GPT 5.6 Sol

Supported Functionality

Description

GPT-5.6 Sol is the flagship model in OpenAI's GPT-5.6 family, released on July 9, 2026 for complex professional work, deep reasoning, and agentic tasks. In the API, the gpt-5.6 alias points to this model. Its knowledge cutoff is February 16, 2026; OpenAI has not disclosed its parameter count or a unified set of benchmark scores.

Compared with earlier GPT-5 models, it expands reasoning effort to six levels—none, low, medium, high, xhigh, and max—and adds persisted reasoning, Pro reasoning mode, Programmatic Tool Calling, explicit prompt caching, and multi-agent orchestration in beta. It can also process images at their original dimensions and use retrieval, code execution, computer interaction, MCP, and Skills through the Responses API.

Key Capabilities

• Configurable Deep Reasoning: Six reasoning-effort levels let developers balance depth, latency, and cost, while Pro mode targets complex tasks with higher quality requirements.
• Software Engineering and Coding: Hosted Shell, Apply Patch, Code Interpreter, and Skills support closed-loop code analysis, modification, execution, and verification.
• Agent and Tool Orchestration: Function calling, Programmatic Tool Calling, MCP, tool search, and multi-agent orchestration enable long-horizon automated workflows.
• Long-Context Processing: A 1,050,000-token context window can hold large codebases, document collections, and multi-turn task state, with up to 128,000 output tokens.
• Vision Understanding: Image input and original image detail support interfaces, charts, and document images where source-resolution information matters.
• Structured Generation: Native Structured Outputs can follow a supplied JSON Schema, supporting reliable integration with databases, workflows, and business APIs.
• Retrieval and Knowledge Synthesis: Web Search and File Search let the model incorporate public web information and private file content into its analysis.

Technical Strengths