Create the MCP Server Pipeline Manually

Build a pipeline that exposes tools for AI agents using Function Generator Snaps and the MCP Server Router.

Familiarity with building pipelines in SnapLogic Designer.
A project for your MCP Server Pipeline and its tool pipelines.
The MCP Server Snap Pack, which provides the MCP Server Router used by every MCP Server Pipeline.
For a Pipeline as Tool, OpenAPI, or APIM Service tool source, the LLM Utilities Snap Pack, which provides the Multi Pipeline, OpenAPI, and APIM Function Generators.
For an MCP Client tool source, the MCP Client Snap Pack, which provides the MCP Function Generator and MCP Invoke Snaps.

Overview

An MCP Server Pipeline defines the tools that AI agents can discover and invoke. The pipeline must handle two MCP protocol methods:

tools/list: Returns the list of available tools with their schemas
tools/call: Executes the requested tool and returns results

SnapLogic supports four tool source types that you can use individually or combine in a single MCP Server:

Pipeline as Tool: Expose existing SnapLogic pipelines as MCP tools
OpenAPI: Convert OpenAPI specifications into MCP tools
APIM Service: Expose APIM-managed APIs as MCP tools
MCP Client: Re-expose tools from external MCP Servers

Tip: The quickest way to create an MCP Server Pipeline is with the MCP Server Pipeline Builder. You can also build the pipeline manually for more advanced configurations.

Pipeline Architecture

All MCP Server Pipelines follow the same core architecture pattern:

Function Generator - Defines available tools and their schemas
MCP Server Router - Routes requests to list or call handlers
Pipeline Execute - Executes the tool logic
Mapper - Transforms output (removes internal metadata)
Union - Merges the list and call response streams

Pipeline as Tool

Use the Multi Pipeline Function Generator Snap to expose existing SnapLogic pipelines as MCP tools. Each pipeline becomes an invocable tool.

Tool Pipeline Requirements

Pipelines used as tools must:

Have the Expose this pipeline as a tool toggle enabled, and define tool inputs and a description in the Tool tab of the Edit Pipeline dialog. Tool inputs define the parameters the LLM provides when calling this tool. Refer to Tool tab in Pipeline Properties for details.
Have a defined input and output view

Pipeline Structure

MCP Server Pipeline structure: Function Generator, MCP Server Router, Pipeline Execute, Mapper, and Union Snaps connected in sequence

Multi Pipeline Function Generator Settings

Pipeline Paths: List of pipeline paths to expose as tools (relative to the project). Refer to Tool Pipelines for a downloadable example.
Strict Mode: When enabled, requires exact parameter matches

Pipeline Execute Settings

Pipeline: Set to expression $sl_tool_metadata.path to dynamically execute the requested tool pipeline
Executable during suggest: Enable for real-time tool discovery

Pipeline Execute Snap configured with the pipeline field set to the sl_tool_metadata.path expression

OpenAPI Tool

Use the OpenAPI Function Generator Snap to convert OpenAPI (Swagger) specifications into MCP tools. Each API operation becomes a separate tool.

OpenAPI Function Generator Settings

Input Type: Choose between Text editor, File, or URL
OpenAPI Spec: Paste or reference your OpenAPI/Swagger specification (JSON or YAML)
Base URL: The base URL for API calls (overrides the spec's server URL)
Tool Path: Path to the tool pipeline that executes the API calls
Preferred Content Type: Default content type for requests (e.g., application/json)
Account: Optional account for authenticated API calls

Tool Pipeline

Create a separate pipeline (tagged with tool) that handles the actual API execution. This pipeline receives the operation details and parameters, executes the HTTP request, and returns the response. Refer to Tool Pipelines for a downloadable example.

APIM Service Tool

Use the APIM Function Generator Snap to expose APIs managed by SnapLogic API Management as MCP tools.

APIM Function Generator Settings

Project Path: The SnapLogic project containing the APIM service (e.g., projects/MyProject)
Service Name: The name of the APIM service
Service Version: The version of the APIM service
Base URL: The APIM gateway URL for the service
Tool Path: Path to the tool pipeline that executes API calls. Refer to Tool Pipelines for a downloadable example.
Filter Type: Choose to use all paths or filter by specific paths/tags
Preferred Content Type: Default content type for requests

MCP Client Tool

Use the MCP Function Generator Snap to re-expose tools from external MCP Servers. This enables MCP Server composition, allowing you to aggregate tools from multiple sources.

