dynamic-mcp
MCP proxy server that reduces LLM context overhead by grouping tools from multiple upstream MCP servers and loading tool schemas on-demand.
Instead of requiring you to expose all MCP servers upfront (which can consume thousands of tokens), dynamic-mcp exposes only two MCP tools initially.
It supports tool functionality of upstream MCP servers, stdio, HTTP, and SSE transports, handles OAuth, and automatically retries failed connections.
Quick Start
Installation
Option 1: Python package
Use uvx to run the PyPI package in your agent's MCP settings:
You can set the DYNAMIC_MCP_CONFIG environment variable and omit the config path.
Option 2: Native binary
Download a release for
your operating system and put dmcp in your PATH:
Set the DYNAMIC_MCP_CONFIG environment variable and omit the args altogether.
Option 3: Compile from source
Install from crates.io:
cargo install dynamic-mcp
The binary is then available at ~/.cargo/bin/dmcp ($CARGO_HOME/bin/dmcp).
Import from AI Coding Tools
Dynamic-mcp can automatically import MCP server configurations from popular AI coding tools.
Supported Tools (<tool-name>):
- Cursor (
cursor) - OpenCode (
opencode) - Claude Desktop (
claude-desktop) - Claude Code CLI (
claude) - Visual Studio Code (
vscode) - Cline (
cline) - KiloCode (
kilocode) - Codex CLI (
codex) - Gemini CLI (
gemini) - Google Antigravity (
antigravity)
Quick Start
Import from project config (run in project directory):
Import from global/user config:
Force overwrite (skip confirmation prompt):
The command will:
- Detect your tool's config location
- Parse the existing MCP servers
- Interactively prompt for descriptions
- Normalize environment variable formats
- Generate
dynamic-mcp.json
Example Import
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Tool-Specific Notes
- Cursor: Supports both
.cursor/mcp.json(project) and~/.cursor/mcp.json(global) - Claude Desktop: Global config only, location varies by OS:
- macOS:
~/Library/Application Support/Claude/claude_desktop_config.json - Windows:
%APPDATA%\Claude\claude_desktop_config.json - Linux:
~/.config/Claude/claude_desktop_config.json
- macOS:
- Claude Code CLI: Supports both
.mcp.json(project root) and~/.claude.json(user/global) - Gemini CLI: Supports both
.gemini/settings.json(project) and~/.gemini/settings.json(global) - VS Code: Supports both
.vscode/mcp.json(project) and user-level config (OS-specific paths) - OpenCode: Supports both JSON and JSONC formats (JSON with comments)
- Codex CLI: Global only - uses TOML format (
~/.codex/config.toml) - Antigravity: Global only -
~/.gemini/antigravity/mcp_config.json
Environment Variable Conversion
The import command automatically normalizes environment variables to dynamic-mcp's ${VAR} format:
| Tool | Original Format | Converted To |
|---|---|---|
| Cursor | ${env:GITHUB_TOKEN} |
${GITHUB_TOKEN} |
| Claude Desktop | ${GITHUB_TOKEN} |
${GITHUB_TOKEN} |
| Claude Code CLI | ${GITHUB_TOKEN} |
${GITHUB_TOKEN} |
| VS Code | ${env:GITHUB_TOKEN} |
${GITHUB_TOKEN} |
| Codex | "${GITHUB_TOKEN}" |
${GITHUB_TOKEN} |
Note: VS Code's ${input:ID} secure prompts cannot be automatically converted. You'll need to manually configure these after import.
See docs/IMPORT.md for detailed tool-specific import guides.
Dynamic MCP format
Calling upstream servers on demand
Create a dynamic-mcp.json file with a description field for each server:
Environment Variables
It supports the ${VAR} syntax for environment variable interpolation:
Server Types
It supports all standard MCP transport mechanisms.
stdio (Default)
http
sse
OAuth Authentication (HTTP/SSE)
OAuth Flow:
- On first connection, a browser opens for authorization
- Access tokens are stored in
~/.dynamic-mcp/oauth-servers/<server-name>.json - Automatic token refresh before expiry (with RFC 6749 token rotation support)
- The token is injected as an
Authorization: Bearer <token>header
Troubleshooting
Server Connection Issues
Problem: ❌ Failed to connect to <server>
Solutions:
- Automatic retry: The system retries up to 3 times with exponential backoff (2s, 4s, 8s)
- Periodic retry: Failed servers are retried every 30 seconds in the background
- Stdio servers: Verify command exists (
which <command>) - HTTP/SSE servers: Check that the server is running and the URL is correct
- Environment variables: Ensure all
${VAR}references are defined - OAuth servers: Complete OAuth flow when prompted
Logging:
By default, errors and warnings are logged to the terminal. For more verbose output:
# Debug mode (all logs including debug-level details)
RUST_LOG=debug
# Info mode (includes informational messages)
RUST_LOG=info
# Default mode (errors and warnings only, no RUST_LOG needed)
OAuth Authentication Problems
Problem: The browser doesn't open for OAuth
Solutions:
- Manually open the URL shown in the console
- Check that the firewall allows localhost connections
- Verify
oauth_client_idis correct for the server
Problem: Token refresh fails
Solutions:
- Delete cached token:
rm ~/.dynamic-mcp/oauth-servers/<server-name>.json - Re-authenticate on next connection
Environment Variable Not Substituted
Problem: Config shows ${VAR} instead of value
Solutions:
- Use
${VAR}syntax, not$VAR - Export variable:
export VAR=value - Variable names are case-sensitive
- Check for typos in variable name
Configuration Errors
Problem: Invalid JSON in config file
Solutions:
- Validate JSON syntax (use
jq . config.json) - Check for trailing commas
- Ensure all required fields are present (
descriptionis always required;typeis required only for http/sse servers)
Problem: Failed to resolve config path
Solutions:
- Use an absolute path or a path relative to the working directory
- Check that the file exists and has read permissions
- Try:
ls -la <config-path>
Tool Call Failures
Problem: Tool call returns error
Debugging:
- Test the tool directly with the upstream server
- Check that the tool name and arguments match the schema
- Verify the group name is correct
- Enable debug logging to see JSON-RPC messages
Performance Issues
Problem: Slow startup
Solutions:
- Parallel connections already enabled
- Check network latency for HTTP/SSE servers
- Some servers may be slow to initialize (normal)
Problem: High memory usage
Solutions:
- Tools are cached in memory (expected)
- Failed groups use minimal memory
- Large tool schemas contribute to memory usage
Building from source
Rust Binary
To build the Rust binary directly:
The binary is then available at ./target/release/dmcp.
Python Package
To build the Python package (wheel):
# Build wheel
# Install locally
The Python package uses maturin with bindings = "bin" to compile the Rust binary directly into the wheel.
Contributing
For instructions on development setup, testing, and contributing, see CONTRIBUTING.md.
Release History
See CHANGELOG.md for version history and release notes.
Acknowledgments
- TypeScript implementation: modular-mcp
- MCP Specification: Model Context Protocol
- Rust MCP Ecosystem: rust-mcp-stack