microsoft/semantic-kernel · error · ServiceInitializationError

Failed to initialize the Amazon Bedrock Chat Completion…

Error message

Failed to initialize the Amazon Bedrock Chat Completion Service.

What it means

Raised during BedrockChatCompletion construction when BedrockSettings (chat_model_id, model_provider, env vars) fails Pydantic validation. This ServiceInitializationError is thrown before the Bedrock client is built; the original ValidationError is chained so the failing field is identifiable.

Solutions

Inspect the chained ValidationError (e.__cause__) to see which field failed.
Provide a valid chat_model_id and a supported model_provider (or let it be inferred from the model_id).
Verify env_file_path/encoding if loading config from a .env file.

Example fix

# before
service = BedrockChatCompletion(model_id="anthropic.claude", model_provider="nonsense")

# after
service = BedrockChatCompletion(model_id="anthropic.claude-3-sonnet", model_provider="anthropic")

Defensive patterns

Strategy: try-catch

Validate before calling

# Validate provider/model_id shape before constructing
SUPPORTED_PROVIDERS = {"anthropic", "amazon", "meta", "mistral", "ai21", "cohere", "stability"}
assert model_provider is None or model_provider in SUPPORTED_PROVIDERS, \
    f"model_provider must be one of {SUPPORTED_PROVIDERS}"

Try / catch

from semantic_kernel.exceptions import ServiceInitializationError
try:
    service = BedrockChatCompletion(model_id=model_id, model_provider=model_provider)
except ServiceInitializationError as e:
    print("Bedrock settings error:", e.__cause__)

Prevention

Use a supported model_provider value or omit it to infer from model_id.
Inspect __cause__ for the exact failing field.
Verify env file path if loading config from .env.

When it happens

Trigger: BedrockSettings validation fails — e.g. an invalid model_provider value (not one of the supported providers), a malformed env var, or conflicting/missing required configuration. The AWS client (runtime_client/client) is constructed separately; this error is specifically about settings parsing.

Common situations: Passing model_provider as an unsupported string; misconfigured .env (env_file_path wrong); version drift where BedrockSettings added a required field; typos in model_id or provider.

Related errors

AI-assisted analysis of microsoft/semantic-kernel@c028a0c7dc (2026-08-13). Data as JSON: /api/errors/df66e8871673bcbb. Report an issue: GitHub.

Appendix: source

Thrown at python/semantic_kernel/connectors/ai/bedrock/services/bedrock_chat_completion.py:87

        Args:
            model_id: The Amazon Bedrock chat model ID to use.
            model_provider: The Bedrock model provider to use.
            service_id: The Service ID for the completion service.
            runtime_client: The Amazon Bedrock runtime client to use.
            client: The Amazon Bedrock client to use.
            env_file_path: The path to the .env file.
            env_file_encoding: The encoding of the .env file.
        """
        try:
            bedrock_settings = BedrockSettings(
                chat_model_id=model_id,
                model_provider=model_provider,
                env_file_path=env_file_path,
                env_file_encoding=env_file_encoding,
            )
        except ValidationError as e:
            raise ServiceInitializationError("Failed to initialize the Amazon Bedrock Chat Completion Service.") from e

        if bedrock_settings.chat_model_id is None:
            raise ServiceInitializationError("The Amazon Bedrock Chat Model ID is missing.")

        super().__init__(
            ai_model_id=bedrock_settings.chat_model_id,
            service_id=service_id or bedrock_settings.chat_model_id,
            runtime_client=runtime_client,
            client=client,
            bedrock_model_provider=bedrock_settings.model_provider,
        )

    # region Overriding base class methods

    # Override from AIServiceClientBase
    @override
    def get_prompt_execution_settings_class(self) -> type["PromptExecutionSettings"]:
        return BedrockChatPromptExecutionSettings

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