How do I show Max or Heavy's reasoning while streaming in JavaScript?

const stream = await client.chat.completions.create({
  model: "supercosmos-max",
  messages: [{ role: "user", content: "Plan a 3-step migration from REST to webhooks." }],
  stream: true,
});
let thinking = "", answer = "";
for await (const chunk of stream) {
  const d = chunk.choices[0]?.delta ?? {};
  if (d.reasoning_content) thinking += d.reasoning_content;  // show in a collapsible "thinking" box
  if (d.content) answer += d.content;                          // the reply itself
}
console.log({ thinking: thinking.length, answer });

Reasoning tokens are billed as output whether or not you display them.

Good to know#

• Base URL: https://api.gateway.clatterlabs.xyz/v1, with Authorization: Bearer clsk_... and X-Clatter-Account: CL-... on every call. Quick reference
• Every response has an X-Request-Id; log it so a request can be found later. Why log it
• Retry only 429 and 5xx errors, with backoff; honour Retry-After when it's sent. Which errors to retry

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