Salesforce MCP Server

Instructions

Implementation Reference

• src/tools/manageField.ts:134-283 (handler)

  The main handler function that executes the salesforce_manage_field tool logic. It handles 'create' and 'update' operations on Salesforce custom fields using the Salesforce metadata API via conn.metadata.create/update.
  export async function handleManageField(conn: any, args: ManageFieldArgs) { const { operation, objectName, fieldName, type, ...fieldProps } = args; try { if (operation === 'create') { if (!type) { throw new Error('Field type is required for field creation'); } // Prepare base metadata for the new field const metadata: FieldMetadataInfo = { fullName: `${objectName}.${fieldName}__c`, label: fieldProps.label || fieldName, type, ...(fieldProps.required && { required: fieldProps.required }), ...(fieldProps.unique && { unique: fieldProps.unique }), ...(fieldProps.externalId && { externalId: fieldProps.externalId }), ...(fieldProps.description && { description: fieldProps.description }) }; // Add type-specific properties switch (type) { case 'MasterDetail': case 'Lookup': if (fieldProps.referenceTo) { metadata.referenceTo = fieldProps.referenceTo; metadata.relationshipName = fieldProps.relationshipName; metadata.relationshipLabel = fieldProps.relationshipLabel || fieldProps.relationshipName; if (type === 'Lookup' && fieldProps.deleteConstraint) { metadata.deleteConstraint = fieldProps.deleteConstraint; } } break; case 'TextArea': metadata.type = 'LongTextArea'; metadata.length = fieldProps.length || 32768; metadata.visibleLines = 3; break; case 'Text': if (fieldProps.length) { metadata.length = fieldProps.length; } break; case 'Number': if (fieldProps.precision) { metadata.precision = fieldProps.precision; metadata.scale = fieldProps.scale || 0; } break; case 'Picklist': case 'MultiselectPicklist': if (fieldProps.picklistValues) { metadata.valueSet = { valueSetDefinition: { sorted: true, value: fieldProps.picklistValues.map(val => ({ fullName: val.label, default: val.isDefault || false, label: val.label })) } }; } break; } // Create the field const result = await conn.metadata.create('CustomField', metadata); if (result && (Array.isArray(result) ? result[0].success : result.success)) { return { content: [{ type: "text", text: `Successfully created custom field ${fieldName}__c on ${objectName}` }], isError: false, }; } } else { // For update, first get existing metadata const existingMetadata = await conn.metadata.read('CustomField', [`${objectName}.${fieldName}__c`]); const currentMetadata = Array.isArray(existingMetadata) ? existingMetadata[0] : existingMetadata; if (!currentMetadata) { throw new Error(`Field ${fieldName}__c not found on object ${objectName}`); } // Prepare update metadata const metadata: FieldMetadataInfo = { ...currentMetadata, ...(fieldProps.label && { label: fieldProps.label }), ...(fieldProps.required !== undefined && { required: fieldProps.required }), ...(fieldProps.unique !== undefined && { unique: fieldProps.unique }), ...(fieldProps.externalId !== undefined && { externalId: fieldProps.externalId }), ...(fieldProps.description !== undefined && { description: fieldProps.description }), ...(fieldProps.length && { length: fieldProps.length }), ...(fieldProps.precision && { precision: fieldProps.precision, scale: fieldProps.scale || 0 }) }; // Special handling for picklist values if provided if (fieldProps.picklistValues && (currentMetadata.type === 'Picklist' || currentMetadata.type === 'MultiselectPicklist')) { metadata.valueSet = { valueSetDefinition: { sorted: true, value: fieldProps.picklistValues.map(val => ({ fullName: val.label, default: val.isDefault || false, label: val.label })) } }; } // Update the field const result = await conn.metadata.update('CustomField', metadata); if (result && (Array.isArray(result) ? result[0].success : result.success)) { return { content: [{ type: "text", text: `Successfully updated custom field ${fieldName}__c on ${objectName}` }], isError: false, }; } } return { content: [{ type: "text", text: `Failed to ${operation} custom field ${fieldName}__c` }], isError: true, }; } catch (error) { return { content: [{ type: "text", text: `Error ${operation === 'create' ? 'creating' : 'updating'} custom field: ${error instanceof Error ? error.message : String(error)}` }], isError: true, }; } }
• src/tools/manageField.ts:4-112 (schema)

