chore: use latest chat model names

[mdrxy]

• use latest chat model in examples to highlight support
• drop prefixed openai: and anthropic: where possible due to dynamic routing
• standardize on full model name instead of aliases (for easier future updates)

[github-actions]

Mintlify preview ID generated: preview-mdrxyc-1761848926-2edc25a

[Copilot]

Pull Request Overview

This PR updates model identifiers across the LangChain documentation to:

1. Remove provider prefixes from model identifiers (e.g., openai:gpt-4o → gpt-4o, anthropic:claude-sonnet-4-5 → claude-sonnet-4-5-20250929)
2. Update Anthropic model versions to newer dated versions (e.g., claude-3-5-haiku-latest → claude-haiku-4-5-20251001, claude-sonnet-4-5 → claude-sonnet-4-5-20250929)
3. Update some OpenAI model references (e.g., chatgpt-4o-latest → gpt-4o)

Key Changes:

• Model identifier format standardization removing provider prefixes for OpenAI and Anthropic models
• Anthropic model version updates to specific dated releases
• Consistent application across Python and JavaScript documentation

Reviewed Changes

Copilot reviewed 78 out of 78 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/snippets/trace-with-anthropic.mdx	Updated Anthropic model to claude-sonnet-4-5-20250929
src/snippets/oss/ui-js.mdx	Removed parentheses from function reference in link
src/snippets/oss/studio.mdx	Removed openai: prefix from model identifier
src/snippets/chat-model-tabs*.mdx	Updated model identifiers to remove prefixes and use dated versions
src/oss/python/**/*.mdx	Consistent model identifier updates across Python docs
src/oss/javascript/**/*.mdx	Consistent model identifier updates across JavaScript docs
src/oss/langgraph/**/*.mdx	Updated model identifiers in LangGraph examples
src/oss/langchain/**/*.mdx	Updated model identifiers in LangChain core docs
src/oss/deepagents/**/*.mdx	Updated model identifiers in DeepAgents docs
src/langsmith/**/*.mdx	Updated model identifiers in LangSmith docs

Comments suppressed due to low confidence (3)

src/oss/deepagents/subagents.mdx:233

• Inconsistent model identifier format. This line still uses the provider prefix openai:gpt-4o while the rest of the PR removes provider prefixes. For consistency with the PR's changes, this should be changed to gpt-4o.

        "model": "openai:gpt-4o",  # Better for numerical analysis

src/oss/deepagents/subagents.mdx:80

• Inconsistent model identifier format. This line still uses the provider prefix openai:gpt-4o while the rest of the PR removes provider prefixes. For consistency with the PR's changes, this should be changed to gpt-4o.

    "model": "openai:gpt-4o",  # Optional override, defaults to main agent model

src/oss/deepagents/subagents.mdx:38

• Documentation inconsistency. The documentation still describes and exemplifies the old provider prefix format (\"provider:model-name\" and \"openai:gpt-4o\"), but the PR removes this format throughout the codebase. This documentation should be updated to reflect the new format without provider prefixes (e.g., \"gpt-4o\").

- **model** (`str | BaseChatModel`): Override the main agent's model. Use the format `"provider:model-name"` (for example, `"openai:gpt-4o"`).