[NEW CONTENT] Bedrock `guardrail_latest_message`

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Proposed Content

Update the bedrock model page to cover the guardrail_latest_message parameter added in this commit: strands-agents/sdk-python@08bf563

Location

https://strandsagents.com/latest/documentation/docs/user-guide/concepts/model-providers/amazon-bedrock/

Rationale

Missing functionality

Content Outline (Optional)

No response

References

No response

---

Implementation Requirements

Based on analysis of the referenced commit and existing documentation structure.

New Parameter Details

Parameter	Type	Default	Description
guardrail_latest_message	Optional[bool]	False	When enabled, sends only the latest user message to guardrails instead of the entire conversation

Technical Behavior

When guardrail_latest_message=True:

• Only the last user message is evaluated by guardrails
• Text content is wrapped as: {"guardContent": {"text": {"text": "message"}}}
• Image content is wrapped as: {"guardContent": {"image": {...}}}
• Earlier messages in the conversation are not evaluated by guardrails

Use Cases

This parameter is useful when:

• Performance optimization: Evaluate less content per request
• Cost reduction: Fewer tokens processed by guardrails
• Targeted checking: Only evaluate the newest user input, trusting that previous messages have already been validated

Files to Modify

1. docs/user-guide/concepts/model-providers/amazon-bedrock.md
   • Add guardrail_latest_message parameter to the Guardrails section (around line 421-431)
   • Include the parameter in the existing code example with a brief comment explaining its purpose

Documentation Changes

Update the existing Guardrails code example in amazon-bedrock.md to include the new parameter:

# Using guardrails with BedrockModel
bedrock_model = BedrockModel(
    model_id="anthropic.claude-sonnet-4-20250514-v1:0",
    guardrail_id="your-guardrail-id",
    guardrail_version="DRAFT",
    guardrail_trace="enabled",  # Options: "enabled", "disabled", "enabled_full"
    guardrail_stream_processing_mode="sync",  # Options: "sync", "async"
    guardrail_redact_input=True,  # Default: True
    guardrail_redact_input_message="Blocked Input!",
    guardrail_redact_output=False,  # Default: False
    guardrail_redact_output_message="Blocked Output!",
    guardrail_latest_message=True,  # Only evaluate the latest user message (default: False)
)

Add a brief explanation below the code block:

Note: When guardrail_latest_message=True, only the most recent user message is sent to guardrails for evaluation. This can improve performance and reduce costs in multi-turn conversations where earlier messages have already been validated.

Acceptance Criteria

• guardrail_latest_message parameter is documented in the Guardrails section of amazon-bedrock.md
• Code example includes the new parameter with a descriptive comment
• Brief explanation of when/why to use this parameter is included
• Documentation builds successfully with mkdocs build
• Parameter name and behavior matches the SDK implementation

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/strands

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/strands

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/strands implement