Anthropic AI Agent: Claude Sonnet 4 and Opus 4 with Think and Web Search tool

This workflow dynamically chooses between two new powerful Anthropic models — Claude Opus 4 and Claude Sonnet 4 — to handle user queries, based on their complexity and nature, maintaining scalability and context awareness with Anthropic web search function and Think tool.

Key Advantages

🔁 Dynamic Model Selection

Automatically routes each user query to either Claude Sonnet 4 (for routine tasks) or Claude Opus 4 (for complex reasoning), ensuring optimal performance and cost-efficiency.

🧠 AI Agent with Tool Use

The AI agent can utilize a web search tool to retrieve up-to-date information and a Think tool for complex reasoning processes — improving response quality.

📎 Memory Integration

Uses session-based memory to maintain conversational context, making interactions more coherent and human-like.

🧮 Built-in Calculation Tool

Handles numeric queries using an integrated calculator tool, reducing the need for external processing.

📤 Structured Output Parser

Ensures outputs are always well-structured and formatted in JSON, which improves consistency and downstream integrations.

🌐 Web Search Capability

Supports real-time information retrieval for current events, statistics, or details not available in the AI’s base knowledge.

Components Overview

Trigger**: Listens for new chat messages. Routing Agent**: Analyzes the message and returns the best model to use. AI Agent**: Handles the conversation, decides when to use tools. Tools**:

web_search for internet queries Think for reasoning Calculator for math tasks Models Used**:

claude-sonnet-4-20250514: Optimized for general and business logic tasks. claude-opus-4-20250514: Best for deep, strategic, and analytical queries.

How It Works Dynamic Model Selection
The workflow begins when a chat message is received. The Anthropic Routing Agent analyzes the user's query to determine the most suitable model (either Claude Sonnet 4 or Claude Opus 4) based on the query's complexity and requirements.
The routing agent uses predefined criteria to decide:
Claude Sonnet 4: Best for standard tasks like real-time workflow routing, data validation, and routine business logic.
Claude Opus 4: Reserved for complex scenarios requiring deep reasoning, advanced analysis, or high-impact decisions.

Query Processing and Response Generation
The selected model processes the query, leveraging tools like web_search for real-time information retrieval, Think for internal reasoning, and Calculator for numerical tasks.
The AI Agent coordinates these tools, ensuring the response is accurate and context-aware. A Simple Memory node retains session context for coherent multi-turn conversations.
The final response is formatted and returned to the user without intermediate steps or metadata.

Set Up Steps Node Configuration
Trigger: Configure the "When chat message received" node to handle incoming user queries.
Routing Agent: Set up the "Anthropic Routing Agent" with the system message defining model selection logic. Ensure it outputs a JSON object with prompt and model fields.
AI Model Nodes: Link the "Sonnet 4 or Opus 4" node to dynamically use the selected model. The "Sonnet 3.7" node powers the routing agent itself.

Tool Integration
Attach the "web_search" HTTP tool to enable internet searches, ensuring the API endpoint and headers (e.g., anthropic-version) are correctly configured.
Connect auxiliary tools (Think, Calculator) to the "AI Agent" for extended functionality.
Add the "Simple Memory" node to maintain conversation history.

Credentials
Provide an Anthropic API key to all nodes requiring authentication (e.g., model nodes, web search).

Testing
Activate the workflow and test with sample queries to verify:
Correct model selection (e.g., Sonnet for simple queries, Opus for complex ones).
Proper tool usage (e.g., web searches trigger when needed).
Memory retention across chat turns.

Deployment
Once validated, set the workflow to active for live interactions.

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