TypeScript SDK for webhooks.cc. Create webhook endpoints, capture and search requests, wait for emails and read their codes and links, forward requests and emails to your server or Slack, send signed test webhooks, verify provider signatures, and build webhook tests with less boilerplate.

Install

pnpm add @webhooks-cc/sdk

The package also ships a testing entrypoint, and an email entrypoint with no network code:

import { captureDuring, captureEmailDuring, assertRequest } from "@webhooks-cc/sdk/testing";
import { extractCode, type EmailReceivedEvent } from "@webhooks-cc/sdk/email";

API key setup

The SDK needs an API key in whcc_... format. You can pass the key directly, but most projects load it from WHK_API_KEY so the same code works locally and in CI.

For local development, set the env var in your shell or .env.local:

export WHK_API_KEY=whcc_...

For GitHub Actions, store the key as a repository secret and expose it in the workflow:

# .github/workflows/test.yml
env:
  WHK_API_KEY: ${{ secrets.WHK_API_KEY }}

Without an API key (AI agents)

An agent can capture webhooks before anyone signs up. WebhooksCC.sandbox() registers through auth.md, solves a short proof of work (about 3 seconds) and returns a sandbox: up to 3 endpoints, 25 captured requests each and 100 in all, for 24 hours.

import { WebhooksCC } from "@webhooks-cc/sdk";

const sandbox = await WebhooksCC.sandbox({ clientName: "my-agent" });
const endpoint = await sandbox.endpoints.create();
const request = await sandbox.requests.waitFor(endpoint.slug, { timeout: "60s" });

// Connect it to a human's account: they open the link, sign in and enter the code.
const { verificationUri, userCode } = await sandbox.claim({ email: "dev@example.com" });
console.log(`Open ${verificationUri}, sign in, and enter ${userCode}`);
const client = await sandbox.waitForClaim(); // a WebhooksCC for that account

WebhooksCC.agent.* exposes the auth.md steps one by one. See AI Agents.

Quick start

import { WebhooksCC, matchAll, matchHeader, matchMethod } from "@webhooks-cc/sdk";

const client = new WebhooksCC({ apiKey: process.env.WHK_API_KEY! });

const endpoint = await client.endpoints.create({
  name: "stripe-test",
  expiresIn: "1h",
});

await yourApp.registerWebhook(endpoint.url!);
await yourApp.triggerCheckout();

const request = await client.requests.waitFor(endpoint.slug, {
  timeout: "30s",
  match: matchAll(matchMethod("POST"), matchHeader("stripe-signature")),
});

console.log(request.body);

await client.endpoints.delete(endpoint.slug);

Client options

const client = new WebhooksCC({
  apiKey: "whcc_...",
  retry: {
    maxAttempts: 3,
    backoffMs: 500,
  },
  hooks: {
    onRequest: ({ method, url }) => console.log(method, url),
    onResponse: ({ status, durationMs }) => console.log(status, durationMs),
    onError: ({ error }) => console.error(error),
  },
});

Option	Type	Default	Notes
`apiKey`	`string`	required	API key in `whcc_...` format. Often read from `process.env.WHK_API_KEY`.
`baseUrl`	`string`	`https://webhooks.cc`	API base URL
`webhookUrl`	`string`	`https://go.webhooks.cc`	receiver base URL used by `endpoints.send()`
`timeout`	`number`	`30000`	request timeout in milliseconds
`retry`	`RetryOptions`	`1` attempt	retries transient failures (see below)
`hooks`	`ClientHooks`	none	lifecycle callbacks for request logging
`emailDomain`	`string`	`mailhooks.cc`	domain `emails.address()` builds addresses on

With retry, GET, PUT and DELETE calls are repeated after a network error, a timeout or a status in retryOn (429, 500, 502, 503 and 504 by default), and any call after a 429, which the API sends before doing anything. A POST or PATCH that failed any other way is not repeated: it may have gone through, and a second endpoints.create() would leave an extra endpoint. Nor is requests.clear() without before, whose repeat would also delete what arrived in between.

