ModelRefs / Claude Opus 4 - AI model implementation reference

Claude Opus 4 - AI model implementation reference

Claude Opus 4 is Anthropic's May 22, 2025 hybrid-reasoning model for complex coding, reasoning, multimodal analysis, and long-running agent workflows. The immutable claude-opus-4-20250514 snapshot is now retired on Anthropic-operated platforms, so this page serves as a historical implementation, evaluation, and migration reference rather than a recommendation for new deployment.

Overview

This historical profile provides provisional decision support from source-scoped evidence; it is not a final ranking or production guarantee.

Claude Opus 4 is Anthropic's May 22, 2025 hybrid-reasoning model for complex coding, graduate-level reasoning, multimodal analysis, and long-running agent workflows. This reference maps evidence to the immutable claude-opus-4-20250514 snapshot rather than transferring results from Claude Opus 4.1, later Opus releases, mutable aliases, or high-compute selection variants.

The evidence ledger includes Anthropic-published SWE-bench Verified, Terminal-Bench, GPQA Diamond, AIME 2025, tau-bench Retail, tau-bench Airline, and MMMU results, with the associated thinking, agent-harness, sampling, and step-limit qualifications retained. Anthropic publishes the source and model snapshot but not exact evaluation execution dates, so ModelRefs leaves those dates undisclosed instead of treating the May 22 publication date as a benchmark run date.

Anthropic retired claude-opus-4-20250514 on its operated platforms on June 15, 2026 and recommends Claude Opus 4.8 for migration. The page therefore serves as a historical implementation, comparison, evaluation, and migration reference; partner-cloud availability follows each partner's own lifecycle, while exact training corpus, architecture, parameter count, training compute, and independent reproduction evidence remain unavailable.

Benchmark & Evaluation

ModelRefs currently has partial, narrow benchmark coverage for Claude Opus 4. Treat the available benchmark evidence as one input to the decision, not a guarantee that Claude Opus 4 is the strongest option for your workload, and evaluate it on representative workloads before selecting it.

  • Seven canonical provider-run records cover SWE-bench Verified, Terminal-Bench, GPQA Diamond, AIME 2025, tau-bench Retail, tau-bench Airline, and MMMU validation for the dated Claude Opus 4 launch snapshot.
  • These scores are source-scoped and provider-reported. Several use extended thinking, tool scaffolds, increased step limits, or Anthropic-specific agent frameworks; none supplies a physical execution date or independent reproduction.

Implementation considerations

  • Treat claude-opus-4-20250514 as a retired, immutable evaluation subject; inventory and migrate production calls rather than routing new traffic to it.
  • For historical reproduction, preserve the exact extended-thinking budget, tool scaffold, prompt, sampling settings, and cloud channel because the launch scores are model-plus-harness results.
  • Anthropic retired claude-opus-4-20250514 on its operated platforms on June 15, 2026; requests to a retired model fail, and Anthropic recommends claude-opus-4-8 as the replacement.
  • Amazon Bedrock and Google Cloud control their own lifecycle schedules. Verify the exact partner model ID, region, retirement state, and data terms before assuming historical availability.

Architecture disclosure

  • Anthropic documents Claude Opus 4 as a proprietary hosted hybrid-reasoning model with text and image input, text output, a 200,000-token context window, manual extended thinking, and tool use. It does not publish parameter count, layer design, tokenizer specification, serving topology, or model weights.
  • Launch evaluations distinguish standard single-attempt results from parallel high-compute selection. ModelRefs admits only explicitly scoped rows and does not collapse the high-compute result into the standard score.

Prompts and code examples

Historical pinned Messages API request (retired snapshot)

import Anthropic from "@anthropic-ai/sdk";

const client = new Anthropic();
// Historical reproduction only: Anthropic retired this snapshot on 2026-06-15.
const message = await client.messages.create({
  model: "claude-opus-4-20250514",
  max_tokens: 4096,
  messages: [{
    role: "user",
    content: "Review this migration plan and identify the three highest-risk assumptions.",
  }],
});

console.log(message.content);

Provider implementation source

Training disclosure

  • Anthropic does not publish a complete Claude Opus 4 training-data inventory, parameter count, training-compute ledger, or reproducible training recipe.
  • Anthropic's privacy documentation describes broad categories of model-training data and personal-data handling, but it does not identify the exact Claude Opus 4 corpus or provide a model-specific contamination audit.
  • The reviewed launch, system-card, and retirement sources do not establish an exact training cutoff suitable for ModelRefs to present as a verified model-specific fact.

History and source-reviewed changelog

  1. 2025-05-22 — Claude Opus 4 launched

    Anthropic released Claude Opus 4 and Claude Sonnet 4 with hybrid reasoning, extended thinking with tool use, and provider-run coding, reasoning, agentic, multilingual, and vision evaluations.

    Milestone source
  2. 2026-04-14 — Claude Opus 4 deprecated

    Anthropic announced the retirement schedule for claude-opus-4-20250514 and directed developers to migrate to Claude Opus 4.8.

    Milestone source
  3. 2026-06-15 — Claude Opus 4 retired on Anthropic-operated platforms

    Anthropic marks the dated Claude Opus 4 API model as retired; historical evidence remains valid only for the pinned snapshot and does not establish current availability.

    Milestone source

Risks and limitations

  • Outputs can be incorrect or unsuitable for the intended task; use task-specific evaluation, grounding, and human review where consequences are material.
  • API availability, model aliases, rate limits, data controls, regions, and prices are mutable and differ by product channel.

Source coverage

ModelRefs verified the Claude Opus 4 launch, exact API snapshot identity, system card, historical pricing, Messages API shape, extended-thinking controls, retirement record, and seven source-scoped provider evaluations. Anthropic does not publish the physical evaluation execution dates, so ModelRefs preserves them as undisclosed rather than substituting the May 22, 2025 publication date.

Sources

Continue your research

Use these connected ModelRefs sections to compare alternatives, inspect implementation paths, and review the evidence and governance boundaries relevant to Claude Opus 4 - AI model implementation reference.