  The Tool definition including name, description, and detailed inputSchema for validating parameters like operation, objectName, fieldName, type, picklistValues, etc.
  export const MANAGE_FIELD: Tool = { name: "salesforce_manage_field", description: `Create new custom fields or modify existing fields on any Salesforce object: - Field Types: Text, Number, Date, Lookup, Master-Detail, Picklist etc. - Properties: Required, Unique, External ID, Length, Scale etc. - Relationships: Create lookups and master-detail relationships Examples: Add Rating__c picklist to Account, Create Account lookup on Custom Object Note: Changes affect metadata and require proper permissions`, inputSchema: { type: "object", properties: { operation: { type: "string", enum: ["create", "update"], description: "Whether to create new field or update existing" }, objectName: { type: "string", description: "API name of the object to add/modify the field" }, fieldName: { type: "string", description: "API name for the field (without __c suffix)" }, label: { type: "string", description: "Label for the field", optional: true }, type: { type: "string", enum: ["Checkbox", "Currency", "Date", "DateTime", "Email", "Number", "Percent", "Phone", "Picklist", "MultiselectPicklist", "Text", "TextArea", "LongTextArea", "Html", "Url", "Lookup", "MasterDetail"], description: "Field type (required for create)", optional: true }, required: { type: "boolean", description: "Whether the field is required", optional: true }, unique: { type: "boolean", description: "Whether the field value must be unique", optional: true }, externalId: { type: "boolean", description: "Whether the field is an external ID", optional: true }, length: { type: "number", description: "Length for text fields", optional: true }, precision: { type: "number", description: "Precision for numeric fields", optional: true }, scale: { type: "number", description: "Scale for numeric fields", optional: true }, referenceTo: { type: "string", description: "API name of the object to reference (for Lookup/MasterDetail)", optional: true }, relationshipLabel: { type: "string", description: "Label for the relationship (for Lookup/MasterDetail)", optional: true }, relationshipName: { type: "string", description: "API name for the relationship (for Lookup/MasterDetail)", optional: true }, deleteConstraint: { type: "string", enum: ["Cascade", "Restrict", "SetNull"], description: "Delete constraint for Lookup fields", optional: true }, picklistValues: { type: "array", items: { type: "object", properties: { label: { type: "string" }, isDefault: { type: "boolean", optional: true } } }, description: "Values for Picklist/MultiselectPicklist fields", optional: true }, description: { type: "string", description: "Description of the field", optional: true } }, required: ["operation", "objectName", "fieldName"] } };
• src/index.ts:36-47 (registration)

  Registration of the tool in the MCP server's listTools handler, exporting MANAGE_FIELD for discovery.
  server.setRequestHandler(ListToolsRequestSchema, async () => ({ tools: [ SEARCH_OBJECTS, DESCRIBE_OBJECT, QUERY_RECORDS, DML_RECORDS, MANAGE_OBJECT, MANAGE_FIELD, SEARCH_ALL, UPLOAD_REPORT_XML // Add new tool to the list ], }));
• src/index.ts:118-143 (registration)

  The switch case in the callTool handler that validates input arguments and invokes the handleManageField function.
  case "salesforce_manage_field": { const fieldArgs = args as Record<string, unknown>; if (!fieldArgs.operation || !fieldArgs.objectName || !fieldArgs.fieldName) { throw new Error('operation, objectName, and fieldName are required for field management'); } const validatedArgs: ManageFieldArgs = { operation: fieldArgs.operation as 'create' | 'update', objectName: fieldArgs.objectName as string, fieldName: fieldArgs.fieldName as string, label: fieldArgs.label as string | undefined, type: fieldArgs.type as string | undefined, required: fieldArgs.required as boolean | undefined, unique: fieldArgs.unique as boolean | undefined, externalId: fieldArgs.externalId as boolean | undefined, length: fieldArgs.length as number | undefined, precision: fieldArgs.precision as number | undefined, scale: fieldArgs.scale as number | undefined, referenceTo: fieldArgs.referenceTo as string | undefined, relationshipLabel: fieldArgs.relationshipLabel as string | undefined, relationshipName: fieldArgs.relationshipName as string | undefined, deleteConstraint: fieldArgs.deleteConstraint as 'Cascade' | 'Restrict' | 'SetNull' | undefined, picklistValues: fieldArgs.picklistValues as Array<{ label: string; isDefault?: boolean }> | undefined, description: fieldArgs.description as string | undefined }; return await handleManageField(conn, validatedArgs); }