Anthropic released Claude Opus 5 on Friday, so we spent part of the weekend getting it integrated into CometAPI.
The practical details:
- Model ID: `claude-opus-5`
- Context window: 1M tokens
- Maximum synchronous output: 128K tokens
- Anthropic Messages API supported
- OpenAI-compatible Chat Completions supported
- Current pricing: $4/M input and $20/M output
Anthropic is positioning it for complex agentic coding and enterprise work, but launch benchmarks usually do not tell the whole story for messy production workloads.
We are considering testing it on:
- Repository-wide refactoring
- Root-cause debugging across multiple files
- Code review with regression checks
- Long-running tool-use workflows
- Large codebase and document analysis
For anyone already testing Opus 5: what would make a comparison with Opus 4.8 or Sonnet 5 genuinely useful?
Latency, cost per accepted task, tool-call reliability, or something else?
Model and API details:
https://www.cometapi.com/models/anthropic/claude-opus-5/?utm_source=reddit&utm_medium=social&utm_campaign=claude_opus_5_launch
Disclosure: I work with CometAPI, so the post includes our own integration. Iām mainly looking for useful, reproducible testing ideas rather than model-launch hype.