API overview

client.endpoints: create, list, get, update, delete, send, sendTemplate
client.requests: list, listPaginated, get, waitFor, waitForAll, subscribe, replay, search, count, clear, export
client.emails: address, list, get, latest, waitFor, waitForAll, sendTest, toJson
client.forwarding: configure, secret, rotateSecret, test, deliveries, summary, requestDeliveries, redeliver, redeliverFailed
client.templates: listProviders, get
client.teams: list, members, share, unshare, invite, invites.list, invites.accept, invites.decline
top-level client methods: usage(), sendTo(), buildRequest(), flow(), describe()

Endpoints

Create persistent or ephemeral endpoints. You can also attach a mock response at creation time.

const endpoint = await client.endpoints.create({
  name: "billing-webhooks",
  expiresIn: "12h",
  mockResponse: {
    status: 202,
    body: '{"queued":true}',
    headers: { "x-webhooks-cc": "mock" },
  },
});

const fetched = await client.endpoints.get(endpoint.slug);
console.log(fetched.isEphemeral, fetched.expiresAt);

await client.endpoints.update(endpoint.slug, {
  name: "billing-webhooks-renamed",
  mockResponse: null,
});

Answer differently per request with response rules, and echo the request with placeholders. previewResponse shows what a captured request would get back without sending anything:

await client.endpoints.update(endpoint.slug, {
  responseRules: [
    {
      name: "Payment failed",
      conditions: [{ field: "body_path", op: "eq", path: "type", value: "invoice.payment_failed" }],
      response: { status: 422, body: '{"event": "{{ json.id }}"}', headers: {} },
    },
  ],
  mockResponse: { status: 200, body: '{"id": "{{ uuid }}"}', headers: {} },
});

const preview = await client.endpoints.previewResponse(endpoint.slug);
console.log(preview.rule?.index, preview.response?.body);

Send plain test requests through the hosted receiver:

await client.endpoints.send(endpoint.slug, {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: { event: "invoice.paid" },
});

Requests

List, paginate, wait, stream, replay, export, and clear captured requests.

const recent = await client.requests.list(endpoint.slug, {
  limit: 50,
  since: Date.now() - 60_000,
  kind: "http", // or "email"; omit for both
});

const page1 = await client.requests.listPaginated(endpoint.slug, { limit: 100 });
const page2 = page1.cursor
  ? await client.requests.listPaginated(endpoint.slug, { limit: 100, cursor: page1.cursor })
  : { items: [], hasMore: false };

const firstMatch = await client.requests.waitFor(endpoint.slug, {
  timeout: "20s",
  match: matchHeader("stripe-signature"),
});

const allMatches = await client.requests.waitForAll(endpoint.slug, {
  count: 3,
  timeout: "30s",
  match: matchMethod("POST"),
});

for await (const request of client.requests.subscribe(endpoint.slug, { reconnect: true })) {
  console.log(request.method, request.path);
}

subscribe() streams over SSE. The server rotates every stream connection after 30 minutes: it sends a timeout event and closes. With reconnect: true the client follows that rotation transparently, reconnecting immediately, resuming from the last received request, and deduplicating replayed events, so the loop above runs until you break out of it, abort the signal, the timeout expires, or the endpoint is deleted. Rotations do not count against maxReconnectAttempts (default 5), which only limits recovery from unexpected stream ends and transient errors (with exponential backoff from reconnectBackoffMs). Without reconnect, the loop ends at the first rotation, after at most 30 minutes.

An idle watchdog (idleTimeout, default "90s", three server keepalive intervals) detects half-open sockets: if nothing arrives within that window while waiting, the connection is dropped. With reconnect: true it is reconnected (counted as a reconnect attempt, with backoff); without it, the iterator throws TimeoutError. Pass idleTimeout: 0 to disable the watchdog.

for await (const request of client.requests.subscribe(endpoint.slug, {
  reconnect: true,
  maxReconnectAttempts: 10,
  idleTimeout: "2m",
  onReconnect: (attempt) => console.warn(`stream reconnect #${attempt}`),
})) {
  console.log(request.method, request.path);
}

Replay, export, and clear requests:

await client.requests.replay(firstMatch.id, "http://localhost:3001/webhooks");

const curlExport = await client.requests.export(endpoint.slug, {
  format: "curl",
  limit: 10,
});

const harExport = await client.requests.export(endpoint.slug, {
  format: "har",
  since: Date.now() - 3_600_000,
});

await client.requests.clear(endpoint.slug, { before: "24h" });

