# llm CLI plugin llm-anthropic 0.29 adds support for Claude Opus 5.5

> Simon Willison reports llm-anthropic 0.29 adds support for Claude Opus 5.5, runnable as llm -m claude-opus-5.5.

- **Topic**: Models
- **Published**: 2026-09-23T16:27:36.167Z
- **Canonical URL**: https://highsignal.sh/stories/llm-cli-plugin-llm-anthropic-0-29-adds-support-for-claude-opus-5-5-7ac2f1b3

## Why It Matters

The release concerns the llm command-line tool's Anthropic plugin, not an Anthropic launch; the post gives no model details, pricing, or benchmarks, so it only establishes that the plugin accepts the claude-opus-5.5 name.

## Key Findings & Analysis

### Plugin update

llm-anthropic 0.29 adds support for Claude Opus 5.5, per Simon Willison's release post.

### What's new

The release shows usage as llm -m claude-opus-5.5 with a prompt.

### Context

The post is tagged llm and anthropic; no pricing, availability, or benchmarks are provided.

## Original Evidence & Verbatim Citations

> "llm-anthropic 0.29 Adds support for Claude Opus 5.5: llm -m claude-opus-5.5"

— *Grounded field: headline*

> "Release: llm-anthropic 0.29"

— *Grounded field: headline*

> "llm-anthropic 0.29 Adds support for Claude Opus 5.5: llm -m claude-opus-5.5"

— *Grounded field: summary*

> "Adds support for Claude Opus 5.5"

— *Grounded field: whyItMatters*

> "Release: llm-anthropic 0.29"

— *Grounded field: whyItMatters*

> "Release: llm-anthropic 0.29 Adds support for Claude Opus 5.5"

— *Grounded field: section:0*

> "llm -m claude-opus-5.5"

— *Grounded field: section:1*

> "Tags: llm, anthropic"

— *Grounded field: section:2*

## Primary Sources & Citations

- [llm-anthropic 0.29](https://simonwillison.net/2026/Sep/22/llm-anthropic/) — *Simon Willison* (Reporting)

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