Best Foundation Models for OpenCode Go

Kimi K3.1 Pro is an advanced multimodal AI reasoning model developed by Moonshot AI for software engineering, autonomous agents, technical design, and analytical knowledge work. Built on the Kimi K3 architecture, the model uses approximately 2.8 trillion total parameters with 104 billion active parameters and supports a one-million-token context window. Its enhanced reasoning capabilities enable complex, multistep problem-solving across programming, scientific analysis, financial research, and business operations. Coding features include source code generation, debugging, repository-level modifications, automated testing, and end-to-end application development. The model can create interactive websites, Three.js environments, games, and software projects using development frameworks and engines such as Unity, Unreal Engine, and Godot. Its spatial reasoning capabilities support CAD code generation, parametric modeling, 3D asset creation, and geometry adjustments through tools such as Blender. Financial analysis capabilities include spreadsheet modeling, document-based research, numerical reasoning, and investment analysis using information from multiple sources. Kimi K3.1 Pro supports text and image inputs, external tool use, and long-running agentic workflows that require planning and iterative execution. The model is accessible through Kimi applications and APIs, with an additional Highspeed version designed to deliver approximately two to three times faster responses.

Kimi K3 is a large-scale AI model from Moonshot AI designed for advanced reasoning, software engineering, visual understanding, agentic workflows, and knowledge work. The model is built with 2.8 trillion parameters and uses Kimi Delta Attention, a hybrid linear attention design created to support long-context intelligence. It also includes Attention Residuals and a native 1 million token context window, giving developers room to work with large files, repositories, documentation sets, transcripts, and enterprise knowledge bases. Kimi K3 always runs with thinking mode enabled and currently supports maximum reasoning effort by default. Developers can access the model through Moonshot’s OpenAI-compatible API using Python, cURL, and the OpenAI SDK. The API supports standard chat completions, streaming output, structured JSON Schema responses, partial continuation from a prefix, custom tool calling, required tool choice, and dynamic tool loading. Kimi K3 also supports vision inputs, including local images encoded as base64 and video files uploaded through the file API. Automatic context caching helps repeated long-prefix workflows become more efficient without requiring manual cache IDs or extra cache parameters. By combining long context, visual understanding, tool use, structured output, and advanced reasoning, Kimi K3 is built for developers creating sophisticated AI agents, coding systems, research tools, and enterprise applications.

GLM-5.3 is Z.ai’s advanced coding and agentic reasoning model built through scaled post-training on top of the GLM-5.2 base model. The release focuses on frontier coding, long-horizon software engineering, agent tasks, cyber evaluation, and reinforcement learning at scale. GLM-5.3 improves significantly over GLM-5.2 on complex coding benchmarks, real-world engineering environments, Terminal Bench 3.0, DeepSWE, Agents’ Last Exam, and Z.ai’s internal Code Bench. The model is trained on environments that resemble real professional work, including tasks involving codebases, infrastructure, documentation, compute clusters, experiments, bottleneck diagnosis, implementation, testing, and measurable optimization. Z.ai’s post-training stack includes IndexShare for efficient long-context processing, SAO for reinforcement learning on long-horizon tasks, and slime for large-scale asynchronous training. GLM-5.3 supports three thinking effort levels, including low, high, and max, with max recommended for coding tasks. The model also demonstrates emergent cyber capabilities across vulnerability discovery and exploitation benchmarks, prompting continued safety evaluation and hardening before weights are released. GLM-5.3 can be used through the GLM Coding Plan, ZCode, Claude Code, OpenCode, and other coding agent workflows. By combining stronger coding performance, long-horizon task execution, post-training scale, cyber evaluation, reasoning effort controls, and coding-agent integrations, GLM-5.3 supports advanced developer and research workflows.