Search and count use the retained request store rather than the live endpoint request table:

const retained = await client.requests.search({
  slug: endpoint.slug,
  q: "checkout.session.completed",
  from: "7d",
  limit: 20,
});

const total = await client.requests.count({
  slug: endpoint.slug,
  q: "checkout.session.completed",
  from: "7d",
});

search() returns SearchResult[]. Their id field is synthetic and is not valid for requests.get() or requests.replay().

requests.list(), listPaginated(), search() and count() take kind: "http" | "email". waitFor() and waitForAll() look back five minutes by default, so a request that arrived just before the call is found; pass since to change that.

Emails

Every endpoint on an account also receives email at <slug>@mailhooks.cc, and at <slug>+<tag>@mailhooks.cc for any tag. Guest endpoints receive none. A captured email is a request with kind: "email", method: "EMAIL", the recipient address as path, the raw message as body, and the parsed message as email (typed EmailRequest). Each email counts as one request against your quota.

Give each test run its own tag, wait for its email, and pull out the code or link:

import { extractCode, extractLink } from "@webhooks-cc/sdk";

const runId = `signup-${Date.now()}`;
await yourApp.signUp({ email: client.emails.address(endpoint.slug, runId) });

const email = await client.emails.waitFor(endpoint.slug, { tag: runId, timeout: "60s" });
console.log(email.email.subject, email.email.from[0]?.address);

const code = extractCode(email); // "482913", or null
const link = extractLink(email); // the confirm, verify, reset or sign-in link, or null

client.emails methods:

address(endpointOrSlug, tag?): the address, optionally tagged. Pass the endpoint object to use the address the server reports; a slug uses the emailDomain client option
list(slug, { tag, subject, from, to, limit, since }): emails newest first. limit (default 50) is how many of the newest emails are fetched before the filters apply
get(requestId): one email; throws NotFoundError for anything else
latest(slug, criteria): the newest matching email among the 100 newest, or null
waitFor(slug, { ...criteria, timeout, pollInterval, since, match }): polls until a matching email arrives (defaults: 60 s timeout, 1 s interval, looking back five minutes)
waitForAll(slug, { count, ...options }): polls until count matching emails arrived, oldest first
sendTest(slug, { tag? }): delivers a sample email with a six-digit code and a link. It counts as one request and skips SMTP, so no sender checks run on it
toJson(email, { endpoint?, includeExtracts? }): the email.received JSON forwarding would post

The criteria are tag (exact and case-sensitive; null matches untagged mail), subject (a substring or a RegExp), from and to (an address, compared case-insensitively, or a RegExp tested against Name <address>). to also matches the address the email was delivered to.

extractFromEmail(email.email) returns every code and link found ({ codes, links }). extractLink(email) returns the confirm, verify, reset or sign-in link when there is one, otherwise the first link worth keeping; pass { actionOnly: true } to accept only an action link.

matchEmail(criteria) does the same filtering as a matcher for requests.waitFor() or captureDuring(), and isEmailRequest(request) narrows a request to EmailRequest. Requests from requests.subscribe() carry kind but not the parsed email; fetch it with client.emails.get(request.id). requests.replay() throws for emails, requests.export() skips them, and provider detection ignores them.

The @webhooks-cc/sdk/email entry point exports the email types, extractCode, extractLink, extractFromEmail, htmlToText, buildEmailJson, emailAddress and isValidEmailTag. It has no network code, so it fits in a browser bundle.

Forwarding

Forwarding sends what an endpoint captures to up to 10 destinations: your servers, Slack or Discord channels, or tools such as Zapier and n8n. Each destination has its own kinds, conditions, format (as received, signed JSON, your own JSON with {{ placeholders }}, or a chat message), throttle, delay and signing secret, and is queued, retried and logged. Only the endpoint's owner can manage it.

