bedrock-multi-model-mcp

MCP server for AWS Bedrock - text, image, and video generation from any model. Use Claude, Llama, Mistral, Nova, Qwen, DeepSeek, GPT-OSS, and more from Claude Code (or any MCP client).

Tools

Tool	Description
bedrock_ask	Send a prompt to any text model. Returns response with token counts and latency.
bedrock_compare	Same prompt to 2-5 models side by side. Compare quality, speed, and style.
bedrock_list_models	List available text models with aliases, use cases, and capabilities.
bedrock_generate_image	Generate images from text (Stable Image Ultra, SD3.5 Large, Stable Image Core). Saves PNG locally.
bedrock_generate_video	Start async video generation (Luma Ray 2). Output to S3.
bedrock_video_status	Check video generation job progress.
bedrock_embed_similarity	Embed 2+ texts (Titan, Cohere) and return a cosine-similarity matrix.

Supported Models

Model data lives in src/data/ (text-models.json, image-models.json, video-models.json, embedding-models.json) - edit those files to add or remove models without touching code.

Text (Converse API)

Provider	Models	Aliases
Anthropic	Claude Fable 5.1, Opus 5, Sonnet 5, Haiku 4.5 (current); Fable 5, Opus 4.8 / 4.7 / 4.6, Sonnet 4.6 (previous-gen)	fable, claude-opus, claude-sonnet, claude-haiku
Meta	Llama 4 Maverick, Llama 4 Scout, Llama 3.3 70B	llama4, llama4-scout, llama3.3
Mistral	Mistral Large 3, Devstral 2, Mistral Small, Pixtral Large	mistral-large, devstral, mistral-small, pixtral
Amazon	Nova Pro, Nova 2 Lite, Nova Lite, Nova Micro	nova-pro, nova2-lite, nova-lite, nova-micro
Qwen	Qwen3 Coder Next, Qwen3 VL 235B	qwen-coder, qwen-vl
DeepSeek	DeepSeek V3.2, DeepSeek R1	deepseek, deepseek-r1
OpenAI	GPT-OSS 120B, GPT-OSS 20B	gpt-oss, gpt-oss-20b

Bare-tier aliases (fable, claude-opus, claude-sonnet, claude-haiku) track the current model in that tier; version-pinned aliases (fable-5, claude-opus-4.8, claude-sonnet-4.6) keep the previous generation reachable. As of 2026-09-06 Anthropic's current lineup is Claude Fable 5.1, Opus 5, Sonnet 5 and Haiku 4.5, and its models overview lists the 4.x Opus / Sonnet entries and Fable 5 under "Legacy models (still available)".

temperature is the one thing that differs across those entries. Anthropic deprecated temperature / top_p / top_k for Claude Opus 4.7 and later, where a non-default value returns a 400, so text-models.json marks those entries noTemperature and this server omits the parameter for them - the temperature argument is accepted but has no effect. Claude Haiku 4.5, Opus 4.6 and Sonnet 4.6 still honor it, so pin claude-sonnet-4.6 or use claude-haiku if you need to set it.

The maxTokens value in text-models.json is the default output cap this server sends when a call omits max_tokens - deliberately below the model's own ceiling (Anthropic documents 128K max output for Fable 5.1, Opus 5 and Sonnet 5, 64K for Haiku 4.5). Pass max_tokens to go higher on a single call.

Image (InvokeModel API)

Model	Alias	Region
Stable Image Ultra (default)	stable-ultra	us-west-2
Stable Diffusion 3.5 Large	sd3.5	us-west-2
Stable Image Core	stable-core	us-west-2

Stability models take an aspect ratio, not pixel dimensions. The width and height arguments only select the closest supported ratio (1:1, 16:9, 9:16, 3:2, 2:3, 4:5, 5:4, 21:9, 9:21); the model picks the output pixels. The size reported by bedrock_generate_image is read back out of the saved PNG, so it is the real output size rather than what you asked for.

Video (Async API)

Model	Alias	Duration	Resolution	Region
Luma Ray 2	luma-ray, ray2	5s or 9s	720p	us-west-2

The output S3 bucket must be in us-west-2 (same region as the model).

Amazon Nova Canvas/Reel and Titan Image were removed when AWS marked them end-of-life (Nova Reel EOL 2026-09-30); the registry only ships ACTIVE models.

Embeddings (InvokeModel API)

Model	Alias	Dimensions
Amazon Titan Text Embeddings V2	titan-v2	1024
Amazon Titan Text Embeddings V1	titan-v1	1536
Amazon Titan Multimodal Embeddings	titan-multimodal	1024
Cohere Embed English v3	cohere-en	1024
Cohere Embed Multilingual v3	cohere-multi	1024

bedrock_embed_similarity only sends text, so Titan Multimodal is exercised through its text path here and behaves like titan-v2 at the same 1024 dimensions.

You can also pass any valid Bedrock model ID directly. Note: many foundation models require a cross-region inference profile (us. prefix) for on-demand invocation - the registry uses the working form for each model.

Model availability varies by region and account. The registry IDs are verified working in us-east-1, but individual models may not be enabled in your region or granted to your account. Models you can't access return a clear error (per-model in bedrock_compare); the rest still work. Enable models in the AWS Console under Bedrock > Model access.

