Amazon Bedrock

The Converse API over AWS event-stream framing, with API-key auth.

let model = BedrockModel(
  "anthropic.claude-sonnet-4-5-20250929-v1:0",
  region: "us-east-1"
)

Key from AWS_BEARER_TOKEN_BEDROCK — Bedrock's API-key auth, no SigV4 signing or credential chain needed. The base URL derives from the region (https://bedrock-runtime.{region}.amazonaws.com) unless you pass one.

Features

  • Tools, structured output, and vision over the Converse API.
  • Responses stream in AWS's binary event-stream framing; the library decodes it natively.
  • usage.cachedInputTokens is populated where the model reports cache reads.

Models

The reasoning parameter translates by model-id family:

FamilyTranslation
anthropic.*Claude thinking config — the same adaptive/budget tiers as the Anthropic pack
openai.*reasoning_effort
everything elseGeneric reasoningConfig.maxReasoningEffort (xhigh becomes max)

Model ids are Bedrock's prefixed forms, e.g. anthropic.claude-sonnet-4-5-20250929-v1:0 or an inference profile like us.anthropic.claude-sonnet-4-5-20250929-v1:0. Amazon's own Nova line (as of July 2026): nova-2-lite (December 2025), plus nova-pro, nova-lite, and nova-micro.

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