Config Reference

mcpr looks for mcpr.toml in the current directory, then parent directories.

All fields

Top-level

Field	Type	Default	Description
mcp	string	required	Upstream MCP server URL
widgets	string	—	Widget source: URL to proxy, or local path for static serving
port	number	3000	Local proxy port
no_tunnel	boolean	false	Disable tunnel, direct HTTP mode
no_tui	boolean	false	Disable TUI dashboard (for Docker/CI)
drain_timeout	number	30	Graceful shutdown timeout in seconds
log_format	string	json	Stderr log format: json or pretty
admin_bind	string	127.0.0.1:9901	Admin API bind address (set to none to disable)
tunnel_token	string	auto-generated	Tunnel authentication token
relay_url	string	tunnel.mcpr.app	Custom relay server URL
csp	string[]	—	Extra CSP domains to include in injected headers
csp_mode	string	extend	CSP mode: extend adds to auto-detected headers, override replaces them

[cloud] section

Field	Type	Default	Description
token	string	—	Cloud authentication token from cloud.mcpr.app
server	string	—	Server slug to identify this proxy in your cloud project
endpoint	string	https://api.mcpr.app	Custom ingest endpoint URL
batch_size	number	—	Events per batch before flushing
flush_interval_ms	number	—	Flush interval in milliseconds

Auto-generated fields

On first run, mcpr generates a tunnel_token and appends it to mcpr.toml. This keeps your tunnel URL stable across restarts. You don’t need to set it manually.

Examples

Minimal

mcp = "http://localhost:9000"

Development with widgets

mcp = "http://localhost:9000"
widgets = "http://localhost:4444"

Production (no tunnel)

mcp = "http://localhost:9000"
no_tunnel = true
port = 8080

Static widgets from disk

mcp = "http://localhost:9000"
widgets = "./widgets/dist"

With cloud sync

mcp = "http://localhost:9000"
widgets = "http://localhost:4444"

[cloud]
token = "mcpr_xxxxxxxx"
server = "my-proxy"

Full-featured

mcp = "http://localhost:9000"
widgets = "http://localhost:4444"
port = 3000
# no_tunnel = true   # uncomment for production (disables tunnel)
tunnel_token = "tok_abc123..."
csp = ["cdn.example.com", "api.example.com"]
csp_mode = "extend"

[cloud]
token = "mcpr_xxxxxxxx"
server = "my-proxy"

Custom relay

mcp = "http://localhost:9000"
relay_url = "https://relay.yourdomain.com"

Local development (no tunnel)

mcp = "http://localhost:9000"
no_tunnel = true
port = 3000

Config templates

See config_examples/ in the repository for ready-to-use templates.

[logging] section

Field	Type	Default	Description
file	boolean	false	Enable JSONL file logging
dir	string	./logs	Directory for log files
rotation	string	daily	Rotation strategy: daily or size:50MB

Environment variables

Variable	Description
MCPR_RELAY_URL	Custom relay server URL
MCPR_CLOUD_TOKEN	Cloud sync token (from cloud.mcpr.app)
MCPR_AUTH_PROVIDER	Auth provider URL (relay mode)
MCPR_AUTH_PROVIDER_SECRET	Auth provider shared secret (relay mode)
MCPR_NO_TUI	Set to 1 to disable TUI (set by default in Docker image)
MCPR_TUI	Set to 1 to force TUI on

Environment variables override mcpr.toml values but are overridden by CLI flags.