mcp-storage

Universal cloud storage MCP server — manage files across AWS S3, Google Cloud Storage, Cloudflare R2, MinIO, and any S3-compatible provider through a single interface. 12 tools for listing, uploading, downloading, copying, moving, and searching objects.

Installation

cargo install mcp-storage

Provider Setup

AWS S3

No extra config needed if you have ~/.aws/credentials set up:

mcp-storage

Or with explicit credentials:

STORAGE_ACCESS_KEY=AKIA... STORAGE_SECRET_KEY=... STORAGE_REGION=us-east-1 mcp-storage

Google Cloud Storage

GCS works via S3 interoperability. Create HMAC keys first:

# Create HMAC key (one-time setup)
gcloud storage hmac create YOUR-SERVICE-ACCOUNT@PROJECT.iam.gserviceaccount.com

# Run with GCS
STORAGE_ENDPOINT=https://storage.googleapis.com \
STORAGE_ACCESS_KEY=GOOG1E... \
STORAGE_SECRET_KEY=... \
STORAGE_REGION=us-east-1 \
mcp-storage

Note: GCS S3 interop doesn't support list_buckets. Use list_objects with a specific bucket name.

Cloudflare R2

STORAGE_ENDPOINT=https://ACCOUNT_ID.r2.cloudflarestorage.com \
STORAGE_ACCESS_KEY=... \
STORAGE_SECRET_KEY=... \
STORAGE_REGION=auto \
mcp-storage

Get R2 credentials from: Cloudflare Dashboard → R2 → Manage R2 API Tokens.

MinIO (Self-hosted)

STORAGE_ENDPOINT=http://localhost:9000 \
STORAGE_ACCESS_KEY=minioadmin \
STORAGE_SECRET_KEY=minioadmin \
mcp-storage

DigitalOcean Spaces

STORAGE_ENDPOINT=https://nyc3.digitaloceanspaces.com \
STORAGE_ACCESS_KEY=... \
STORAGE_SECRET_KEY=... \
STORAGE_REGION=nyc3 \
mcp-storage

Backblaze B2

STORAGE_ENDPOINT=https://s3.us-west-004.backblazeb2.com \
STORAGE_ACCESS_KEY=... \
STORAGE_SECRET_KEY=... \
STORAGE_REGION=us-west-004 \
mcp-storage

MCP Client Configuration

Claude Desktop

{
  "mcpServers": {
    "storage": {
      "command": "mcp-storage",
      "env": {
        "STORAGE_ENDPOINT": "https://storage.googleapis.com",
        "STORAGE_ACCESS_KEY": "GOOG1E...",
        "STORAGE_SECRET_KEY": "your-secret",
        "STORAGE_REGION": "us-east-1"
      }
    }
  }
}

Cursor

Add to .cursor/mcp.json:

{
  "mcpServers": {
    "storage": {
      "command": "mcp-storage",
      "env": {}
    }
  }
}

If using AWS with default credentials (~/.aws/credentials), no env vars needed.

Tools (12)

Browse & Read

| Tool | Description | Example | |------|-------------|---------| | list_buckets | List all buckets | "Show me all my S3 buckets" | | list_objects | List objects with prefix filter | "List files in my-bucket/images/" | | get_object_info | Get size, type, last modified | "What's the size of report.pdf?" | | download_object | Get file content (text inline, binary as base64) | "Show me config.json" | | generate_presigned_url | Create temporary download link | "Give me a link to share this file" | | search_objects | Find files by prefix pattern | "Find all .csv files in data/" | | get_storage_usage | Total size and count for a bucket | "How much storage am I using?" |

Write (Gated)

| Tool | Approval | Description | Example | |------|:--------:|-------------|---------| | upload_object | No | Upload text content | "Save this JSON to config/app.json" | | copy_object | No | Copy within/between buckets | "Copy report.pdf to the archive bucket" | | move_object | Yes | Move (copy + delete source) | "Move old logs to cold storage" | | delete_object | Yes | Delete a single object | "Delete the test file" | | create_bucket | Yes | Create a new bucket | "Create a bucket called backups" |

Usage Examples

List what's in a bucket

Agent: "What files are in my data-pipeline bucket?"
→ list_objects(bucket="data-pipeline", prefix="output/", limit=20)

Result:
  output/report-2026-05-01.csv (2.3 MB)
  output/report-2026-05-02.csv (2.1 MB)
  output/summary.json (4.2 KB)

Upload a file

Agent: "Save this analysis to my reports bucket"
→ upload_object(bucket="reports", key="2026/q2-analysis.md", content="# Q2 Analysis\n...")

Result: uploaded, etag="abc123"

Generate a shareable link

Agent: "I need a download link for the quarterly report, valid for 1 hour"
→ generate_presigned_url(bucket="reports", key="2026/q2-report.pdf", expires_in=3600)

Result: https://s3.amazonaws.com/reports/2026/q2-report.pdf?X-Amz-Signature=...

Search for files

Agent: "Find all CSV files from May"
→ search_objects(bucket="data-pipeline", pattern="output/2026-05")

Result:
  output/2026-05-01.csv
  output/2026-05-02.csv
  ...

Check storage usage

Agent: "How much space is my logs bucket using?"
→ get_storage_usage(bucket="application-logs")

Result: 142,847 objects, 23.4 GB total

Environment Variables

| Variable | Required | Default | Description | |----------|:--------:|---------|-------------| | STORAGE_ENDPOINT | No | AWS S3 | Custom endpoint URL | | STORAGE_ACCESS_KEY | No* | — | Access key ID | | STORAGE_SECRET_KEY | No* | — | Secret access key | | STORAGE_REGION | No | us-east-1 | Region |

*If not set, uses AWS default credential chain (~/.aws/credentials, AWS_ACCESS_KEY_ID/AWS_SECRET_ACCESS_KEY env vars, IAM roles).

Security

Write operations are gated — delete_object, move_object, and create_bucket require approval in governed environments
Presigned URLs expire — default 1 hour, configurable per request
No secrets in responses — credentials are never echoed back
Read-only by default — browse and download tools don't modify anything

Tested Providers

| Provider | list_buckets | list_objects | upload | download | delete | presigned | |----------|:---:|:---:|:---:|:---:|:---:|:---:| | AWS S3 | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | | Google Cloud Storage | ❌* | ✅ | ✅ | ✅ | ✅ | ✅ | | Cloudflare R2 | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | | MinIO | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ |

*GCS S3 interop doesn't support ListBuckets — use list_objects with a known bucket name.

License

Apache-2.0

MCP Servers