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Python dependency commands on this page use a PM-prepared source checkout. After a dependency change, reactivate the checkout and restart Mibyan. Mibyan supports Amazon Bedrock as a native provider. This gives you full access to the Bedrock ecosystem: IAM authentication, Guardrails, cross-region inference profiles, and all foundation models. Mibyan routes each model family through the API that serves it best: All three routes share the same AWS credential chain and region resolution — no separate configuration is needed. Requests to the Mantle endpoint are authenticated with AWS_BEARER_TOKEN_BEDROCK when set, or SigV4-signed via the standard boto3 credential chain otherwise.

Prerequisites

  • AWS credentials — any source supported by the boto3 credential chain:
    • IAM instance role (EC2, ECS, Lambda — zero config)
    • AWS_ACCESS_KEY_ID + AWS_SECRET_ACCESS_KEY environment variables
    • AWS_PROFILE for SSO or named profiles
    • aws configure for local development
  • boto3 — install with cd ~/.mibyan/mibyan-agent && python -c "import pm; pm.sync_venv(['bedrock'], explicit=True)"
  • IAM permissions — at minimum:
    • bedrock:InvokeModel and bedrock:InvokeModelWithResponseStream (for inference)
    • bedrock:ListFoundationModels and bedrock:ListInferenceProfiles (for model discovery)
    • bedrock:GetInferenceProfile (only if model.default is an application inference profile ARN — used to size the context window from the wrapped model)
EC2 / ECS / LambdaOn AWS compute, attach an IAM role with AmazonBedrockFullAccess and you’re done. No API keys, no .env configuration — Mibyan detects the instance role automatically.

Quick Start

Configuration

After running mibyan model, your ~/.mibyan/config.yaml will contain:

Region

Set the AWS region in any of these ways (highest priority first):
  1. bedrock.region in config.yaml
  2. AWS_REGION environment variable
  3. AWS_DEFAULT_REGION environment variable
  4. Default: us-east-1

Guardrails

To apply Amazon Bedrock Guardrails to all model invocations:
The guardrail is attached on the Converse route (guardrailConfig) and on the Claude route (InvokeModel headers via the Anthropic Bedrock SDK, so prompt caching and thinking are kept). A blocked request surfaces as a content-filter refusal rather than as model text. stream_processing_mode only applies to Converse. AWS does not apply Guardrails to the Mantle Responses endpoint used by openai.gpt-5.x models (AWS docs); use a Converse-served model when a guardrail is required.

Model Discovery

Mibyan auto-discovers available models via the Bedrock control plane. You can customize discovery:

Prompt caching (cachePoint)

Mibyan automatically applies prompt caching on the Bedrock Converse API path by inserting cachePoint markers after the system prompt, tool definitions, and the latest message. Because sending a cachePoint block to a model that doesn’t support it raises a ValidationException, markers are only added for models on a known-good allowlist (Anthropic Claude and Amazon Nova model IDs); unknown models default to no cache markers. Claude models normally use the AnthropicBedrock SDK path, which has its own prompt caching — the Converse cachePoint path covers Nova and the bearer-token Claude fallback. No configuration needed; cache reads/writes show up in usage accounting.

Context-window probing

For models whose context window isn’t in Mibyan’ static table, Mibyan can probe the real limit by sending oversized requests at fixed tiers (~1.3M and ~2.2M tokens) and parsing the maximum reported in Bedrock’s length-validation error. Probed values feed the same metadata cache as the static table; stale cached entries that under-report a model’s window (e.g. entries seeded before a model’s 1M window went GA) are dropped automatically in favor of the larger known value. Application inference profiles. An ARN such as arn:aws:bedrock:us-west-2:123456789012:application-inference-profile/abcdef123456 names no model, so neither the probe nor the static table can size it. Mibyan calls bedrock:GetInferenceProfile in the ARN’s region and sizes the window from the model the profile wraps (1M for a profile wrapping Claude Sonnet 4.6). Without that permission the 128,000-token default applies and a WARNING names the profile; set model.context_length explicitly to override either way.

Available Models

Bedrock models use inference profile IDs for on-demand invocation. The mibyan model picker shows these automatically, with recommended models at the top:
Cross-Region InferenceModels prefixed with us. use cross-region inference profiles, which provide better capacity and automatic failover across AWS regions. Models prefixed with global. route across all available regions worldwide. OpenAI openai.* model IDs are served by Bedrock Mantle in the configured region and don’t use inference-profile prefixes.

Switching Models Mid-Session

Use the /model command during a conversation:

Diagnostics

The doctor checks:
  • Whether AWS credentials are available (env vars, IAM role, SSO)
  • Whether boto3 is installed
  • Whether the Bedrock API is reachable (ListFoundationModels)
  • Number of available models in your region

Gateway (Messaging Platforms)

Bedrock works with all Mibyan gateway platforms (Telegram, Discord, Slack, Feishu, etc.). Configure Bedrock as your provider, then start the gateway normally:
The gateway reads config.yaml and uses the same Bedrock provider configuration.

Troubleshooting

”No API key found” / “No AWS credentials”

Mibyan checks for credentials in this order:
  1. AWS_BEARER_TOKEN_BEDROCK
  2. AWS_ACCESS_KEY_ID + AWS_SECRET_ACCESS_KEY
  3. AWS_PROFILE
  4. EC2 instance metadata (IMDS)
  5. ECS container credentials
  6. Lambda execution role
If none are found, run aws configure or attach an IAM role to your compute instance.

”Invocation of model ID … with on-demand throughput isn’t supported”

Use an inference profile ID (prefixed with us. or global.) instead of the bare foundation model ID. For example:
  • ❌ anthropic.claude-sonnet-4-6
  • ✅ us.anthropic.claude-sonnet-4-6

”ThrottlingException”

You’ve hit the Bedrock per-model rate limit. Mibyan automatically retries with backoff. To increase limits, request a quota increase in the AWS Service Quotas console.

One-Click AWS Deployment

For a fully automated deployment on EC2 with CloudFormation: sample-mibyan-agent-on-aws-with-bedrock — creates VPC, IAM role, EC2 instance, and configures Bedrock automatically. Deploy in any region with one click.