Salesforce Hosted Custom Server

A reference SFDX project demonstrating every supported pattern for building a Salesforce-hosted custom MCP (Model Context Protocol) server. Each McpServerDefinition shows a different way to expose Salesforce functionality — Apex classes, Flows, Named Queries, and Prompt Templates — as tools that any MCP-compatible client (Claude Desktop, OpenAI, Cursor, etc.) can discover and call.

Blog series: Salesforce Diaries by Sanket

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What is a Salesforce Hosted MCP Server?

Salesforce lets you publish a standard MCP endpoint directly from your org — no middleware, no Lambda, no Node server. You define what tools are exposed through McpServerDefinition metadata, and Salesforce handles the authentication, schema generation, and HTTP transport. An external AI agent connects to https://<your-org>.my.salesforce.com/services/mcp/v1/<serverName> using OAuth and gets a live, permissioned connection to your data.

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Project Structure

force-app/main/default/
├── mcpServerDefinitions/          # 14 MCP server definitions (one per pattern)
├── externalServiceRegistrations/  # OpenAPI registrations for each Apex endpoint
├── flows/
│   └── Get_Account_By_Name.flow-meta.xml
├── classes/                       # 7 Apex classes backing the MCP tools
└── genAiPromptTemplates/          # 4 Prompt Builder templates exposed as MCP prompts
sfdx-project.json

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MCP Server Definitions

Each definition registers one MCP server in your org and declares which tools and prompts it exposes.

1. FlowAsMcpService — Flow as MCP Tool

Exposes the Get_Account_By_Name AutoLaunchedFlow as a tool.
Pattern: fa:flow-<FlowApiName> (Flow via API Catalog)

Tool → Get_Account_By_Name

2. FlowMCP — Flow MCP (variant)

A second server exposing the same Get_Account_By_Name flow, demonstrating that multiple servers can surface the same underlying action.
Pattern: fa:flow-<FlowApiName>

3. InvocableApex — Invocable Apex + Prompt Templates

Combines an @InvocableMethod tool with three Prompt Builder prompts in one server.
Pattern: aa:apex-<ClassName> + promptTemplateName

Tool   → CreateCaseAction
Prompt → Draft_IT_Troubleshooting
Prompt → Get_Event_Info
Prompt → Case_Research_from_Web

4. AuraEnabledApexMCP — @AuraEnabled Method

Exposes the getHighValueOpportunities method from OpportunityMcpService (annotated @AuraEnabled).
Pattern: ae:<ClassName>

Tool → getHighValueOpportunities (OpportunityMcpService)

5. AuraEnbaledClassMcp — @AuraEnabled (alternate class)

Same tool pattern as above but backed by OpportunityMcpServiceAuraEnbaled.
Pattern: ae:<ClassName>

Tool → getHighValueOpportunities (OpportunityMcpServiceAuraEnbaled)

6. PublicInvocableApexMCP — @AuraEnabled for Account Analytics

Exposes AccountAnalytics.invoke — a multi-mode analytics tool that runs aggregations over Account records.
Pattern: ae:<ClassName>

Tool → invoke (AccountAnalytics)

7. AIAgentMcpServer — Talk to an Agentforce Agent

Lets an MCP client send a natural-language message to an Agentforce agent and get its reply. Supports multi-turn sessions via sessionId.
Pattern: ae:<ClassName>

Tool → askAgent (InvokeAgentAction)

8. CaseCreationInvocableMcpService — Create Cases via Invocable

Exposes CreateCaseAction as an MCP tool so external agents can open support cases directly.
Pattern: aa:apex-<ClassName>

Tool → CreateCaseAction

9. NamedQueryMcpService — Named Query

Exposes a Named Query (GetOpportunitiesByAmount) defined in the org as a zero-code MCP tool.
Pattern: nq:<QueryApiName>

Tool → GetOpportunitiesByAmount

10. PromptTemplateMcpServer — Named Query + Prompt Template

Mixes a Named Query tool with a Prompt Builder prompt in one server.
Pattern: nq:<QueryApiName> + promptTemplateName

Tool   → GetOpportunitiesByAmount
Prompt → Research_on_Case_subject

11. RestResourceApexMCP — @RestResource Apex

Exposes MyCustomAPI — a @RestResource-annotated class — as an MCP tool.
Pattern: ar:<ClassName>

Tool → doGet (MyCustomAPI)

12. PromptMcpServer — Prompt-Only Server

A server that exposes only a Prompt Builder template, with no tool.
Pattern: promptTemplateName

Prompt → Case_Research_from_Web

13. AgentforceMCP — Agentforce Agent Shell

Skeleton server demonstrating how to declare an Agentforce-connected MCP server.