// Only paid invoices, as the JSON your tool wants.
const zap = await client.destinations.create(endpoint.slug, {
  url: "https://hooks.zapier.com/hooks/catch/123/abc",
  email: false,
  filter: { conditions: [{ field: "body_path", op: "eq", path: "type", value: "invoice.paid" }] },
  format: "template",
  bodyTemplate: {
    invoice: "{{ json.data.object.id }}",
    amount: "{{ json.data.object.amount_paid }}",
  },
});

// What it would send for the newest request, without sending it.
const preview = await client.destinations.preview(endpoint.slug, { destinationId: zap.id });
console.log(preview.filterPasses, preview.delivery?.body);

// Send one for real, and read its signing secret for your handler.
const test = await client.destinations.test(endpoint.slug, zap.id);
const secret = await client.destinations.secret(endpoint.slug, zap.id); // "whsec_..."

client.destinations also has list(slug, { summary }), get, update (only the fields you pass), delete, reorder and rotateSecret. A Slack or Discord destination with format: "chat" takes an optional messageTemplate, and throttleSeconds: 1 makes it a heads-up; delaySeconds (up to an hour) makes any destination a callback that arrives later.

client.forwarding manages the endpoint's primary destination with configure(), secret(), rotateSecret() and test(), and reads the log of all of them: deliveries(slug, { limit, status, destinationId, before }), summary(slug), requestDeliveries(requestId) (every try of one request), redeliver(requestId, { destinationId }) and redeliverFailed(slug, { destinationId }).

In your handler, verify relayed requests with verifyRelayedRequest() (the webhooks-cc-signature header), signed JSON with verifyForwardedRequest() or verifyForwardedEmail(), and your own JSON with verifyForwardedJson(). For a forwarded email, verifyForwardedEmail() checks the Standard Webhooks signature and that the timestamp is within five minutes, then returns the typed event. Pass the raw body (string, Uint8Array/Buffer or ArrayBuffer) and the headers as a Fetch Headers, a plain object such as Express's req.headers, or name and value pairs:

import { verifyForwardedEmail, WebhookVerificationError } from "@webhooks-cc/sdk";

export async function POST(request: Request) {
  try {
    const event = await verifyForwardedEmail(
      await request.text(),
      request.headers,
      process.env.FORWARD_SECRET!
    );
    console.log(event.data.subject, event.data.codes);
    return new Response(null, { status: 204 });
  } catch (error) {
    if (error instanceof WebhookVerificationError) {
      // error.code: missing_headers | timestamp_out_of_range | invalid_signature | invalid_payload
      return new Response(error.message, { status: error.code === "invalid_payload" ? 400 : 401 });
    }
    throw error;
  }
}

To test a handler on your machine without forwarding, post a captured email to it, signed with your secret:

const email = await client.emails.latest(endpoint.slug);
if (email) {
  await client.sendTo("http://localhost:3000/hooks/email", {
    provider: "standard-webhooks",
    secret: process.env.FORWARD_SECRET!,
    body: client.emails.toJson(email),
  });
}

Templates, sendTo, and buildRequest

The SDK can generate provider-shaped webhook payloads (signed where the provider uses a shared secret or public test key flow) for:

stripe
github
shopify
twilio
slack
paddle
linear
sendgrid
clerk
discord
vercel
gitlab
typeform
standard-webhooks
meta
lemonsqueezy
coinbase-commerce
razorpay
cal
intercom
telegram
square
hubspot
mailgun
calendly
mux
sentry
bitbucket
docusign
adyen
paypal
plaid
resend
workos

sendgrid, discord, paypal, and plaid templates are intentionally not shared-secret signed: SendGrid uses IP allowlisting, Discord/PayPal signatures require provider-owned private keys, and Plaid verification uses Plaid JWT/JWK lookup.

Inspect the static provider metadata:

const providers = client.templates.listProviders();
const stripe = client.templates.get("stripe");

console.log(providers);
console.log(stripe.signatureHeader, stripe.templates);

If you prefer a static export, import TEMPLATE_METADATA from @webhooks-cc/sdk.

Send a signed provider template through a hosted endpoint:

await client.endpoints.sendTemplate(endpoint.slug, {
  provider: "slack",
  template: "slash_command",
  secret: process.env.SLACK_SIGNING_SECRET!,
});

Build or send a signed request directly to any URL:

const preview = await client.buildRequest("http://localhost:3001/webhooks", {
  provider: "stripe",
  template: "checkout.session.completed",
  secret: "whsec_test_123",
});

await client.sendTo("http://localhost:3001/webhooks", {
  provider: "github",
  template: "push",
  secret: "github_secret",
});

Signature verification

The SDK includes provider-specific verification helpers and a provider-agnostic verifySignature().

