validation fail for params of type numbers. expects a string

[alzalabany]

example: the following route if you open http://127.0.0.1:3003/x/12 it will fail expected number, received string.

fastify.withTypeProvider<ZodTypeProvider>().get("/x/:n", {
    schema: {
      params: z.object({ n: z.number() }),
      response: {
        200: z.object({ n: z.number() }),
      },
    },
    handler: ({ params: { n } }) => {
      return { n };
    },
  });

[kibertoad]

You need to use .coerce for query and path params, as these always are passed as strings, because fastify has no way to establish their true type

[zhangskills]

example: the following route if you open http://127.0.0.1:3003/x/12 it will fail expected number, received string.

fastify.withTypeProvider<ZodTypeProvider>().get("/x/:n", {
    schema: {
      params: z.object({ n: z.number() }),
      response: {
        200: z.object({ n: z.number() }),
      },
    },
    handler: ({ params: { n } }) => {
      return { n };
    },
  });

just like this:

fastify.withTypeProvider<ZodTypeProvider>().get("/x/:n", {
    schema: {
        params: z.object({n: z.coerce.number()}),
        response: {
            200: z.object({n: z.number()}),
        },
    },
    handler: ({params: {n}}) => {
        return {n};
    },
});