"
},
"signature_header": {
"type": "string",
"description": "scheme \"hmac\" only: which header carries the signature (default x-signature)"
}
},
"additionalProperties": false
}