The Effect client

createEffectClient from @trpc12/trpc/effect returns an Effect per call and a Stream per subscription. Typed errors are in the error channel, and interrupting the fiber aborts the request.
import { function httpLink<TOpts extends HttpLinkOptions>(opts: TOpts): TrpcLink<HttpLinkDecl<TOpts>>httpLink, function routerType<TRouter>(): RouterType<TRouter>routerType } from '@trpc12/trpc/client';
import { function createEffectClient<TSource, const TLinks extends ReadonlyArray<TrpcLink<any, RouterOf<TSource>>>>(opts: TypedClientOptions<TSource, TLinks> & DuplicateSwitchCheck<TLinks>): EffectClient<RouterOf<TSource>, LinksContext<TLinks>, LinksTypes<TLinks>>createEffectClient } from '@trpc12/trpc/effect';
import { import EffectEffect } from 'effect';

const const client: EffectClient<{
    post: {
        byId: BuildProcedure<InputDef<RootDef<Context, {}>, ZodObject<{
            id: ZodString;
        }, $strip>>, "query", {
            output: Post;
            errors: TrpcError<"NOT_FOUND", {
                id: string;
            }>;
            services: never;
            unmapped: never;
        }>;
        list: BuildProcedure<RootDef<Context, {}>, "query", {
            output: Post[];
            errors: never;
            services: never;
            unmapped: never;
        }>;
        create: BuildProcedure<InputDef<With<RootDef<Context, {}>, {
            ctx: Context;
            ctxAdded: {
                ...;
            };
            inputOut: Unset;
            errors: TrpcError<...>;
            shorts: never;
        }>, ZodObject<...>>, "mutation", {
            ...;
        }>;
    };
}, {}, LinksTypes<...>>client = createEffectClient<RouterType<{
    post: {
        byId: BuildProcedure<InputDef<RootDef<Context, {}>, ZodObject<{
            id: ZodString;
        }, $strip>>, "query", {
            output: Post;
            errors: TrpcError<"NOT_FOUND", {
                id: string;
            }>;
            services: never;
            unmapped: never;
        }>;
        list: BuildProcedure<RootDef<Context, {}>, "query", {
            output: Post[];
            errors: never;
            services: never;
            unmapped: never;
        }>;
        create: BuildProcedure<InputDef<With<RootDef<Context, {}>, {
            ctx: Context;
            ctxAdded: {
                ...;
            };
            inputOut: Unset;
            errors: TrpcError<...>;
            shorts: never;
        }>, ZodObject<...>>, "mutation", {
            ...;
        }>;
    };
}>, readonly [...]>(opts: TypedClientOptions<...>): EffectClient<...>createEffectClient({
  TypedClientOptions<RouterType<{ post: { byId: BuildProcedure<InputDef<RootDef<Context, {}>, ZodObject<{ id: ZodString; }, $strip>>, "query", { output: Post; errors: TrpcError<...>; services: never; unmapped: never; }>; list: BuildProcedure<...>; create: BuildProcedure<...>; }; }>, readonly [...]>.router: RouterType<{
    post: {
        byId: BuildProcedure<InputDef<RootDef<Context, {}>, ZodObject<{
            id: ZodString;
        }, $strip>>, "query", {
            output: Post;
            errors: TrpcError<"NOT_FOUND", {
                id: string;
            }>;
            services: never;
            unmapped: never;
        }>;
        list: BuildProcedure<RootDef<Context, {}>, "query", {
            output: Post[];
            errors: never;
            services: never;
            unmapped: never;
        }>;
        create: BuildProcedure<InputDef<With<RootDef<Context, {}>, {
            ctx: Context;
            ctxAdded: {
                ...;
            };
            inputOut: Unset;
            errors: TrpcError<...>;
            shorts: never;
        }>, ZodObject<...>>, "mutation", {
            ...;
        }>;
    };
}>router: routerType<{
    post: {
        byId: BuildProcedure<InputDef<RootDef<Context, {}>, ZodObject<{
            id: ZodString;
        }, $strip>>, "query", {
            output: Post;
            errors: TrpcError<"NOT_FOUND", {
                id: string;
            }>;
            services: never;
            unmapped: never;
        }>;
        list: BuildProcedure<RootDef<Context, {}>, "query", {
            output: Post[];
            errors: never;
            services: never;
            unmapped: never;
        }>;
        create: BuildProcedure<InputDef<With<RootDef<Context, {}>, {
            ctx: Context;
            ctxAdded: {
                ...;
            };
            inputOut: Unset;
            errors: TrpcError<...>;
            shorts: never;
        }>, ZodObject<...>>, "mutation", {
            ...;
        }>;
    };
}>(): RouterType<...>routerType<type AppRouter = {
    post: {
        byId: BuildProcedure<InputDef<RootDef<Context, {}>, ZodObject<{
            id: ZodString;
        }, $strip>>, "query", {
            output: Post;
            errors: TrpcError<"NOT_FOUND", {
                id: string;
            }>;
            services: never;
            unmapped: never;
        }>;
        list: BuildProcedure<RootDef<Context, {}>, "query", {
            output: Post[];
            errors: never;
            services: never;
            unmapped: never;
        }>;
        create: BuildProcedure<InputDef<With<RootDef<Context, {}>, {
            ctx: Context;
            ctxAdded: {
                ...;
            };
            inputOut: Unset;
            errors: TrpcError<...>;
            shorts: never;
        }>, ZodObject<...>>, "mutation", {
            ...;
        }>;
    };
}AppRouter>(),
  TypedClientOptions<RouterType<{ post: { byId: BuildProcedure<InputDef<RootDef<Context, {}>, ZodObject<{ id: ZodString; }, $strip>>, "query", { output: Post; errors: TrpcError<...>; services: never; unmapped: never; }>; list: BuildProcedure<...>; create: BuildProcedure<...>; }; }>, readonly [...]>.links: readonly [TrpcLink<{
    form: JsonForm;
    provides: "response";
}, any>]links: [httpLink<{
    url: string;
}>(opts: {
    url: string;
}): TrpcLink<{
    form: JsonForm;
    provides: "response";
}, any>httpLink({ url: stringurl: 'http://localhost:3000/trpc' })],
});

