n8n-io/n8n · error · GatewayAuthError

Gateway rejected token: ${status} ${body}

Error message

Gateway rejected token: ${status} ${body}

What it means

GatewayAuthError thrown by uploadCapabilities() when the instance-ai gateway returns 401 or 403 for the X-Gateway-Key pairing token. The error has name 'GatewayAuthError', .status, and .body fields. This is an authentication failure at the gateway init endpoint — the pairing token is invalid, expired, or revoked.

Source

Thrown at packages/@n8n/computer-use/src/gateway-client.ts:316

		const url = `${this.options.url}/rest/instance-ai/gateway/init`;
		const headers = new Headers();
		headers.set('Content-Type', 'application/json');
		headers.set('X-Gateway-Key', this.apiKey);
		const response = await fetch(url, {
			method: 'POST',
			headers,
			body: JSON.stringify({
				rootPath: this.dir,
				tools,
				hostIdentifier: `${os.userInfo().username}@${os.hostname()}`,
				toolCategories: this.activeToolCategories,
			}),
		});

		if (!response.ok) {
			const text = await response.text();
			if (response.status === 401 || response.status === 403) {
				throw new GatewayAuthError(response.status, text);
			}
			throw new Error(`Failed to upload capabilities: ${response.status} ${text}`);
		}

		// If the server returned a session key, switch to it for all subsequent requests
		// n8n wraps controller responses in { data: ... }
		const body = (await response.json()) as { data: { ok: boolean; sessionKey?: string } };
		if (body.data.sessionKey) {
			this.sessionKey = body.data.sessionKey;
			logger.debug('Pairing token consumed, switched to session key');
		}

		logger.debug('Capabilities uploaded', { toolCount: tools.length });
	}

	private connectSSE(): void {
		const url = `${this.options.url}/rest/instance-ai/gateway/events`;

View on GitHub (pinned to 5ac6606e81)

Solutions

1. Re-run the pairing flow to obtain a fresh gateway key
2. Verify the gateway URL (options.url) matches the target n8n instance
3. Confirm Instance AI / MCP gateway is enabled on the n8n server
4. Check the n8n server logs for gateway auth rejection details

import { GatewayAuthError } from './gateway-client';

function isGatewayAuthError(e: unknown): e is GatewayAuthError {
  return e instanceof GatewayAuthError;
}

try {
  await gatewayClient.start();
} catch (e) {
  if (e instanceof GatewayAuthError) {
    // e.status (401 or 403), e.body (server response text)
    printAuthFailure(e);
    // Re-pair to get a fresh token
    await rePairGateway();
  } else {
    throw e;
  }
}

When it happens

Trigger: The pairing token (apiKey) is expired, revoked, or was generated for a different instance. The gateway URL points to a different n8n instance. Instance AI / MCP gateway is disabled on the server. The server restarted and invalidated pairing tokens.

Common situations: Long gap between pairing and tool registration causing token expiry, wrong gateway URL in config, instance restart, clipboard copy error on the token.

Related errors

• Failed to upload capabilities: ${response.status} ${text}
• Credential creation failed: ${res.status} ${text}
• No suspended run found for runId: ${this.runId}
• User permanently denied access to ${resource.toolGroup}: ${r
• GATEWAY_CONFIRMATION_REQUIRED::${JSON.stringify({ toolGroup:

AI-assisted analysis of n8n-io/n8n@5ac6606e81 (2026-08-12). Data as JSON: /api/errors/2858c1968d2e3ac9. Report an issue: GitHub.