Android Preference Editor MCP Server

Instructions

Implementation Reference

• src/tools/prefs.ts:91-124 (handler)

  The handler function that executes the 'add_preference' tool logic: validates input, constructs Preference object using parseDataType, calls imported addPreference, returns success/error text response.

  async (input: z.infer<typeof AddPrefSchema>) => {
    try {
      validate(input, AddPrefSchema);
  
      const { name, value, type, ...connection } = input;
  
      const pref: Preference = {
        key: name,
        value,
        type: parseDataType(type),
      };
  
      await addPreference(pref, connection);
  
      return {
        content: [
          {
            type: "text",
            text: `Preference added`,
          },
        ],
      };
    } catch (error) {
      return {
        isError: true,
        content: [
          {
            type: "text",
            text: error instanceof Error ? error.message : "Unknown error",
          },
        ],
      };
    }
  }

• src/tools/prefs.ts:87-125 (registration)

  Registration of the 'add_preference' MCP tool using server.tool() with name, description, AddPrefSchema.shape, and inline handler.

  server.tool(
    "add_preference",
    "Adds a new preference given the name, value and type.",
    AddPrefSchema.shape,
    async (input: z.infer<typeof AddPrefSchema>) => {
      try {
        validate(input, AddPrefSchema);
  
        const { name, value, type, ...connection } = input;
  
        const pref: Preference = {
          key: name,
          value,
          type: parseDataType(type),
        };
  
        await addPreference(pref, connection);
  
        return {
          content: [
            {
              type: "text",
              text: `Preference added`,
            },
          ],
        };
      } catch (error) {
        return {
          isError: true,
          content: [
            {
              type: "text",
              text: error instanceof Error ? error.message : "Unknown error",
            },
          ],
        };
      }
    }
  );

• src/schema.ts:15-35 (schema)

  Zod schema definitions for preference tools, including AddPrefSchema = TypedPrefSchema.merge(FileSchema) used for input validation of 'add_preference'.

  export const NameSchema = z.object({
    name: z.string().describe("The name/key of the user preference"),
  });
  
  export const PrefSchema = NameSchema.extend({
    value: z.string().describe("The value of user preference"),
  });
  
  export const TypedPrefSchema = PrefSchema.extend({
    type: z
      .string()
      .describe(
        "The type of the preference value: integer, boolean, float, double, long or string"
      ),
  });
  
  export const AddPrefSchema = TypedPrefSchema.merge(FileSchema);
  
  export const EditPrefSchema = PrefSchema.merge(FileSchema);
  
  export const DeletePrefSchema = NameSchema.merge(FileSchema);

• src/index.ts:21-22 (registration)

  Invocation of configurePreferenceTools which registers the 'add_preference' tool (and others) on the MCP server.

  configurePreferenceTools(server);
  configureCommonTools(server);