Stumbled on a weird bug today with the Entity Lookup action in our AppFoundry bot flow. The request hits the custom API endpoint successfully, but the Architect returns a 500 Internal Server Error immediately after the HTTP request completes, despite valid JSON payload.
Error: Failed to process entity lookup. Response body is not parseable or schema mismatch detected on field 'customer_tier'.
Verified the payload matches the schema exactly. Any ideas on why the platform API rejects this post-lookup?
Schema validation in Architect is stricter than standard JSON parsing. If the API returns null for a non-nullable field like customer_tier, the flow engine throws a 500 instead of a clean error. Check the raw response body during the test.
Rate limiting on custom endpoints can cause partial responses or timeouts that look like schema errors. Ensure your JMeter thread group doesn’t exceed the endpoint’s configured rate limit.
WebSocket backpressure might be dropping the response packet before Architect processes it. Increase the idle_timeout in your JMeter HTTP Request sampler to allow the full handshake to complete.
Verify the Content-Type header is explicitly application/json. Architect sometimes fails to parse responses if the header is missing or set to text/plain.
Add a retry loop in the flow with a small delay (500ms). This often masks transient 500s caused by backend scaling events during load spikes.