@mast-ai/openai

OpenAI LlmAdapters for MAST. Calls OpenAI directly from the browser, bypassing the URP backend entirely.

Two adapters ship side by side:

• OpenAIChatCompletionsAdapter wraps the Chat Completions API. Broad model coverage, works against OpenAI-compatible providers (OpenRouter, DeepSeek). Reasoning content from compatible providers is forwarded as thinking events; OpenAI itself does not expose reasoning content via this endpoint.
• OpenAIResponsesAdapter wraps the Responses API. Required to surface reasoning summaries from gpt-5 and o-series models as thinking events.

Both support tool calling, streaming, and structured output.

Install

npm install @mast-ai/core @mast-ai/openai

Chat Completions usage

import { AgentRunner, ToolRegistry, createAgent } from '@mast-ai/core';
import { OpenAIChatCompletionsAdapter } from '@mast-ai/openai';

const adapter = new OpenAIChatCompletionsAdapter(
  import.meta.env.VITE_OPENAI_API_KEY,
  'gpt-4o-mini',
);

const registry = new ToolRegistry();
// ...register tools...

const agent = createAgent({ name: 'Assistant', instructions: '...', tools: [] });
const runner = new AgentRunner(adapter, registry);

const result = await runner.run(agent, 'Hello!');

Responses API usage (with reasoning)

import { OpenAIResponsesAdapter } from '@mast-ai/openai';

const adapter = new OpenAIResponsesAdapter(apiKey, 'gpt-5', undefined, {
  reasoningEffort: 'medium',
  // reasoningSummary defaults to "auto"; set to false to disable thinking events.
});

OpenAIResponsesAdapter runs statelessly (store: false) — the runner's Conversation history is replayed on every request. With reasoningSummary set, every reasoning model call emits thinking events alongside the final text.

Note: Calling OpenAI directly from the browser exposes your API key. Use this in trusted contexts (extensions, internal tools, demos) or front it with a proxy that injects the key server-side. Both adapters set dangerouslyAllowBrowser: true to permit browser usage of the official OpenAI SDK.

License

Apache-2.0. Copyright 2026 Andre Cipriani Bandarra.