MCP Function Generator Settings

Account: MCP Streamable HTTP Account configured to connect to the external MCP Server
Tool Path: Path to the tool pipeline that invokes the external MCP tools. Refer to Tool Pipelines for more on this pattern.
Expose Tools: Enable to expose the external server's tools
Expose Resources: Enable to expose the external server's resources (if supported)

Tool Pipeline Requirements

The tool pipeline uses the MCP Invoke Snap to call tools on the external MCP Server:

Account: The same MCP Streamable HTTP Account
Operation: Set to $sl_tool_metadata.operation
Tool Name: Set to $sl_tool_name
Parameters: Filter out internal metadata fields

Combining Multiple Tool Types

You can combine multiple Function Generators in a single MCP Server Pipeline to expose tools from different sources. Link the different tool types in a series, using the appropriate Function Generator Snap for each source type. Don't link them in parallel using only the Multi Pipeline Function Generator Snap.

Chain the Function Generators together so each one passes its output to the next. The combined tool list flows to the MCP Server Router, which handles both listing all tools and routing tool calls to the appropriate execution path.

Build the pipeline manually

In Designer, create a new pipeline.
Add a Function Generator Snap based on your tool source type.
- Multi Pipeline Function Generator for pipeline-based tools
- OpenAPI Function Generator for OpenAPI/Swagger specs
- APIM Function Generator for APIM services
- MCP Function Generator for external MCP Server tools
Configure the Function Generator with your tool definitions or source references.
Add an MCP Server Router Snap and connect the Function Generator output to its input.

Configure the Request property to $original to pass the original MCP request.

Note: Adding the MCP Server Router Snap automatically tags the pipeline as an MCP server. No manual tagging is required.
Connect the Router's Tool list view output directly to a Union Snap.

This path handles tools/list requests.
Connect the Router's Tool call view output to a Pipeline Execute Snap.
Configure Pipeline Execute:
- Pipeline: $sl_tool_metadata.path (expression)
- Executable during suggest: Enabled
Add a Mapper Snap after Pipeline Execute to remove internal metadata.
Configure the Mapper transformation:
```
$.filter((value, key) => !key.startsWith("original"))
```
This removes the original request data from the response.
Connect the Mapper output to the Union Snap's second input.
Save and validate the pipeline.

Example Pipelines

Download these example pipelines to use as templates:

MCP Server - Pipeline as Tool: Exposes a weather forecast Pipeline as an MCP tool
MCP Server - OpenAPI: Converts a Petstore OpenAPI spec to MCP tools
MCP Server - APIM: Exposes an APIM Petstore service as MCP tools
MCP Server - MCP Client: Re-exposes tools from an external MCP Server
MCP Server - All Tool Types: Combines Pipeline, OpenAPI, and APIM tools in one server

Tool Pipelines

An MCP Server Pipeline usually doesn't do the requested work itself — it calls a separate tool pipeline to do it. The Multi Pipeline Function Generator's Pipeline Paths setting and the OpenAPI and APIM Function Generators' Tool Path setting each point to a tool pipeline like this.

The following downloads are minimal test tool pipelines. Their only job is to confirm that an adjacent MCP Server Pipeline example above is wired correctly end to end — that a tools/call request reaches the tool pipeline through Pipeline Execute and a response makes it back through the Union. ( tools/list requests don't reach the tool pipeline at all — the Router sends its tool-list output directly to the Union.) Neither tool pipeline is a complete, working implementation of the API it's named after. You can use these tool pipelines to test their correspondingly named MCP Server Pipeline examples.

TOOL_weather_forecast.slp: Verifies the MCP Server - Pipeline as Tool example above. Its base configuration calls a public weather API with a fixed set of parameters — treat it as a starting point, not a fully-built weather integration.
TOOL_OpenAPI_PetStore.slp: Verifies the MCP Server - OpenAPI example above. It sends one JSON-body request with no headers to confirm the pipeline wiring works; it doesn't implement the Petstore API. Implementing Petstore's operations against its OpenAPI spec is up to you — at minimum you'll need to:
- Route requests by content type. The Snap's Entity Type setting is fixed to Raw (JSON), so operations that require a multipart/form-data body (for example, uploadFile) or an application/x-www-form-urlencoded body (for example, updatePetWithForm) need their own handling.
- Forward header-based parameters. The Snap's Header table is empty, so header inputs such as deletePet's api_key are accepted as tool input but not currently sent to Petstore.

Note: The MCP Server - APIM example's APIM Function Generator has its Tool Path set to TOOL_OpenAPI_PetStore as well, so it uses the same test tool pipeline to verify its wiring — it doesn't implement APIM's Petstore service either.

After creating your MCP Server Pipeline, proceed to Register MCP Server to create an MCP Server asset.