[Kinfe123]

Problem

With streamfold 0.1.14 and openai 7.45.1, passing the result of client.responses.create({ model, input, stream: true }) directly to readStructured(events, { integration: openAI }) fails TypeScript compilation. Feeding SDK events into push or pushAll fails too, even though the adapter can ignore non-tool events at runtime.

Root cause

The fallback event type requires a string index signature. The SDK declares its events as interfaces without that signature, so events such as audio deltas cannot satisfy the adapter's union.

Change

Add a minimal discriminator-only fallback to the existing union. Keep the existing branches so raw event literals with extra provider fields remain accepted. There is no runtime or parser change and no SDK runtime dependency.

Verification

• Added a compile-time consumer fixture using the real OpenAI SDK response stream, both manual push methods, and an unknown event literal.
• pnpm typecheck fails before the declaration change with TS2322/TS2345 at the real SDK boundaries and passes afterward.
• pnpm release:check passes: 197 JavaScript tests, 11 Rust tests, type/syntax checks, WASM build, formatting, Clippy, and package checks.
• This is separate from fix(openai): preserve final arguments and suppress duplicate completions #94, which fixes runtime completion behavior and does not change these declarations.

Public surface

Widens OpenAiResponsesToolEvent without removing any existing shape. Updates API documentation and the unreleased changelog. OpenAI is a development-only dependency for the consumer type check.

[Kinfe123]

lgtm, real openai sdk streams now typecheck without casts.