Receive and verify eBay Notification API webhooks (Platform Notifications / Event Notifications). Use when setting up an eBay webhook endpoint, passing the endpoint challenge validation, debugging the x-ebay-signature ECDSA verification, fetching the public key with getPublicKey, or handling events like MARKETPLACE_ACCOUNT_DELETION.
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name
ebay-webhooks
description
Receive and verify eBay Notification API webhooks (Platform Notifications / Event Notifications). Use when setting up an eBay webhook endpoint, passing the endpoint challenge validation, debugging the x-ebay-signature ECDSA verification, fetching the public key with getPublicKey, or handling events like MARKETPLACE_ACCOUNT_DELETION.
How do I pass eBay's endpoint challenge validation (challenge_code)?
How do I verify the x-ebay-signature header (ECDSA)?
How do I use the eBay getPublicKey endpoint and cache the public key?
How do I handle MARKETPLACE_ACCOUNT_DELETION (marketplace account deletion / closure) notifications?
Why is my eBay signature verification failing?
How eBay Webhooks Differ From Most Providers
eBay does not use HMAC with a shared secret, and does not follow the
Standard Webhooks spec. Two distinct mechanisms are involved:
Endpoint challenge (one-time, on save) — When you register or update a
destination, eBay sends GET https://<your-endpoint>?challenge_code=....
You must respond with JSON where
the hex is the hash of exactly `challengeCode + verificationToken
HTTP 200
{"challengeResponse":"<hex>"}
SHA-256
endpoint` — in that order. The order is mandatory.
Per-notification signature (ECDSA) — Every notification carries an
x-ebay-signature header: a Base64-encoded JSON object with fields
alg, kid, signature, and digest. Use the kid to fetch the matching
public key via getPublicKey, then verify the ECDSA signature over the
raw request body. Cache the public key ~1 hour (keyed by kid).
Verification (core)
Endpoint challenge — deterministic SHA-256, no crypto keys needed:
const crypto = require('crypto');
functionchallengeResponse(challengeCode, verificationToken, endpoint) {
// ORDER IS MANDATORY: challengeCode + verificationToken + endpointconst hash = crypto.createHash('sha256');
hash.update(challengeCode);
hash.update(verificationToken);
hash.update(endpoint);
return hash.digest('hex'); // return as { challengeResponse: <hex> } with HTTP 200
}
Per-notification signature — ECDSA over the raw body, key fetched by kid:
asyncfunctionverifyEbaySignature(rawBody, signatureHeader, getPublicKey) {
if (!signatureHeader) returnfalse;
let sig;
try { sig = JSON.parse(Buffer.from(signatureHeader, 'base64').toString('utf8')); }
catch { returnfalse; } // { alg, kid, signature, digest }if (!sig.kid || !sig.signature) returnfalse;
const pem = awaitgetPublicKey(sig.kid); // cache ~1h, keyed by kidconst verifier = crypto.createVerify('sha1'); // eBay signs ECDSA with SHA-1
verifier.update(rawBody); // RAW body bytes — do not re-serialize
verifier.end();
try { return verifier.verify(pem, sig.signature, 'base64'); }
catch { returnfalse; }
}
For complete handlers with the challenge route, the getPublicKey fetch +
LRU cache, event dispatch, and tests, see:
Official SDK (Node.js): eBay publishes
event-notification-nodejs-sdk,
which wraps the exact algorithm above (EventNotificationSDK.process(...) for
signatures, validateEndpoint(...) for the challenge). The examples use a
transparent manual implementation so they are testable offline without the
OAuth call that getPublicKey requires — see
references/verification.md for the SDK path.
Common Event Types (Topics)
Topic
Triggered When
MARKETPLACE_ACCOUNT_DELETION
An eBay user closed their account / requested personal-data deletion. All developers must subscribe or opt out.
AUTHORIZATION_REVOCATION
A user revoked your app's authorization — stop making API calls on their behalf and clean up stored tokens.
ITEM_AVAILABILITY
Availability of a subscribed item changed
ITEM_PRICE_REVISION
Price of a subscribed item was revised
PRIORITY_LISTING_REVISION
A priority listing was revised
The topic arrives in the payload at metadata.topic. The full, current list of
topics (and the OAuth scopes needed to subscribe) is returned by the
getTopics
method — do not hard-code a list you cannot see.
Environment Variables
EBAY_VERIFICATION_TOKEN=your_verification_token # 32-80 chars, [A-Za-z0-9_-] only
EBAY_ENDPOINT=https://your-domain.com/webhooks/ebay # EXACT public URL eBay calls
EBAY_CLIENT_ID=your_app_id # App credentials (getPublicKey OAuth)
EBAY_CLIENT_SECRET=your_cert_id
EBAY_ENV=production # sandbox | production
Use the forwarding URL as EBAY_ENDPOINT and as the destination URL you
register with eBay. The endpoint URL used in the SHA-256 challenge hash must
be the exact URL eBay calls (the public tunnel URL, not localhost).
We recommend installing the webhook-handler-patterns skill alongside this one for handler sequence, idempotency, error handling, and retry logic. Key references (open on GitHub):
Handler sequence — Verify first, parse second, handle idempotently third
hookdeck-event-gateway - Webhook infrastructure that replaces your queue — guaranteed delivery, automatic retries, replay, rate limiting, and observability for your webhook handlers