Setup

Prerequisites

• Node.js >= 22 (Node 20 reached end of life on 2026-04-30; CI runs 22, 24 and 26)
• AWS credentials configured (bearer token, env vars, ~/.aws/credentials, SSO, or IAM role)
• Bedrock model access enabled in your AWS account (request access in the AWS Console under Bedrock > Model access)

Install and Build

git clone https://github.com/Sagargupta16/bedrock-multi-model-mcp.git
cd bedrock-multi-model-mcp
npm install
npm run build

Configure in Claude Code

Add to your Claude Code MCP settings (~/.claude.json):

{
  "mcpServers": {
    "bedrock": {
      "command": "node",
      "args": ["/path/to/bedrock-multi-model-mcp/dist/index.js"],
      "env": {
        "AWS_BEARER_TOKEN_BEDROCK": "ABSK...",
        "AWS_REGION": "us-east-1"
      }
    }
  }
}

Configure in Claude Desktop

Same server block, in claude_desktop_config.json:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json

{
  "mcpServers": {
    "bedrock": {
      "command": "node",
      "args": ["/path/to/bedrock-multi-model-mcp/dist/index.js"],
      "env": {
        "AWS_BEARER_TOKEN_BEDROCK": "ABSK...",
        "AWS_REGION": "us-east-1",
        "BEDROCK_MCP_OUTPUT_DIR": "C:\\Users\\you\\bedrock-images"
      }
    }
  }
}

Set BEDROCK_MCP_OUTPUT_DIR explicitly for Desktop: on Windows it spawns the server from a write-protected directory (C:\Windows\System32), so the default "save next to cwd" behavior cannot apply and generated images fall back to ~/bedrock-images/.

Environment Variables

Variable	Default	Description
AWS_REGION	us-east-1	AWS region for Bedrock API calls
AWS_DEFAULT_REGION	-	Fallback region, used only when AWS_REGION is unset
AWS_BEARER_TOKEN_BEDROCK	-	Bedrock API Key bearer token (recommended)
AWS_ACCESS_KEY_ID	-	AWS access key (if not using bearer token/SSO)
AWS_SECRET_ACCESS_KEY	-	AWS secret key (if not using bearer token/SSO)
AWS_PROFILE	-	Named AWS profile from ~/.aws/credentials
BEDROCK_MCP_OUTPUT_DIR	cwd (or ~/bedrock-images if cwd is not writable)	Default output directory for generated images. Overridden by the output_dir tool arg. Directory is auto-created.

Authentication

The server supports two auth methods:

1. Bedrock API Key (bearer token) - Set AWS_BEARER_TOKEN_BEDROCK. The SDK (v3.840.0+) reads this automatically. If the SDK fails, falls back to raw HTTP with Authorization: Bearer header.
2. IAM credentials - Standard AWS credential chain (env vars, profile, SSO, IAM role).

Usage Examples

Ask a single model

"Use bedrock_ask to ask llama4 to explain Docker in 3 sentences"

Compare models

"Use bedrock_compare with llama4, nova-pro, and mistral-large: What are the pros and cons of microservices?"

bedrock_compare runs one full generation per model in the list, and each one is billed independently - three models is three generations, five is five. This server adds no markup and sets no rates; billing is entirely AWS Bedrock's, per model and per token. Current rates: AWS Bedrock pricing and, for the Claude models, Anthropic pricing.

Generate an image

"Use bedrock_generate_image with stable-ultra: A futuristic Tokyo street at night, neon lights, rain"

Generate a video

"Use bedrock_generate_video: Closeup of ocean waves crashing on rocks at sunset, s3_uri: s3://my-bucket/videos/"

Compare text similarity

"Use bedrock_embed_similarity to compare: 'a cat', 'a kitten', 'a car'"

Architecture

src/
  index.ts          # MCP server - tool registration, stdio transport
  models.ts         # Loads + validates text-model data, resolves aliases
  types.ts          # Zod schemas for model data validation
  bedrock/
    client.ts       # Shared region/auth config + raw HTTP fallback
    converse.ts     # Converse API wrapper (text models)
    image.ts        # InvokeModel wrapper (image models)
    video.ts        # Async invoke wrapper (video models)
    embed.ts        # InvokeModel wrapper (embeddings) + cosine similarity
  data/
    text-models.json       # Text model registry (data, not code)
    image-models.json      # Image model registry
    video-models.json      # Video model registry
    embedding-models.json  # Embedding model registry

Model definitions are data, kept in src/data/*.json and validated against Zod schemas at load time, so the catalog can be updated without changing logic. The build copies these JSON files into dist/data/.

• Text: Uses the Converse API - unified interface across all text models
• Image: Uses InvokeModel with model-specific request formats (handled internally)
• Video: Uses StartAsyncInvoke - requires S3 bucket for output

Troubleshooting

Error	Cause	Fix
The provided model identifier is invalid.	The ID does not resolve on Bedrock - usually a missing us. cross-region inference profile prefix, or a model that is not offered in your region.	Use a registry alias (bedrock_list_models), or add the us. prefix to the full ID.
`temperature` is deprecated for this model.	A Claude 4.7-or-later model was reached without a registry entry, so the server sent its default temperature of 0.7. Anthropic deprecated temperature / top_p / top_k for Claude Opus 4.7 and later, and a non-default value returns a 400 there. Earlier models (Haiku 4.5, Opus 4.6, Sonnet 4.6) still accept it.	Call it through a registered alias, or add a registry entry with "noTemperature": true in src/data/text-models.json.
AccessDeniedException	Model access has not been granted to your account.	AWS Console > Bedrock > Model access, request the model, retry once it shows Access granted.
bedrock_video_status reports Failed	Bedrock returns the reason on the job itself.	Read the Reason: line printed under the status and fix what it names.

Error strings are surfaced verbatim from Bedrock. Note that the temperature one is a registry gap in this server, not an IAM or model-access problem - there is nothing to fix in AWS for it.

Contributing

See CONTRIBUTING.md for setup, the two required checks, and the rules for adding a model (registry data + a test assertion + a live probe of the model ID). Security issues go through the private route in SECURITY.md, not a public issue.

License

MIT