Environment Variables

These variables are used internally by the gateway and shim. You generally do not need to set them manually. They are documented here for debugging and advanced configuration.

Shim variables

Set by the gateway when spawning shim processes, or read by the shim at startup:

Variable	Description
`MCPFW_GATEWAY_URL`	Gateway base URL (used by shim to locate the gateway)
`MCPFW_SERVER_ID`	Server UUID for this shim instance
`MCPFW_SOCKET_PATH`	Unix socket path for gateway communication
`MCPFW_BYPASS`	Set to `true` to enable bypass mode when the gateway is unreachable. The shim connects directly to the upstream server with read-only enforcement.
`MCPFW_TOKEN`	Bearer token for team gateway authentication (Team tier — coming soon)
`MCPFW_ORIG_COMMAND`	Original MCP server command (before rewrite to shim)
`MCPFW_ORIG_ARGS`	Original MCP server arguments (JSON array)
`MCPFW_ORIG_ENV`	Original MCP server environment variables (JSON object)

Legacy variables

These are accepted for backward compatibility:

Variable	Replaced by
`SLUICE_GATEWAY_URL`	`MCPFW_GATEWAY_URL`
`SLUICE_SERVER_ID`	`MCPFW_SERVER_ID`
`SLUICE_BYPASS`	`MCPFW_BYPASS`
`SLUICE_TOKEN`	`MCPFW_TOKEN`
`SLUICE_ORIG_COMMAND`	`MCPFW_ORIG_COMMAND`
`SLUICE_ORIG_ARGS`	`MCPFW_ORIG_ARGS`
`SLUICE_ORIG_ENV`	`MCPFW_ORIG_ENV`

Secret references

Server configurations can reference vault secrets using:

$MCPFW_SECRET:secret_name

The gateway resolves these at runtime, injecting the decrypted value. The legacy prefix $SLUICE_SECRET: is also accepted.