[DOCS] Deprecated environment variable `ANTHROPIC_SMALL_FAST_MODEL` still used in 3P provider documentation

Documentation Type

Unclear/confusing documentation

Documentation Location

• https://code.claude.com/docs/en/amazon-bedrock - https://code.claude.com/docs/en/google-vertex-ai

Section/Topic

• Amazon Bedrock: Section 3. Configure Claude Code and Section 4. Model configuration - Google Vertex AI: Section 4. Configure Claude Code and Section 5. Model configuration

Current Documentation

In amazon-bedrock.md:

``bash # Optional: Override the region for the small/fast model (Haiku) export ANTHROPIC_SMALL_FAST_MODEL_AWS_REGION=us-west-2 ` ... `bash # Using inference profile ID export ANTHROPIC_MODEL='global.anthropic.claude-sonnet-4-5-20250929-v1:0' export ANTHROPIC_SMALL_FAST_MODEL='us.anthropic.claude-haiku-4-5-20251001-v1:0' ``

In google-vertex-ai.md:

``bash export ANTHROPIC_MODEL='claude-opus-4-1@20250805' export ANTHROPIC_SMALL_FAST_MODEL='claude-haiku-4-5@20251001' ``

What's Wrong or Missing?

The documentation for 3rd-party providers is suffering from "deprecation drift." According to the CHANGELOG.md (and confirmed in the model-config.md reference), the environment variable ANTHROPIC_SMALL_FAST_MODEL has been deprecated in favor of ANTHROPIC_DEFAULT_HAIKU_MODEL as of version 2.1.2.

Continuing to instruct users to set the deprecated variable in the setup guides for Bedrock and Vertex AI is confusing for new users and may lead to configuration issues in future versions where the legacy variable name might be removed.

Suggested Improvement

Update all setup examples to use the current standard variable names.

For amazon-bedrock.md:
Update the code blocks to:

# Optional: Override the region for the default Haiku model
export ANTHROPIC_DEFAULT_HAIKU_MODEL_AWS_REGION=us-west-2
...
export ANTHROPIC_DEFAULT_HAIKU_MODEL='us.anthropic.claude-haiku-4-5-20251001-v1:0'

For google-vertex-ai.md:
Update the code blocks to:

export ANTHROPIC_MODEL='claude-opus-4-1@20250805'
export ANTHROPIC_DEFAULT_HAIKU_MODEL='claude-haiku-4-5@20251001'

Impact

High - Prevents users from using a feature

Additional Context

• Evidence from CHANGELOG.md (v2.1.2): "Deprecated: ANTHROPIC_SMALL_FAST_MODEL is deprecated in favor of ANTHROPIC_DEFAULT_HAIKU_MODEL."
• Reference from model-config.md: The "Environment variables" table already lists ANTHROPIC_DEFAULT_HAIKU_MODEL as the standard, noting that ANTHROPIC_SMALL_FAST_MODEL is deprecated. The provider-specific guides simply haven't been synchronized with this change yet.