Claude Opus 4.1 API for agentic coding and reasoning

Claude Opus 4.1 is Anthropic’s upgraded Opus 4 model for agentic tasks, real-world coding, and reasoning. Anthropic reports 74.5% on SWE-bench Verified and highlights improved in-depth research and data analysis, especially for detail tracking and agentic search. For teams choosing a flagship Claude model, Opus 4.1 is positioned as the recommended upgrade from Opus 4. The Claude Opus 4.1 API gives teams a reliable option when quality and planning depth are required. Opus 4.1 is often chosen for complex planning and long tasks.

Anthropic reports state-of-the-art coding performance at 74.5% on SWE-bench Verified. GitHub notes Opus 4.1 improves across most capabilities relative to Opus 4, with particularly notable gains in multi-file refactoring. Rakuten Group also highlights that Opus 4.1 can pinpoint exact corrections in large codebases without unnecessary edits. Together, these signals point to higher reliability for refactors, bug fixes, and code modernization work. The Claude Opus 4.1 API is built for these demands. Opus 4.1 helps teams validate refactor plans before release.

Anthropic says Opus 4.1 improves in-depth research and data analysis skills, especially detail tracking and agentic search. That makes it useful for summarizing long specs, incident timelines, policy documents, and complex tickets where accuracy depends on keeping many details aligned. Teams often use Opus 4.1 to produce structured reports, risk summaries, and evidence-backed narratives when a consistent long-range view matters for decisions. The Claude Opus 4.1 API supports these analysis workflows at scale. Claude Opus 4.1 API supports long-form evidence tracking and consistent summaries.

Yes. Anthropic explicitly recommends upgrading from Opus 4 to Opus 4.1 for all uses and notes that pricing remains the same as Opus 4. The announcement positions Opus 4.1 as the best choice for agentic tasks, real-world coding, and reasoning improvements. If you are already using Opus 4, moving to Opus 4.1 is intended to be a low-friction upgrade that delivers measurable gains without changing your pricing tier. Claude Opus 4.1 API users can keep prompts and measure improvements.

EvoLink documents a specific model ID list for Claude. For Opus 4.1, use `claude-opus-4-1-20250805`, which appears in the available options list. Use the exact ID shown in the EvoLink docs to avoid routing errors and keep behavior stable across environments. Keep the model ID in a shared config file, log it in requests for audits, and avoid hard-coding it in multiple places so upgrades remain controlled. The Claude Opus 4.1 API should always reference this ID. Pin the Claude Opus 4.1 API ID in deployment configs.

EvoLink requires Bearer token authentication. Create an API key in the EvoLink dashboard, then call POST https://api.evolink.ai/v1/messages with Authorization: Bearer <token> and Content-Type: application/json. This is the single endpoint documented for Claude on EvoLink. Keep keys server-side, rotate them regularly, and separate staging and production keys for auditability and access control in production systems. Use the same endpoint for Claude Opus 4.1 API traffic across environments. Use the same endpoint for all Claude Opus 4.1 API environments.

EvoLink lists three required fields: model, max_tokens, and messages. The model must be one of the documented options, max_tokens must be an integer greater than or equal to 1, and messages is the structured input array. The API may stop before reaching the maximum, so size max_tokens for your longest acceptable response. Keep a shared request schema to reduce integration errors and ensure consistent behavior. Claude Opus 4.1 API requests should follow the same required fields.

Yes. EvoLink documents a stream boolean that enables server-sent events for incremental output. It also lists optional controls such as system, temperature, top_p, top_k, stop_sequences, tool_choice, tools, thinking, and metadata. Start with defaults, then adjust one parameter at a time while evaluating real prompts. Keep a configuration baseline per environment so changes are traceable and you can roll back if outputs shift. Claude Opus 4.1 API tuning should follow the same guidance. Claude Opus 4.1 API teams should document defaults and changes.