# Intermittent ERR\_STREAM\_PREMATURE\_CLOSE on create-retell-llm / update-retell-llm (connection dropped before response body) **URL:** \ **Category:** Support Help\ **Tags:** bug\ **Created:** [June 22, 2026, 9:27pm UTC](https://community.retellai.com/t/intermittent-err-stream-premature-close-on-create-retell-llm-update-retell-llm-connection-dropped-before-response-body/3163 "2026-06-22T21:27:00Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![david4](https://yyz2.discourse-cdn.com/flex008/user_avatar/community.retellai.com/david4/32/1012_2.png) [@david4](https://community.retellai.com/u/david4)\ **Post date:** [June 22, 2026, 9:27pm UTC](https://community.retellai.com/t/intermittent-err-stream-premature-close-on-create-retell-llm-update-retell-llm-connection-dropped-before-response-body/3163/1 "2026-06-22T21:27:01Z")
Summary Our backend is getting connection failures when calling your LLM management API. The HTTP connection is being closed by your server before the response body is fully delivered, so our Node.js fetch client throws ERR\_STREAM\_PREMATURE\_CLOSE (“Premature close”). This surfaces to our users as 500 errors when creating/updating voice agents. Affected endpoints - POST [https://api.retellai.com/create-retell-llm](https://api.retellai.com/create-retell-llm) - PATCH/POST [https://api.retellai.com/update-retell-llm/{llm\_id}](https://api.retellai.com/update-retell-llm/%7Bllm_id%7D) (e.g. llm\_69ef2a8915bbec9c75fbb365ff03) Exact error signature Invalid response body while trying to fetch /create-retell-llm close errno: ERR\_STREAM\_PREMATURE\_CLOSE code: ERR\_STREAM\_PREMATURE\_CLOSE type: system No HTTP status code is returned — the socket is closed mid-response, so there is no 4xx/5xx from your side, just a truncated/aborted response stream. Timeline (intermittent bursts, 2026-06-22) - ~14:00–14:56 UTC (09:00–09:56 COT): ~30 failures, then recovered. - Quiet period (no errors) until ~19:38 UTC. - 19:38 UTC (14:38 COT): failures resume — first occurrence at 2026-06-22 19:38:27 UTC. - 20:00–20:30 UTC: 6 failures. - 20:30–21:00 UTC (15:30–16:00 COT): 34 failures — and climbing at time of report (20:56 UTC). - Last 30 min split: 18× on create-retell-llm, 14× on update-retell-llm. Other notes for your investigation - The failures hit multiple of our backend instances (different hostnames/PIDs), so this is not a single bad client/pod on our end. - 100% of these errors are ERR\_STREAM\_PREMATURE\_CLOSE — no timeouts, no DNS/TLS errors, no 4xx/5xx. The request is sent and accepted; the response stream just terminates early. - Pattern is intermittent (two separate bursts with a clean recovery in between), which points to server-side connection resets rather than a hard outage. What we’d like from you 1. Confirm whether your create-retell-llm / update-retell-llm services experienced connection drops / instability in the windows above (UTC). 2. Any recommended client settings on our side (keep-alive timeout, connection reuse, idempotency/retry guidance for these endpoints) to mitigate premature-close on transient resets. Raw sample log line {“level”:50,“time”:1782157107943,“component”:“VoiceAgentCrudController”,“error”:{“message”:“Invalid response body while trying to fetch /update-retell-llm/llm\_69ef2a8915bbec9c75fbb365ff03: Premature close”,“type”:“system”,“errno”:“ERR\_STREAM\_PREMATURE\_CLOSE”,“code”:“ERR\_STREAM\_PREMATURE\_CLOSE”},“msg”:“voice\_agent.crud\_internal\_error”} ---
**Author:** ![Shah-Fazal](https://yyz2.discourse-cdn.com/flex008/user_avatar/community.retellai.com/shah-fazal/32/2522_2.png) [@Shah-Fazal](https://community.retellai.com/u/Shah-Fazal)\ **Post date:** [June 22, 2026, 10:09pm UTC](https://community.retellai.com/t/intermittent-err-stream-premature-close-on-create-retell-llm-update-retell-llm-connection-dropped-before-response-body/3163/2 "2026-06-22T22:09:15Z")
@david4 checking with the team ---
**Author:** ![david4](https://yyz2.discourse-cdn.com/flex008/user_avatar/community.retellai.com/david4/32/1012_2.png) [@david4](https://community.retellai.com/u/david4)\ **Post date:** [June 23, 2026, 4:24am UTC](https://community.retellai.com/t/intermittent-err-stream-premature-close-on-create-retell-llm-update-retell-llm-connection-dropped-before-response-body/3163/3 "2026-06-23T04:24:04Z")
Any news? This is affecting our production environment with users ---
**Author:** ![Shah-Fazal](https://yyz2.discourse-cdn.com/flex008/user_avatar/community.retellai.com/shah-fazal/32/2522_2.png) [@Shah-Fazal](https://community.retellai.com/u/Shah-Fazal)\ **Post date:** [June 24, 2026, 12:47pm UTC](https://community.retellai.com/t/intermittent-err-stream-premature-close-on-create-retell-llm-update-retell-llm-connection-dropped-before-response-body/3163/4 "2026-06-24T12:47:06Z")
Hey @david4 we’re looking into this. In the meantime for mitigation please try: - Retry: treat `ERR_STREAM_PREMATURE_CLOSE` (and any socket close with no HTTP status) as a retryable transport error. Exponential backoff with jitter, cap ~3–5 attempts. - Keep-alive: set your Node HTTP agent’s `keepAliveTimeout` strictly lower than any upstream idle timeout in your path so the client retires pooled sockets first. We’re separately auditing our server-side defaults; until that ships, lowering the client side is the safer half of the race. - PATCH /update-retell-llm: naturally idempotent at the resource level. Two safe retry patterns: (a) omit `If-Match` for blind retry — same body produces the same result; (b) re-GET to refresh the ETag and retry, accepting a possible 412 if a concurrent writer landed in between. - POST /create-retell-llm: NOT idempotent — `llm_id` is server-generated inside the handler, so a blind retry can produce a duplicate if the first request actually persisted before the socket closed. On premature-close, call `GET /list-retell-llms` and reconcile by a client-side correlator (e.g. a recognizable field you set in the LLM config) before retrying. Thank You