Provider-specific helpers such as verifyStripeSignature() and verifyDiscordSignature() are also exported.

Supported verification providers:

stripe
github
shopify
twilio
slack
paddle
linear
clerk
discord
vercel
gitlab
typeform
standard-webhooks
meta
lemonsqueezy
coinbase-commerce
razorpay
cal
intercom
telegram
square
hubspot
mailgun
calendly
mux
sentry
bitbucket
docusign
adyen
paypal
resend
workos

sendgrid and plaid are template-only for verification: SendGrid uses IP allowlisting, and Plaid JWT/JWK verification requires Plaid API credentials.

import { isDiscordWebhook, verifySignature } from "@webhooks-cc/sdk";

if (isDiscordWebhook(request)) {
  const result = await verifySignature(request, {
    provider: "discord",
    publicKey: process.env.DISCORD_PUBLIC_KEY!,
  });

  console.log(result.valid);
}

For Twilio, Square, and HubSpot, pass the original signed URL. HubSpot v3 also signs the HTTP method, so pass method too:

const result = await verifySignature(request, {
  provider: "twilio",
  secret: process.env.TWILIO_AUTH_TOKEN!,
  url: "https://example.com/webhooks/twilio",
});

// HubSpot v3 signs `method + url + body + timestamp` and rejects stale timestamps
const hubspot = await verifySignature(request, {
  provider: "hubspot",
  secret: process.env.HUBSPOT_CLIENT_SECRET!,
  url: "https://example.com/webhooks/hubspot",
  method: "POST",
});

Mailgun is the exception with no signature header: it embeds signature.{timestamp,token,signature} in the request body, so verifyMailgunSignature reads the body directly and never throws on malformed input.

SendGrid uses IP allowlisting rather than cryptographic signature verification.

Request detection helpers are exported for every supported provider:

isStripeWebhook        isGitHubWebhook         isShopifyWebhook     isSlackWebhook
isTwilioWebhook        isPaddleWebhook         isLinearWebhook      isSendGridWebhook
isClerkWebhook         isDiscordWebhook        isVercelWebhook      isGitLabWebhook
isTypeformWebhook      isStandardWebhook       isMetaWebhook        isLemonSqueezyWebhook
isCoinbaseCommerceWebhook  isRazorpayWebhook   isCalWebhook         isIntercomWebhook
isTelegramWebhook      isSquareWebhook         isHubSpotWebhook     isMailgunWebhook
isCalendlyWebhook      isMuxWebhook            isSentryWebhook      isBitbucketWebhook
isDocuSignWebhook      isAdyenWebhook          isPayPalWebhook      isPlaidWebhook
isResendWebhook        isWorkOSWebhook

Payload schemas

Generate types for a handler from captured requests: TypeScript interfaces, Zod schemas, Pydantic models, or JSON Schema. Pass several requests of the same event: a field missing from some samples becomes optional, one that is sometimes null becomes nullable.

import { generateRequestSchema } from "@webhooks-cc/sdk";

const requests = await client.requests.list(endpoint.slug, { limit: 20 });
const { code, samples } = generateRequestSchema(requests, {
  format: "zod", // "typescript" (default), "zod", "pydantic", or "json-schema"
  name: "InvoicePaidEvent",
});

generatePayloadSchema(values, options) does the same from parsed values. Both work offline, and @webhooks-cc/sdk/schema exports them without the client, for browser bundles.

Matchers, parsing, and diffing

Use matchers with waitFor() or waitForAll():

import {
  matchAll,
  matchBodySubset,
  matchContentType,
  matchHeader,
  matchPath,
  matchQueryParam,
} from "@webhooks-cc/sdk";

const request = await client.requests.waitFor(endpoint.slug, {
  match: matchAll(
    matchPath("/webhooks/stripe"),
    matchHeader("stripe-signature"),
    matchContentType("application/json"),
    matchQueryParam("tenant", "acme"),
    matchBodySubset({ type: "checkout.session.completed" })
  ),
});

matchAny(), matchBodyPath(), and matchJsonField() are available when you need looser matching. matchEmail({ tag, subject, from, to }) matches captured emails; see Emails.

