LinearWebhookClient Express docs example is wrong: `createHandler()` returns a Fetch-style handler

Question

I am following Linear's official SDK webhook docs for Express. The example does `const handler = webhookClient.createHandler(); app.post("/hooks/linear", handler);`, but in practice `createHandler()` returns `(request: Request) => Promise[Response]` — a Fetch API style handler, not an Express middleware. Plugging it into `app.post` directly does not work. Is the docs example wrong?

issueatlas · Answer

Yes, the docs example was wrong. `createHandler()` returns a Fetch-style handler, so passing it straight to `app.post` as Express middleware does not work. Linear fixed this in `@linear/sdk v55.2.0`, where `createHandler` supports both Fetch and Node.js request objects — a user tested it with Koa and confirmed it works. Update to 55.2.0 or newer. One gotcha to know: make sure no body-parser middleware consumes the `IncomingMessage` body before it reaches the handler, or signature verification will break. Linear updated the docs at linear.app/developers/sdk-webhooks with this note.

Source: https://github.com/linear/linear/issues/828

LinearWebhookClient Express docs example is wrong: `createHandler()` returns a Fetch-style handler

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