@ai0x0/codex-ts

A TypeScript port of the codex-rs agent core — runs the Codex sampling loop (Responses API streaming + tool calls + auto-compaction) directly in Node or the browser, with no spawned process.

import { CodexThread } from "@ai0x0/codex-ts";

const thread = new CodexThread({
  apiKey: "…",
  baseUrl: "https://api.openai.com/v1",
  model: "gpt-5.4",
});

const turnId = await thread.submit({
  type: "UserInput",
  items: [{ type: "text", text: "hello" }],
});

for (;;) {
  const { msg } = await thread.nextEvent();
  if (msg.type === "AgentMessage") console.log(msg.event.message);
  if (msg.type === "TurnComplete") break;
}

Retries

Transient Responses failures are retried automatically with exponential backoff — mirrors codex-rs's stream retry loop (responses_retry.rs).

A failure is retried when it happens before any visible output has streamed and is transient:

• a network error (fetch rejects: connection reset, DNS, CORS-masked failure…);
• an HTTP 408, 409, 429, or any 5xx (e.g. a 502 during a deploy window);
• the SSE stream dropping before the first text delta.

A failure is not retried when:

• visible output has already streamed (a re-stream would duplicate text);
• the error is terminal — 4xx other than the above (e.g. 400, 401), or the turn was interrupted (AbortError);
• the retry budget (maxRetries) is exhausted.

Each retry waits an exponential backoff — 200ms × 2^(n-1) with ±10% jitter — honoring a server Retry-After header when present. A Warning event (Reconnecting... n/m) is emitted before each attempt so the UI can surface it.

Configuration

const thread = new CodexThread({
  apiKey: "…",
  model: "gpt-5.4",
  // Max retries for transient request/stream failures. Default: 5.
  // Pass 0 to disable retries entirely.
  maxRetries: 5,
});

| Option | Default | Meaning | | ------------ | ------- | ---------------------------------------------------------- | | maxRetries | 5 | Max retry attempts after the initial request. 0 disables. |

The same budget covers both the initial request and a stream that drops before any output; Retry-After overrides the computed backoff for that attempt.