Codex SSE response headers timed out after ${httpTimeoutMs}m

Error message

Codex SSE response headers timed out after ${httpTimeoutMs}ms

What it means

Error "Codex SSE response headers timed out after ${httpTimeoutMs}ms" thrown in earendil-works/pi.

Source

Thrown at packages/ai/src/api/openai-codex-responses.ts:400

			for (let attempt = 0; attempt <= maxRetries; attempt++) {
				if (options?.signal?.aborted) {
					throw new Error("Request was aborted");
				}

				try {
					const headerTimeoutSignal =
						httpTimeoutMs !== undefined && httpTimeoutMs > 0 ? AbortSignal.timeout(httpTimeoutMs) : undefined;
					const combinedSignal = combineAbortSignals([options?.signal, headerTimeoutSignal]);
					try {
						response = await (options?.fetch ?? globalThis.fetch)(resolveCodexUrl(model.baseUrl), {
							method: "POST",
							headers: sseHeaders,
							body: sseBody,
							signal: combinedSignal.signal,
						});
					} catch (error) {
						if (headerTimeoutSignal?.aborted && !options?.signal?.aborted) {
							throw new Error(`Codex SSE response headers timed out after ${httpTimeoutMs}ms`);
						}
						throw error;
					} finally {
						combinedSignal.cleanup();
					}
					await options?.onResponse?.(
						{ status: response.status, headers: headersToRecord(response.headers) },
						model,
					);

					if (response.ok) {
						break;
					}

					const errorText = await response.text();
					if (attempt < maxRetries && isRetryableError(response.status, errorText)) {
						const retryAfterDelayMs = getRetryAfterDelayMs(response.headers);
						const delayMs =

View on GitHub (pinned to 4af9d21d3b)

Solutions

Increase httpTimeoutMs, or check network and proxy latency to the SSE endpoint.

When it happens

Trigger: Thrown at packages/ai/src/api/openai-codex-responses.ts:400 when the library encounters an invalid state.

Common situations: See trigger scenarios.

Understand the failure class

Timeouts: ETIMEDOUT, deadlines, and hung requests — what actually expires when a request times out.

AI-assisted analysis of earendil-works/pi@4af9d21d3b (2026-08-24). Data as JSON: /api/errors/d8407c5e786e05e6. Report an issue: GitHub.