MiniMax M3 is a frontier open-weight AI model built for coding, agentic work, multimodal understanding, and ultra-long-context tasks. The model supports up to a 1 million token context window, allowing it to work across large codebases, long documents, logs, project histories, and complex task environments. MiniMax M3 introduces MiniMax Sparse Attention, a sparse attention architecture designed to make long-context processing more efficient. The model is natively multimodal, with training that supports deeper semantic fusion across text, image, and video inputs. It is designed to support software engineering tasks, repository analysis, terminal-style work, browser-style retrieval, tool use, and autonomous workflows. MiniMax M3 has a mixture-of-experts architecture with hundreds of billions of total parameters and a smaller activated parameter count for more efficient inference. Developers can use it for AI coding assistants, workflow automation, research agents, document analysis, visual reasoning, and enterprise AI systems. Its long-context capability makes it especially useful when tasks require many files, references, instructions, or interaction histories to stay available at once. MiniMax M3 helps teams build more capable AI agents that can understand larger problems, work across multiple modalities, and execute complex tasks with stronger context awareness.

Claude is an advanced AI assistant created by Anthropic to help users think, create, and work more efficiently. It is built to handle tasks such as content creation, document editing, coding, data analysis, and research with a strong focus on safety and accuracy. Claude enables users to collaborate with AI in real time, making it easy to draft websites, generate code, and refine ideas through conversation. The platform supports uploads of text, images, and files, allowing users to analyze and visualize information directly within chat. Claude includes powerful tools like Artifacts, which help organize and iterate on creative and technical projects. Users can access Claude on the web as well as on mobile devices for seamless productivity. Built-in web search allows Claude to surface relevant information when needed. Different plans offer varying levels of usage, model access, and advanced research features. Claude is designed to support both individual users and teams at scale. Anthropic’s commitment to responsible AI ensures Claude is secure, reliable, and aligned with real-world needs.

Gemini is Google’s intelligent AI platform built to support productivity, creativity, and learning across work, school, and everyday life. It allows users to ask questions, generate text, images, and videos, and explore ideas using conversational AI powered by Gemini 3. By integrating directly with Google Search, Gemini provides grounded answers and supports detailed follow-up discussions on complex topics. The platform includes advanced tools like Deep Research, which condenses hours of online research into structured reports in minutes. Gemini also enables real-time collaboration and spoken brainstorming through Gemini Live. Users can connect Gemini to Gmail, Google Docs, Calendar, Maps, and other Google services to complete tasks across multiple apps at once. Custom AI experts called Gems allow users to save instructions and tailor Gemini for specific roles or workflows. Gemini supports large file analysis with a long context window, making it capable of reviewing books, reports, and large codebases. Flexible subscription tiers offer different levels of access to models, credits, and creative tools. Gemini is available on web and mobile, making it accessible wherever users need intelligent assistance.

Qwen is a next-generation AI system that brings advanced intelligence to users and developers alike, offering free access to a versatile suite of tools. Its capabilities include Qwen VLo for image generation, Deep Research for multi-step online investigation, and Web Dev for generating full websites from natural language prompts. The “Thinking” engine enhances Qwen’s reasoning and logical clarity, helping it tackle complex technical, analytical, and academic challenges. Qwen’s intelligent Search mode retrieves web information with precision, using contextual understanding and smart filtering. Its multimodal processing allows it to interpret content across text, images, audio, and video, enabling more accurate and comprehensive responses. Qwen Chat makes these features accessible to everyone, while developers can tap into the Qwen API to build apps, integrate Qwen into workflows, or create entirely new AI-driven experiences. The API follows an OpenAI-compatible format, making migration and adoption seamless. With broad platform support—web, Windows, macOS, iOS, and Android—Qwen delivers a unified, powerful AI ecosystem for all kinds of users.

MiniMax M3.1 Flash is an advanced hosted language model designed specifically for developers who are creating coding assistants, AI agents, and various software applications. It can be accessed via MiniMax's API and MiniMax Code, allowing it to process inputs in text, image, and video formats while generating relevant text responses. Among its documented applications are functionalities such as code generation, debugging, complex reasoning tasks, tool utilization, analysis of codebases and documents, as well as enhancing computer workflows. The API boasts an impressive context window that can handle up to 1 million tokens, offers adjustable reasoning capabilities, and supports request formats that are compatible with both OpenAI and Anthropic standards. Charges for usage are based on the number of tokens used for input, output, and cached input. Comprehensive documentation is provided by MiniMax to assist with API integration and effective model utilization. M3.1 Flash is accessible through the hosted API, M Plan, and MiniMax Code, while there are plans to release model weights in the future, expanding its potential applications even further. This innovation represents a significant step forward in the integration of AI into software development processes.