update-body-measurement

Instructions

Implementation Reference

• src/tools/body-measurements.ts:227-247 (handler)

  The tool handler for 'update-body-measurement' - calls hevyClient.updateBodyMeasurement() with the date and measurement payload built from fields.

  server.tool(
  	"update-body-measurement",
  	"Update an existing body measurement entry for a given date. All fields are overwritten — omitted fields are set to null. Returns 404 if no entry exists for the date.",
  	updateBodyMeasurementSchema,
  	withErrorHandling(async (args: UpdateBodyMeasurementParams) => {
  		if (!hevyClient) {
  			throw new Error(
  				"API client not initialized. Please provide HEVY_API_KEY.",
  			);
  		}
  		const { date, ...fields } = args;
  		await hevyClient.updateBodyMeasurement(
  			date,
  			buildMeasurementPayload(fields),
  		);
  
  		return createTextResponse(
  			`Body measurement for ${date} updated successfully.`,
  		);
  	}, "update-body-measurement"),
  );

• src/tools/body-measurements.ts:214-225 (schema)

  Zod schema for the update-body-measurement tool - requires date (YYYY-MM-DD format) and all optional measurement fields from bodyMeasurementFieldsSchema.

  const updateBodyMeasurementSchema = {
  	date: z
  		.string()
  		.regex(/^\d{4}-\d{2}-\d{2}$/, "Date must be in YYYY-MM-DD format")
  		.describe(
  			"The date of the body measurement to update (YYYY-MM-DD). Must already exist — returns 404 otherwise.",
  		),
  	...bodyMeasurementFieldsSchema,
  } as const;
  type UpdateBodyMeasurementParams = InferToolParams<
  	typeof updateBodyMeasurementSchema
  >;

• src/tools/body-measurements.ts:57-95 (helper)

  Helper function that converts camelCase field names to snake_case for the API payload.

  function buildMeasurementPayload(args: {
  	weightKg?: number | null;
  	leanMassKg?: number | null;
  	fatPercent?: number | null;
  	neckCm?: number | null;
  	shoulderCm?: number | null;
  	chestCm?: number | null;
  	leftBicepCm?: number | null;
  	rightBicepCm?: number | null;
  	leftForearmCm?: number | null;
  	rightForearmCm?: number | null;
  	abdomen?: number | null;
  	waist?: number | null;
  	hips?: number | null;
  	leftThigh?: number | null;
  	rightThigh?: number | null;
  	leftCalf?: number | null;
  	rightCalf?: number | null;
  }) {
  	return {
  		weight_kg: args.weightKg ?? null,
  		lean_mass_kg: args.leanMassKg ?? null,
  		fat_percent: args.fatPercent ?? null,
  		neck_cm: args.neckCm ?? null,
  		shoulder_cm: args.shoulderCm ?? null,
  		chest_cm: args.chestCm ?? null,
  		left_bicep_cm: args.leftBicepCm ?? null,
  		right_bicep_cm: args.rightBicepCm ?? null,
  		left_forearm_cm: args.leftForearmCm ?? null,
  		right_forearm_cm: args.rightForearmCm ?? null,
  		abdomen: args.abdomen ?? null,
  		waist: args.waist ?? null,
  		hips: args.hips ?? null,
  		left_thigh: args.leftThigh ?? null,
  		right_thigh: args.rightThigh ?? null,
  		left_calf: args.leftCalf ?? null,
  		right_calf: args.rightCalf ?? null,
  	};
  }

• src/tools/body-measurements.ts:23-55 (helper)

  Shared Zod schema for all optional body measurement fields (nullable numbers used across create and update tools).

  const bodyMeasurementFieldsSchema = {
  	weightKg: zNullableNumber.describe("Body weight in kilograms"),
  	leanMassKg: zNullableNumber.describe("Lean body mass in kilograms"),
  	fatPercent: zNullableNumber.describe("Body fat percentage"),
  	neckCm: zNullableNumber.describe("Neck circumference in centimeters"),
  	shoulderCm: zNullableNumber.describe("Shoulder circumference in centimeters"),
  	chestCm: zNullableNumber.describe("Chest circumference in centimeters"),
  	leftBicepCm: zNullableNumber.describe(
  		"Left bicep circumference in centimeters",
  	),
  	rightBicepCm: zNullableNumber.describe(
  		"Right bicep circumference in centimeters",
  	),
  	leftForearmCm: zNullableNumber.describe(
  		"Left forearm circumference in centimeters",
  	),
  	rightForearmCm: zNullableNumber.describe(
  		"Right forearm circumference in centimeters",
  	),
  	abdomen: zNullableNumber.describe("Abdomen circumference in centimeters"),
  	waist: zNullableNumber.describe("Waist circumference in centimeters"),
  	hips: zNullableNumber.describe("Hips circumference in centimeters"),
  	leftThigh: zNullableNumber.describe(
  		"Left thigh circumference in centimeters",
  	),
  	rightThigh: zNullableNumber.describe(
  		"Right thigh circumference in centimeters",
  	),
  	leftCalf: zNullableNumber.describe("Left calf circumference in centimeters"),
  	rightCalf: zNullableNumber.describe(
  		"Right calf circumference in centimeters",
  	),
  } as const;

• src/tools/body-measurements.ts:97-248 (registration)

  Registration function that registers all body measurement tools on the MCP server. Called from src/index.ts line 79.

