Claude Opus 4.5
Anthropic's frontier coding and reasoning model with vision, tool use, and a 198K context window.
Overview
What is Claude Opus 4.5
Claude Opus 4.5 is Anthropic's frontier LLM released in November 2025, optimized for complex coding, agentic workflows, and reasoning. It supports vision, tool use, and web search, and offers a 198K context window with up to 32K tokens of output.
Running it privately on Venice
On Venice, Claude Opus 4.5 runs under an anonymized privacy tier — your prompts are not stored, profiled, or used for training. You get the full frontier model with vision, reasoning, tool use, and web search, but with zero retention and no Big-Tech surveillance.
Assessment
Strengths and limitations
- State-of-the-art performance on real-world software engineering, coding, and agentic tasks, including cross-system debugging.
- Supports vision, function calling, reasoning, web search, structured JSON output, and multiple image inputs for complex multimodal workflows.
- Handles ambiguous instructions and tradeoff reasoning without heavy hand-holding.
- 198K context window and 32K max output for deep document analysis and long-form generation.
- Available on Venice with zero retention: your prompts are not stored or profiled.
- Closed proprietary weights: cannot be self-hosted or fine-tuned.
- Premium per-token pricing compared to open-weight alternatives.
- 198K context is smaller than newer rivals such as Opus 4.8 or Grok 4.5.
- Not uncensored; subject to Anthropic's safety alignment and Constitutional AI guardrails.
- Generally slower and more expensive than mid-tier models like Sonnet 4.6.
Capabilities
What it supports
- Tool use / function calling
- Vision (image input)
- Reasoning
- Web search
- Code-optimized
- Structured output (JSON schema)
- Audio input
- Video input
- Multiple image inputs
- Log probabilities
Specifications
Datasheet
- Maker
- Anthropic
- Released
- November 24, 2025
- Architecture
- Transformer-based (full details undisclosed)
- Parameters
- Undisclosed
- Open weights
- No — proprietary
- Context window
- 198K tokens
- Max output
- 32.768K tokens
- Capabilities
- Vision, Function calling, Reasoning, Web search, Code-optimized
- Privacy on Venice
- Anonymized — prompts not stored
- Available on Venice since
- Dec 2025
API
Call it from your code
Venice exposes an OpenAI-compatible API. Point your base URL at Venice and pass the model id.
curl https://api.venice.ai/api/v1/chat/completions \
-H "Authorization: Bearer $VENICE_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "claude-opus-4-5",
"messages": [{ "role": "user", "content": "Explain quantum tunneling simply." }]
}'Pricing
What it costs on Venice
Billed per token on Venice: $6 per 1M input tokens and $30 per 1M output tokens.
New Venice accounts include a free daily allowance and 500 welcome credits — no credit card required.
Alternatives
How it compares
| Model | Context window | Strongest at | Open weights | Price (Venice) |
|---|---|---|---|---|
| Claude Opus 4.5 | 198K tokens | Coding, agents & reasoning | No | $6 in · $30 out / 1M |
| Claude Opus 4.8 | 1M tokens | Long-horizon agentic coding | No | $6 in · $30 out / 1M |
| Claude Sonnet 4.6 | 1M tokens | Speed & value | No | $3.60 in · $18 out / 1M |
| DeepSeek V3.2 | 160K tokens | Open-weight coding | Yes | $0.33 in · $0.48 out / 1M |
Frontier reasoning and coding with full vision and tool support.
Use cases
What it is good for
- 01Complex software engineering: multi-file refactoring, subtle bug hunting, and architectural decisions.
- 02Agentic workflows: long-running tasks that combine tool use, web search, and reasoning.
- 03Multimodal analysis: interpreting diagrams, spreadsheets, and UI mockups via vision input.
- 04Research synthesis: deep analysis of long documents with structured JSON extraction.
- 05Enterprise automation: reliable instruction following for sensitive business processes.
Prompting
Getting better results
Be explicit about multi-step goals; Opus 4.5 excels at planning and executing complex agentic sequences.
Combine vision and code prompts — e.g., paste a screenshot of an error and ask for the fix.
Use structured output (JSON schema) when you need machine-readable results from messy inputs.
For long contexts, repeat critical instructions at the beginning and end of the prompt.
Version history
Drop-in predecessor improving precision for coding and agentic tasks.
Current on Venice — state-of-the-art coding, reasoning, and vision.
Successor with 1M context and hybrid reasoning for long-running agents.
FAQ
Frequently asked questions
Claude Opus 4.5 is Anthropic's frontier large language model released in November 2025. It is designed for complex coding, agentic workflows, and reasoning, and supports vision, tool use, web search, and structured output.
Venice bills per token at $6 per 1M input tokens and $30 per 1M output tokens, with cached input priced at $0.60 per 1M tokens. You pay only for what you use with no subscription required.
It is neither free nor open source. The weights are proprietary and closed, so you cannot self-host or fine-tune the model. Access is available through Venice's API or app on a pay-per-use basis.
Yes. On Venice, the model supports function calling, reasoning, web search, vision input, multiple image inputs, and structured JSON output — making it suitable for complex agentic workflows.
Choose Opus 4.5 for the highest reasoning and coding quality on difficult tasks. Choose Sonnet 4.6 for a 1M context window and lower per-token cost when speed and volume matter more than absolute peak capability.
Opus 4.5 leads on agentic coding, reasoning, and multimodal tasks but is proprietary and more expensive. DeepSeek V3.2 is fully open-weight and far cheaper, making it ideal for teams that need model sovereignty or self-hosting.
It runs under Venice's anonymized privacy tier. Your prompts are not stored, profiled, or used for training, giving you zero-retention access to a frontier model without Big-Tech surveillance.
The model supports up to 198,000 tokens of context and can generate up to 32,768 tokens in a single response.
Run Claude Opus 4.5 privately
No prompt logging. No data used for training.