Workers AI sometimes streams a numeric-looking token as a JSON number instead of a string, e.g. {"choices":[{"delta":{"content":0.005}}]}. createAI drops it silently, so $0.005 comes out as $ and [1] as [].

const ai = createAI({ binding: env.AI });
const { text } = streamText({ model: ai("@cf/meta/llama-3.3-70b-instruct-fp8-fast"), prompt });
// stream chunks: "Costs $", 0.005, " each"  ->  text is "Costs $ each"

normalizeDelta in packages/agents/src/models/core/chat-completions/stream.ts passes a numeric content through unchanged, and the wires then read it with typeof === "string" (text() in ai-sdk/wires/shared.ts, pushText in pi-ai/wires/chat-completions.ts). Numeric reasoning / reasoning_content and a numeric native response are dropped the same way. Coercing numbers to strings in the normalizer fixes all of them; the non-streaming path already does this (contentText in response.ts).

Confirmed with a fake-binding test on main.

From cloudflare/ai#655.