Reasoning

Enable extended thinking and reasoning capabilities for agents using OpenAI, Anthropic, Google, and Vertex AI models.

Reasoning

RadarOS supports extended thinking (reasoning) across all major model providers. When enabled, the model produces an internal chain-of-thought before generating the final answer — improving performance on complex math, logic, and multi-step problems.

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Quick Start

import { Agent, google } from "@radaros/core";

const agent = new Agent({
  name: "Thinker",
  model: google("gemini-2.5-flash"),
  instructions: "Solve problems step by step.",
  reasoning: {
    enabled: true,
    budgetTokens: 8000,
  },
  logLevel: "info",
});

const result = await agent.run("What is the 15th prime number?");
console.log(result.text);

if (result.thinking) {
  console.log("Reasoning:", result.thinking);
}

console.log("Reasoning tokens:", result.usage.reasoningTokens);

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Configuration

reasoning.enabled · boolean · required

Enable or disable reasoning for this agent.

reasoning.effort · 'low' | 'medium' | 'high'

Reasoning effort level. OpenAI only — maps to reasoning_effort parameter. Default: "medium".

reasoning.budgetTokens · number

Maximum tokens allocated for the thinking phase. Anthropic, Google, Vertex AI — maps to budget_tokens / thinkingBudget. Default: 10000.

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Provider Support

Each provider maps ReasoningConfig to its native API:

Provider	API Parameter	Effort	Budget	Models
OpenAI	reasoning_effort	effort field	N/A	o1, o1-mini, o3-mini
Anthropic	thinking.budget_tokens	N/A	budgetTokens field	claude-sonnet-4-20250514
Google	thinkingConfig.thinkingBudget	N/A	budgetTokens field	gemini-2.5-flash, gemini-2.5-pro
Vertex AI	thinkingConfig.thinkingBudget	N/A	budgetTokens field	gemini-2.5-flash, gemini-2.5-pro

When reasoning is enabled for OpenAI, temperature is ignored (the API does not allow both). For Anthropic, the temperature parameter is removed when thinking is active.

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Output

When reasoning is enabled, RunOutput includes:

Field	Type	Description
thinking	string | undefined	The model’s internal chain-of-thought
usage.reasoningTokens	number | undefined	Tokens consumed by the reasoning phase

Streaming

During streaming, reasoning content is delivered as thinking chunks:

for await (const chunk of agent.stream("Solve this puzzle...")) {
  if (chunk.type === "thinking") {
    process.stdout.write(`[think] ${chunk.text}`);
  } else if (chunk.type === "text") {
    process.stdout.write(chunk.text);
  }
}

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ReasoningConfig Type

interface ReasoningConfig {
  enabled: boolean;
  effort?: "low" | "medium" | "high";
  budgetTokens?: number;
}

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Logging

When logLevel is "info" or higher, the agent logger displays:

• Thinking content (truncated, italic, dimmed)
• Reasoning token count with a brain icon in the usage summary