  export function registerBodyMeasurementTools(
  	server: McpServer,
  	hevyClient: HevyClient | null,
  ) {
  	// Get body measurements (paginated list)
  	const getBodyMeasurementsSchema = {
  		page: z.coerce.number().int().gte(1).default(1),
  		pageSize: z.coerce.number().int().gte(1).lte(10).default(10),
  	} as const;
  	type GetBodyMeasurementsParams = InferToolParams<
  		typeof getBodyMeasurementsSchema
  	>;
  
  	server.tool(
  		"get-body-measurements",
  		"Get a paginated list of body measurements for the authenticated user. Returns measurements including weight, body fat, and various circumference measurements.",
  		getBodyMeasurementsSchema,
  		withErrorHandling(async (args: GetBodyMeasurementsParams) => {
  			if (!hevyClient) {
  				throw new Error(
  					"API client not initialized. Please provide HEVY_API_KEY.",
  				);
  			}
  			const { page, pageSize } = args;
  			const data: GetV1BodyMeasurements200 =
  				await hevyClient.getBodyMeasurements({
  					page,
  					pageSize,
  				});
  
  			const measurements =
  				data?.body_measurements?.map((measurement: BodyMeasurement) =>
  					formatBodyMeasurement(measurement),
  				) || [];
  
  			if (measurements.length === 0) {
  				return createEmptyResponse(
  					"No body measurements found for the specified parameters",
  				);
  			}
  
  			return createJsonResponse(measurements);
  		}, "get-body-measurements"),
  	);
  
  	// Get single body measurement by date
  	const getBodyMeasurementSchema = {
  		date: z
  			.string()
  			.regex(/^\d{4}-\d{2}-\d{2}$/, "Date must be in YYYY-MM-DD format")
  			.describe("The date of the body measurement (YYYY-MM-DD)"),
  	} as const;
  	type GetBodyMeasurementParams = InferToolParams<
  		typeof getBodyMeasurementSchema
  	>;
  
  	server.tool(
  		"get-body-measurement",
  		"Get a single body measurement by date. Returns all measurement fields for the specified date.",
  		getBodyMeasurementSchema,
  		withErrorHandling(async (args: GetBodyMeasurementParams) => {
  			if (!hevyClient) {
  				throw new Error(
  					"API client not initialized. Please provide HEVY_API_KEY.",
  				);
  			}
  			const { date } = args;
  			const data: GetV1BodyMeasurementsDate200 =
  				await hevyClient.getBodyMeasurement(date);
  
  			if (!data) {
  				return createEmptyResponse(
  					`No body measurement found for date ${date}`,
  				);
  			}
  
  			return createJsonResponse(formatBodyMeasurement(data));
  		}, "get-body-measurement"),
  	);
  
  	// Create body measurement
  	const createBodyMeasurementSchema = {
  		date: z
  			.string()
  			.regex(/^\d{4}-\d{2}-\d{2}$/, "Date must be in YYYY-MM-DD format")
  			.describe(
  				"The date of the body measurement (YYYY-MM-DD). Must be unique — returns 409 if an entry already exists for this date.",
  			),
  		...bodyMeasurementFieldsSchema,
  	} as const;
  	type CreateBodyMeasurementParams = InferToolParams<
  		typeof createBodyMeasurementSchema
  	>;
  
  	server.tool(
  		"create-body-measurement",
  		"Create a body measurement entry for a given date. All measurement fields are optional. Returns 409 if an entry already exists for that date — use update-body-measurement instead.",
  		createBodyMeasurementSchema,
  		withErrorHandling(async (args: CreateBodyMeasurementParams) => {
  			if (!hevyClient) {
  				throw new Error(
  					"API client not initialized. Please provide HEVY_API_KEY.",
  				);
  			}
  			const { date, ...fields } = args;
  			await hevyClient.createBodyMeasurement({
  				date,
  				...buildMeasurementPayload(fields),
  			});
  
  			return createTextResponse(
  				`Body measurement for ${date} created successfully.`,
  			);
  		}, "create-body-measurement"),
  	);
  
  	// Update body measurement
  	const updateBodyMeasurementSchema = {
  		date: z
  			.string()
  			.regex(/^\d{4}-\d{2}-\d{2}$/, "Date must be in YYYY-MM-DD format")
  			.describe(
  				"The date of the body measurement to update (YYYY-MM-DD). Must already exist — returns 404 otherwise.",
  			),
  		...bodyMeasurementFieldsSchema,
  	} as const;
  	type UpdateBodyMeasurementParams = InferToolParams<
  		typeof updateBodyMeasurementSchema
  	>;
  
  	server.tool(
  		"update-body-measurement",
  		"Update an existing body measurement entry for a given date. All fields are overwritten — omitted fields are set to null. Returns 404 if no entry exists for the date.",
  		updateBodyMeasurementSchema,
  		withErrorHandling(async (args: UpdateBodyMeasurementParams) => {
  			if (!hevyClient) {
  				throw new Error(
  					"API client not initialized. Please provide HEVY_API_KEY.",
  				);
  			}
  			const { date, ...fields } = args;
  			await hevyClient.updateBodyMeasurement(
  				date,
  				buildMeasurementPayload(fields),
  			);
  
  			return createTextResponse(
  				`Body measurement for ${date} updated successfully.`,
  			);
  		}, "update-body-measurement"),
  	);
  }