mercury_get_customer

Instructions

Implementation Reference

• src/tools/customers.ts:50-70 (handler)

  Handler function that retrieves a specific Accounts Receivable customer by ID. Calls Mercury API GET /ar/customers/{customerId} and returns the result.

  defineTool(
    server,
    "mercury_get_customer",
    [
      "Retrieve a specific Accounts Receivable customer by ID.",
      "",
      "USE WHEN: fetching the full detail of one customer whose ID is already known. Faster than relisting + filtering when you have the ID.",
      "",
      "DO NOT USE: to enumerate customers (use `mercury_list_customers`). For payment recipients use `mercury_list_recipients` (different surface).",
      "",
      "RETURNS: `{ id, name, email, address, ... }`.",
    ].join("\n"),
    {
      customerId: z.uuid().describe("Customer ID"),
    },
    async ({ customerId }) => {
      const data = await client.get(`/ar/customers/${customerId}`);
      return textResult(data);
    },
    { title: "Get Customer", readOnlyHint: true, openWorldHint: true },
  );

• src/tools/customers.ts:62-64 (schema)

  Input schema for mercury_get_customer: requires a single 'customerId' parameter (UUID) describing the customer to retrieve.

  {
    customerId: z.uuid().describe("Customer ID"),
  },

• src/tools/index.ts:34-34 (registration)

  Registration call that wires mercury_get_customer (along with other customer tools) onto the MCP server via registerCustomerTools.

  registerCustomerTools(server, client);

• src/tools/customers.ts:18-148 (registration)

  Registration function that registers all customer tools (including mercury_get_customer) on the MCP server using defineTool.

  export function registerCustomerTools(server: McpServer, client: MercuryClient): void {
    defineTool(
      server,
      "mercury_list_customers",
      [
        "List Accounts Receivable customers, with cursor-based pagination.",
        "",
        "USE WHEN: enumerating AR customers before creating an invoice (need a `customerId` for `mercury_create_invoice`), or for a customer-level audit. Use `startAfter` / `endBefore` for paging beyond the limit.",
        "",
        "DO NOT USE: for payment recipients (`mercury_list_recipients` is the bank-payment counterparty list, distinct from AR customers). For one customer whose ID is known, prefer `mercury_get_customer`.",
        "",
        "RETURNS: `{ customers: [{ id, name, email, address, ... }] }`.",
      ].join("\n"),
      {
        limit: z.number().int().min(1).max(1000).optional().describe("Max results (1-1000)"),
        order: z.enum(["asc", "desc"]).optional(),
        startAfter: z.uuid().optional().describe("Pagination cursor (forward)"),
        endBefore: z.uuid().optional().describe("Pagination cursor (reverse)"),
      },
      async (args) => {
        const query: Record<string, string | number | undefined> = {
          limit: args.limit,
          order: args.order,
          start_after: args.startAfter,
          end_before: args.endBefore,
        };
        const data = await client.get("/ar/customers", query);
        return textResult(data);
      },
      { title: "List Customers", readOnlyHint: true, openWorldHint: true },
    );
  
    defineTool(
      server,
      "mercury_get_customer",
      [
        "Retrieve a specific Accounts Receivable customer by ID.",
        "",
        "USE WHEN: fetching the full detail of one customer whose ID is already known. Faster than relisting + filtering when you have the ID.",
        "",
        "DO NOT USE: to enumerate customers (use `mercury_list_customers`). For payment recipients use `mercury_list_recipients` (different surface).",
        "",
        "RETURNS: `{ id, name, email, address, ... }`.",
      ].join("\n"),
      {
        customerId: z.uuid().describe("Customer ID"),
      },
      async ({ customerId }) => {
        const data = await client.get(`/ar/customers/${customerId}`);
        return textResult(data);
      },
      { title: "Get Customer", readOnlyHint: true, openWorldHint: true },
    );
  
    defineTool(
      server,
      "mercury_create_customer",
      [
        "Create a new Accounts Receivable customer (a billable entity you will later invoice).",
        "",
        "USE WHEN: onboarding a new customer before issuing them an invoice. The returned `id` is what `mercury_create_invoice` expects as `customerId`.",
        "",
        "DO NOT USE: for payment recipients (use `mercury_add_recipient` — different surface, used for outbound bank transfers, not invoicing).",
        "",
        "SIDE EFFECTS: writes a new customer to your Mercury workspace. Persistent. NOT idempotent at the API level — calling twice with the same payload creates two customers; check `mercury_list_customers` for existing entries before creating to avoid duplicates.",
        "",
        "RETURNS: `{ id, name, email, address, ... }` — keep `id` for the invoicing tools.",
      ].join("\n"),
      {
        name: z.string().describe("Customer name"),
        email: z.email().describe("Customer email"),
        address: addressSchema.optional(),
      },
      async (args) => {
        const data = await client.post("/ar/customers", args);
        return textResult(data);
      },
      { title: "Create Customer", destructiveHint: false, openWorldHint: true },
    );
  
    defineTool(
      server,
      "mercury_update_customer",
      [
        "Update an existing Accounts Receivable customer. Pass only the fields you want to change.",
        "",
        "USE WHEN: amending a customer's contact details (name, email, billing address) after creation. Existing invoices are not retroactively modified.",
        "",
        "DO NOT USE: to delete a customer (use `mercury_delete_customer`). To change the customer of an existing invoice, cancel + recreate the invoice.",
        "",
        "SIDE EFFECTS: writes the new customer record to Mercury. Persistent. Only the fields you pass are changed — omitted fields keep their current value.",
        "",
        "RETURNS: `{ id, name, email, address, ... }` — the updated customer.",
      ].join("\n"),
      {
        customerId: z.uuid().describe("Customer ID"),
        name: z.string().optional(),
        email: z.email().optional(),
        address: addressSchema.optional(),
      },
      async ({ customerId, ...body }) => {
        const data = await client.patch(`/ar/customers/${customerId}`, body);
        return textResult(data);
      },
      { title: "Update Customer", destructiveHint: false, openWorldHint: true },
    );
  
    defineTool(
      server,
      "mercury_delete_customer",
      [
        "Permanently delete an Accounts Receivable customer. **DESTRUCTIVE.**",
        "",
        "USE WHEN: removing a customer that was created by mistake, or that the user explicitly wants to purge. ALWAYS confirm with the user before calling — there is no undo.",
        "",
        "DO NOT USE: when the customer has invoices in `paid` / `outstanding` status — Mercury rejects deletion in those cases and returns a 409. Cancel outstanding invoices first via `mercury_cancel_invoice`.",
        "",
        "SIDE EFFECTS: **permanent deletion** on Mercury's side. The customer disappears from the AR list. Past invoices' `customerId` may dangle (Mercury does not cascade-delete invoices). NOT recoverable from API. ALWAYS confirm with the user.",
        "",
        "RETURNS: confirmation payload from Mercury (`{ deleted: true, ... }` or similar).",
      ].join("\n"),
      {
        customerId: z.uuid().describe("Customer ID"),
      },
      async ({ customerId }) => {
        const data = await client.delete(`/ar/customers/${customerId}`);
        return textResult(data);
      },
      { title: "Delete Customer", destructiveHint: true, openWorldHint: true },
    );
  }