14. RestAPIMCP — REST API Shell

Skeleton server for REST-based MCP tool patterns.

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Apex Classes

Class	Annotation	What it does
OpportunityMcpService	@AuraEnabled	Returns Opportunities with Amount > threshold (default $50k), ordered largest first. Enforces sharing and FLS via WITH USER_MODE.
OpportunityMcpServiceAuraEnbaled	@AuraEnabled	Variant of the above, demonstrating the same pattern in a separate class.
AccountAnalytics	@InvocableMethod	Runs one of four aggregation modes over Account: top_revenue, by_industry, recent, or health_summary. Returns a human-readable summary string.
CreateCaseAction	@InvocableMethod	Creates a Salesforce Case from a subject line. Bulk-safe; re-queries to return the auto-assigned Case Number.
InvokeAgentAction	@InvocableMethod	Sends a natural-language message to any active Agentforce agent via generateAiAgentResponse. Returns the agent's reply and a sessionId for multi-turn conversations. Default agent: Case_CRUD_Agent.
MyCustomAPI	@RestResource	GET /services/apexrest/MyCustomAPI/ — returns Opportunities above a configurable minAmount threshold. Used by RestResourceApexMCP.
PromptTemplateMcpService	@AuraEnabled	Runs a named Prompt Builder template against a record using ConnectApi.EinsteinLLM.generateMessagesForPromptTemplate. Returns the generated text.

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Flow

Get_Account_By_Name

Type: AutoLaunchedFlow
Input: AccountName (String)
Output: AccountDetails (Account SObject)

Queries the first Account whose Name equals the input string and returns the full record. Used by FlowAsMcpService and FlowMCP.

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Prompt Templates (genAiPromptTemplates)

These Prompt Builder templates are registered on MCP servers as prompts — the MCP equivalent of a reusable, parameterised instruction that a client can invoke by name.

Template	Referenced by
Draft_IT_Troubleshooting	InvocableApex
Get_Event_Info	InvocableApex
Case_Research_from_Web	InvocableApex, PromptMcpServer
Research_on_Case_subject	PromptTemplateMcpServer

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External Service Registrations

OpenAPI-based registrations that describe the shape of each Apex endpoint so Salesforce can generate the tool schemas for the MCP catalog.

Registration	Apex class
AccountAnalytics	AccountAnalytics
GetCaseByCaseNumber	Case lookup endpoint
GetOpportunitiesByAmount	Named Query
InvokeAgentAction	InvokeAgentAction
MyCustomAPI	MyCustomAPI
OpportunityMcpService	OpportunityMcpService
OpportunityMcpServiceAuraEnbaled	OpportunityMcpServiceAuraEnbaled
PromptTemplateMcpService	PromptTemplateMcpService

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Deploy

Prerequisites

• Salesforce CLI (sf) v2+
• API version 66.0 org (Summer '25+)
• "Salesforce Hosted MCP Servers" feature enabled in your org

Deploy all metadata

sf project deploy start --source-dir force-app

Deploy a specific server only

sf project deploy start --metadata McpServerDefinition:FlowAsMcpService

Connect a client (example: Claude Desktop)

Add this to your claude_desktop_config.json:

{
  "mcpServers": {
    "salesforce-flow": {
      "url": "https://<your-org>.my.salesforce.com/services/mcp/v1/FlowAsMcpService",
      "transport": "http",
      "headers": {
        "Authorization": "Bearer <access_token>"
      }
    }
  }
}

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References

• Salesforce Hosted MCP Servers — Developer Guide
• AuraEnabled MCP pattern
• Model Context Protocol spec