mcp-s3-v1.1.0

Dynamic Connection Management

This release adds runtime connection management to mcp-s3, enabling downstream projects like mcp-data-platform to dynamically add and remove S3 connections without restarting the server. This matches the pattern established by mcp-trino v1.2.0.

Highlights

Runtime Add/Remove Connections (#71)

The multiserver.Manager now supports fully thread-safe dynamic connection management:

// Add a new connection at runtime
err := manager.AddConnection(multiserver.ConnectionConfig{
    Name:     "data-lake",
    Region:   "eu-west-1",
    Endpoint: "https://s3.eu-west-1.amazonaws.com",
}, false)

// Replace an existing connection (closes old client, updates config)
err = manager.AddConnection(multiserver.ConnectionConfig{
    Name:   "data-lake",
    Region: "us-west-2",  // updated region
}, false)

// Remove a connection (closes client, removes config)
err = manager.RemoveConnection("data-lake")

New Public API

Addition	Package	Description
ConnectionManager interface	pkg/tools	Abstraction for dynamic connection management; satisfied by multiserver.Manager
WithConnectionManager() option	pkg/tools	Configures a Toolkit with a connection manager
Toolkit.RemoveClient()	pkg/tools	Removes a locally-added client by name

Thread Safety Improvements

All Manager read methods (ListConnections, HasConnection, DefaultConnectionName) now acquire RLock for safe concurrent access. The Toolkit delegates to the provider on each GetClient call (no stale client cache), so Manager.RemoveConnection takes immediate effect across all tool invocations.

Default Connection Protection

The default/primary connection is protected from both replacement and removal via AddConnection/RemoveConnection, preventing accidental disconnection of the bootstrap connection.

Behavioral Changes

Operation	v1.0.0	v1.1.0
AddConnection with existing name	Returns error	Replaces config, closes old client
AddConnection on default connection	Allowed	Returns error
RemoveConnection on default connection	Silently removes	Returns error
RemoveConnection on non-existent name	Silent no-op	Returns error
Manager read methods	No locking	RLock protected
Toolkit.GetClient via provider	Cached permanently in Toolkit	Delegated to provider each call

Dependency Updates

• github.com/modelcontextprotocol/go-sdk v1.3.1 → v1.4.1
• github.com/aws/aws-sdk-go-v2 group updated (multiple patches)
• golangci-lint updated
• CI action bumps: codecov, cosign-installer, codeql-action, deploy-pages, sbom-action, docker actions, setup-go

Installation

Homebrew (macOS)

brew install txn2/tap/mcp-s3

Claude Code CLI

claude mcp add s3 \
  -e AWS_REGION=us-east-1 \
  -e AWS_ACCESS_KEY_ID=your-key \
  -e AWS_SECRET_ACCESS_KEY=your-secret \
  -- mcp-s3

Docker

docker pull ghcr.io/txn2/mcp-s3:v1.1.0

Verification

All release artifacts are signed with Cosign:

cosign verify-blob --bundle mcp-s3_1.1.0_linux_amd64.tar.gz.sigstore.json \
  mcp-s3_1.1.0_linux_amd64.tar.gz

Full Changelog: v1.0.0...v1.1.0