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MediaStore Configuration

Configure where media files are stored — local filesystem or S3-compatible storage.

Overview

MediaStore is the storage abstraction behind all multimodal operations. When a tool uploads media via upload_media() or MediaResult, it goes to the configured MediaStore. When an LLM needs to resolve a resource_link, it fetches from the same store.

Two backends are available:

Backend Best For URI Format
Local (default) Development, single-machine file:///tmp/mcp-mesh-media/media/chart.png
S3 Production, multi-agent s3://mcp-mesh-media/media/chart.png

Local Filesystem (Default)

No configuration needed for development. Files are stored at /tmp/mcp-mesh-media/media/ by default.

# Optional — customize the path
export MCP_MESH_MEDIA_STORAGE=local
export MCP_MESH_MEDIA_STORAGE_PATH=/var/lib/mcp-mesh-media
export MCP_MESH_MEDIA_STORAGE_PREFIX=media/

Shared Storage for Multi-Agent

When running multiple agents locally, they all share the same filesystem, so local storage works out of the box. In Docker or Kubernetes, use S3 or a shared volume.

S3 / S3-Compatible (Production)

For production deployments with MinIO, AWS S3, or any S3-compatible service:

export MCP_MESH_MEDIA_STORAGE=s3
export MCP_MESH_MEDIA_STORAGE_BUCKET=mcp-mesh-media
export MCP_MESH_MEDIA_STORAGE_ENDPOINT=http://minio:9000  # omit for AWS
export MCP_MESH_MEDIA_STORAGE_PREFIX=media/
# Standard AWS credentials
export AWS_ACCESS_KEY_ID=minioadmin
export AWS_SECRET_ACCESS_KEY=minioadmin

mesh:
  media:
    storage: s3
    storageBucket: mcp-mesh-media
    storageEndpoint: http://minio:9000
    storagePrefix: media/

services:
  minio:
    image: minio/minio:latest
    command: server /data --console-address ":9001"
    ports:
      - "9000:9000"
      - "9001:9001"
    environment:
      MINIO_ROOT_USER: minioadmin
      MINIO_ROOT_PASSWORD: minioadmin

S3 Dependencies

pip install boto3

npm install @aws-sdk/client-s3

The SDK lazy-loads @aws-sdk/client-s3 only when the S3 backend is configured.

S3 client is included in mcp-mesh-spring-boot-starter. No additional dependency needed.

Environment Variables

Variable Default Description
MCP_MESH_MEDIA_STORAGE local Backend: local or s3
MCP_MESH_MEDIA_STORAGE_PATH /tmp/mcp-mesh-media Local filesystem base path
MCP_MESH_MEDIA_STORAGE_BUCKET mcp-mesh-media S3 bucket name
MCP_MESH_MEDIA_STORAGE_ENDPOINT (none) S3-compatible endpoint URL
MCP_MESH_MEDIA_STORAGE_PREFIX media/ Key/directory prefix

Security

  • Path traversal protection — Local storage validates all paths against directory traversal attacks
  • S3 credentials — Use IAM roles or environment variables; never hardcode
  • Storage isolation — Each deployment's media is isolated by the configured prefix

See Also