hcengineering/platform · error

Unknown method

Error message

Unknown method

What it means

The /rpc/:id endpoint looks up the requested procedure in its registered methods map. If request.body.method is not registered (or the body is not a valid RpcRequest), the server responds HTTP 400 with {error:'Unknown method'}.

Source

Thrown at server/collaborator/src/server.ts:182

    }

    const documentId = req.params.id
    if (documentId === undefined || documentId === '') {
      const response: RpcErrorResponse = {
        error: 'Missing document id'
      }
      res.status(400).send(response)
      return
    }

    const request = req.body as RpcRequest

    const method = methods[request.method]
    if (method === undefined) {
      const response: RpcErrorResponse = {
        error: 'Unknown method'
      }
      res.status(400).send(response)
      return
    }

    const context = await getContext(rawToken, token)

    rpcCtx.info('rpc', { method: request.method, connectionId: context.connectionId, mode: token.extra?.mode ?? '' })
    await rpcCtx.with(
      '/rpc',
      {
        source: token.extra?.service ?? '🤦‍♂️user',
        method: request.method
      },
      async (ctx) => {
        try {
          const response: RpcResponse = await rpcCtx.with(request.method, {}, (ctx) => {
            return method(ctx, context, documentId, request.payload, { hocuspocus, storageAdapter, transformer })
          })
          res.status(200).send(response)

View on GitHub (pinned to 63e28dc964)

Solutions

1. Use a method name registered on the collaborator server (verify against the methods map).
2. Send Content-Type: application/json and a body of the form {method, params} so request.method parses correctly.
3. Align client and server versions so the called method exists in the deployed build.

Example fix

// before
body: JSON.stringify({ name: 'push', params })
// after
body: JSON.stringify({ method: 'push', params }),
headers: { 'Content-Type': 'application/json' }

const KNOWN_METHODS = ['push', 'pull', 'ping'] // must mirror the server's methods map
function isKnownMethod(body: unknown): body is { method: string; params?: unknown } {
  return typeof body === 'object' && body !== null && 'method' in body &&
    typeof (body as any).method === 'string' && KNOWN_METHODS.includes((body as any).method)
}

function isRpcRequest(x: unknown): x is RpcRequest {
  return typeof x === 'object' && x !== null && typeof (x as RpcRequest).method === 'string'
}

if (!isKnownMethod(requestBody)) {
  throw new Error(`Unknown RPC method: ${JSON.stringify(requestBody)}`)
}
const res = await postRpc(url, requestBody)
if (res.status === 400) {
  const { error } = await res.json()
  if (error === 'Unknown method') throw new Error('Method not registered on collaborator server')
}

When it happens

Trigger: POST /rpc/:id whose JSON body has a method field not present in the server's methods registry, or a missing/empty method field, or a body that is not JSON (request.method resolves to undefined).

Common situations: Client/server version skew (method renamed or not yet deployed); typos in method names; forgetting to set Content-Type: application/json so req.body is undefined.

Related errors

• Missing document id
• Failed to load server config
• getDisplayMedia not supported
• No screen access granted
• platform.status.BadRequest

AI-assisted analysis of hcengineering/platform@63e28dc964 (2026-08-29). Data as JSON: /api/errors/4700f93b4da808e2. Report an issue: GitHub.