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Version: 10.x

Metadata

Procedure metadata allows you to add an optional procedure specific meta property which will be available in all middleware function parameters.

tip

Use metadata together with trpc-openapi if you want to expose REST-compatible endpoints for your application.

Create router with typed metadata

tsx
import { initTRPC } from '@trpc/server';
// [...]
interface Meta {
authRequired: boolean;
}
export const t = initTRPC.context<Context>().meta<Meta>().create();
export const appRouter = t.router({
// [...]
});
tsx
import { initTRPC } from '@trpc/server';
// [...]
interface Meta {
authRequired: boolean;
}
export const t = initTRPC.context<Context>().meta<Meta>().create();
export const appRouter = t.router({
// [...]
});

Example with per route authentication settings

server.ts
tsx
import { initTRPC } from '@trpc/server';
// [...]
interface Meta {
authRequired: boolean;
}
export const t = initTRPC.context<Context>().meta<Meta>().create();
const isAuthed = t.middleware(async (opts) => {
const { meta, next, ctx } = opts;
// only check authorization if enabled
if (meta?.authRequired && !ctx.user) {
throw new TRPCError({ code: 'UNAUTHORIZED' });
}
return next();
});
export const authedProcedure = t.procedure.use(isAuthed);
export const appRouter = t.router({
hello: authedProcedure.meta({ authRequired: false }).query(() => {
return {
greeting: 'hello world',
};
}),
protectedHello: authedProcedure.meta({ authRequired: true }).query(() => {
return {
greeting: 'hello-world',
};
}),
});
server.ts
tsx
import { initTRPC } from '@trpc/server';
// [...]
interface Meta {
authRequired: boolean;
}
export const t = initTRPC.context<Context>().meta<Meta>().create();
const isAuthed = t.middleware(async (opts) => {
const { meta, next, ctx } = opts;
// only check authorization if enabled
if (meta?.authRequired && !ctx.user) {
throw new TRPCError({ code: 'UNAUTHORIZED' });
}
return next();
});
export const authedProcedure = t.procedure.use(isAuthed);
export const appRouter = t.router({
hello: authedProcedure.meta({ authRequired: false }).query(() => {
return {
greeting: 'hello world',
};
}),
protectedHello: authedProcedure.meta({ authRequired: true }).query(() => {
return {
greeting: 'hello-world',
};
}),
});

Default meta, chaining, and shallow merging

You can set default values for your meta type, and if you chain meta on top of a base procedure it will be shallow merged.

tsx
import { initTRPC } from '@trpc/server';
interface Meta {
authRequired: boolean;
role?: 'user' | 'admin'
}
export const t = initTRPC
.context<Context>()
.meta<Meta>()
.create({
// Set a default value
defaultMeta: { authRequired: false }
});
const publicProcedure = t.procedure
// ^ Default Meta: { authRequired: false }
const authProcedure = publicProcedure
.use(authMiddleware)
.meta({
authRequired: true;
role: 'user'
});
// ^ Meta: { authRequired: true, role: 'user' }
const adminProcedure = authProcedure
.meta({
role: 'admin'
});
// ^ Meta: { authRequired: true, role: 'admin' }
tsx
import { initTRPC } from '@trpc/server';
interface Meta {
authRequired: boolean;
role?: 'user' | 'admin'
}
export const t = initTRPC
.context<Context>()
.meta<Meta>()
.create({
// Set a default value
defaultMeta: { authRequired: false }
});
const publicProcedure = t.procedure
// ^ Default Meta: { authRequired: false }
const authProcedure = publicProcedure
.use(authMiddleware)
.meta({
authRequired: true;
role: 'user'
});
// ^ Meta: { authRequired: true, role: 'user' }
const adminProcedure = authProcedure
.meta({
role: 'admin'
});
// ^ Meta: { authRequired: true, role: 'admin' }