Parse request bodies and diff captures:

import { diffRequests, extractJsonField, parseBody, parseFormBody } from "@webhooks-cc/sdk";

const parsed = parseBody(request);
const form = parseFormBody(request);
const eventType = extractJsonField<string>(request, "type");

const diff = diffRequests(previousRequest, request, {
  ignoreHeaders: ["date", "x-request-id"],
});

console.log(parsed, form, eventType, diff.matches);

Testing helpers

@webhooks-cc/sdk/testing adds a small test-oriented layer:

withEndpoint()
withEphemeralEndpoint()
captureDuring()
captureEmailDuring()
assertRequest()

import { matchHeader, WebhooksCC } from "@webhooks-cc/sdk";
import { assertRequest, captureDuring } from "@webhooks-cc/sdk/testing";

const client = new WebhooksCC({ apiKey: process.env.WHK_API_KEY! });

const [request] = await captureDuring(
  client,
  async (endpoint) => {
    await yourApp.registerWebhook(endpoint.url!);
    await yourApp.triggerCheckout();
  },
  {
    expiresIn: "1h",
    timeout: "20s",
    match: matchHeader("stripe-signature"),
  }
);

assertRequest(
  request,
  {
    method: "POST",
    bodyJson: { type: "checkout.session.completed" },
  },
  { throwOnFailure: true }
);

captureEmailDuring() creates a temporary endpoint, runs your action with its email address, waits for the email, and deletes the endpoint:

import { extractCode } from "@webhooks-cc/sdk";
import { captureEmailDuring } from "@webhooks-cc/sdk/testing";

const [email] = await captureEmailDuring(
  client,
  async (address) => {
    await yourApp.signUp({ email: address });
  },
  { subject: "Confirm your email", timeout: "30s" }
);

console.log(extractCode(email));

It takes the email criteria (tag, subject, from, to), count (default 1), timeout (default 60 s), pollInterval, match, and the options of endpoints.create().

Flow builder

client.flow() composes the common test sequence into one chain: create endpoint, optionally set a mock, send a request, wait for capture, verify the signature, replay the request, and clean up.

const result = await client
  .flow()
  .createEndpoint({ expiresIn: "1h" })
  .sendTemplate({
    provider: "github",
    template: "push",
    secret: "github_secret",
  })
  .waitForCapture({ timeout: "15s" })
  .verifySignature({
    provider: "github",
    secret: "github_secret",
  })
  .cleanup()
  .run();

console.log(result.request?.id, result.verification?.valid, result.cleanedUp);

Teams

A key has exactly the team access of the account it belongs to. Endpoints shared with you through a subscribed team appear in endpoints.list() with fromTeam set and work with every request method by slug except requests.clear, which stays with the owner. The teams namespace manages the teams themselves:

const teams = await client.teams.list();
// [{ id, name, role, seats, requestsUsed, requestLimit, periodEnd, suspended, ... }]

// Only endpoints tied to one team (id or name), shared either way
const payments = await client.endpoints.list({ team: "Payments" });

// Owner-only: share an endpoint you own, by slug. Its requests then bill the team pool.
await client.teams.share(teams[0].id, "my-stripe");
await client.teams.unshare(teams[0].id, "my-stripe");

const { members, pendingInvites } = await client.teams.members(teams[0].id);

// Invites: sending one emails the address; accepting claims a paid seat.
await client.teams.invite(teams[0].id, "dev@example.com");
const invites = await client.teams.invites.list();
await client.teams.invites.accept(invites[0].id);

Usage and self-description

Check quota state from code:

const usage = await client.usage();
console.log(usage.used, usage.limit, usage.remaining, usage.plan);

Ask the client what it supports without making an API call:

const description = client.describe();
console.log(description.requests.waitForAll);

Errors

API failures throw typed errors:

WebhooksCCError
UnauthorizedError
NotFoundError
TimeoutError (also thrown by requests.subscribe() when the idle watchdog trips without reconnect)
RateLimitError

verifyForwardedEmail() throws WebhookVerificationError, whose code is missing_headers, timestamp_out_of_range, invalid_signature or invalid_payload.

ApiError is still exported as a legacy alias of WebhooksCCError.

License

MIT

Keywords

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Package last updated on 25 Oct 2026

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