MCP Proxy

Field reference for the MCP Proxy configuration, which reads an OpenAPI specification and generates one MCP tool per REST endpoint.

An MCP Proxy reads an OpenAPI 3.0 specification and generates one MCP tool per REST endpoint, making any conventional HTTP API accessible to MCP-compatible agents without modification.

Overview

An MCP proxy is a named component independent of any surface. Once created, it can be targeted by any number of MCP surfaces using the proxy:// scheme. Attaching a proxy to a surface adds authentication, OPA policies, observability, and credential injection on top of the generated tools. Without a surface, agents can call tools directly at the proxy route.

The proxy route is formed from the configured Listen Address, Path Prefix, and Custom Endpoint Path.

Fields

FieldTypeRequiredDefaultDescription
NamestringYes—Human-readable label shown in the dashboard proxy list and selector dropdowns. Must be unique within the gateway.
DescriptionstringNoNoneFree-text notes for other administrators. Not used in routing.
Listen AddressstringYes—The host and port the proxy listener binds to. Selected from the gateway’s configured listener addresses.
Path PrefixstringYes—URL prefix for this proxy’s route. Combined with Custom Endpoint Path to form the full proxy route.
Custom Endpoint PathstringYes—Final path segment that uniquely identifies this proxy’s route within the selected prefix.
Base URLURLYes—Base address of the upstream REST API. Tool calls are forwarded to this URL with the endpoint path appended.
OpenAPI Specificationstring (YAML)Yes—OpenAPI 3.0 specification in YAML format. The gateway parses this on save and generates one MCP tool per endpoint. No manual tool mapping is required.

Proxy route

The proxy route is the full address at which MCP clients can reach the proxy directly, before any surface is involved:

    https://<listen-address><path-prefix><custom-endpoint-path>

The dashboard shows a live MCP Proxy Route preview during the creation wizard.

Tool generation

The gateway parses the OpenAPI specification when the proxy is saved and creates one MCP tool per endpoint. Tool names are derived from the endpoint’s operationId when present, or from the HTTP method and path pattern otherwise.

Tool definitions update immediately when the OpenAPI specification is changed and saved. MCP surfaces targeting the proxy reflect the updated tool list without reconfiguration.

Targeting a proxy from a surface

In the canvas editor, open the Managed Agent node, set Endpoint Type to via MCP Proxy, and select the proxy from the MCP Proxy dropdown. The dashboard sets the endpoint automatically.

See Target for full Target Endpoint URL documentation, including all supported endpoint schemes.

Sandbox

The proxy editor includes a built-in sandbox for testing tool calls directly from the dashboard without connecting an external client. Select Connect & List Tools to issue a tools/list call, then select a tool to run it with custom input parameters.