const const program: Effect.Effect<string, ClientError<TrpcError<"NOT_FOUND", {
    id: string;
}> | InputValidationError<{
    readonly code: "invalid_type";
    readonly expected: $ZodInvalidTypeExpected;
    readonly path: readonly [] | readonly ["id"];
    readonly message: string;
} | {
    readonly code: "too_big";
    readonly origin: "number" | "int" | "bigint" | "date" | "string" | "array" | "set" | "file" | (string & {});
    readonly maximum: string | number;
    readonly inclusive?: boolean | undefined;
    readonly exact?: boolean | undefined;
    readonly path: readonly [] | readonly ["id"];
    readonly message: string;
} | ... 9 more ... | {
    ...;
}>>, never>program = import EffectEffect.const gen: <Effect.Effect<{
    id: string;
    title: string;
    author: string | null;
    createdAt: string;
}, ClientError<TrpcError<"NOT_FOUND", {
    id: string;
}> | InputValidationError<{
    readonly code: "invalid_type";
    readonly expected: $ZodInvalidTypeExpected;
    readonly path: readonly [] | readonly ["id"];
    readonly message: string;
} | {
    readonly code: "too_big";
    readonly origin: "number" | "int" | "bigint" | "date" | "string" | "array" | "set" | "file" | (string & {});
    readonly maximum: string | number;
    readonly inclusive?: boolean | undefined;
    readonly exact?: boolean | undefined;
    readonly path: readonly [] | readonly [...];
    readonly message: string;
} | ... 9 more ... | {
    ...;
}>>, never>, string>(f: () => Generator<...>) => Effect.Effect<...> (+1 overload)gen(function* () {
  const const post: {
    id: string;
    title: string;
    author: string | null;
    createdAt: string;
}post = yield* const client: EffectClient<{
    post: {
        byId: BuildProcedure<InputDef<RootDef<Context, {}>, ZodObject<{
            id: ZodString;
        }, $strip>>, "query", {
            output: Post;
            errors: TrpcError<"NOT_FOUND", {
                id: string;
            }>;
            services: never;
            unmapped: never;
        }>;
        list: BuildProcedure<RootDef<Context, {}>, "query", {
            output: Post[];
            errors: never;
            services: never;
            unmapped: never;
        }>;
        create: BuildProcedure<InputDef<With<RootDef<Context, {}>, {
            ctx: Context;
            ctxAdded: {
                ...;
            };
            inputOut: Unset;
            errors: TrpcError<...>;
            shorts: never;
        }>, ZodObject<...>>, "mutation", {
            ...;
        }>;
    };
}, {}, LinksTypes<...>>client.post: EffectClient<{
    byId: BuildProcedure<InputDef<RootDef<Context, {}>, ZodObject<{
        id: ZodString;
    }, $strip>>, "query", {
        output: Post;
        errors: TrpcError<"NOT_FOUND", {
            id: string;
        }>;
        services: never;
        unmapped: never;
    }>;
    list: BuildProcedure<RootDef<Context, {}>, "query", {
        output: Post[];
        errors: never;
        services: never;
        unmapped: never;
    }>;
    create: BuildProcedure<InputDef<With<RootDef<Context, {}>, {
        ctx: Context;
        ctxAdded: {
            ...;
        };
        inputOut: Unset;
        errors: TrpcError<...>;
        shorts: never;
    }>, ZodObject<...>>, "mutation", {
        ...;
    }>;
}, {}, LinksTypes<...>>post.byId: {
    query(input: {
        id: string;
    }, opts?: CallOptions<{}> | undefined): Effect.Effect<{
        id: string;
        title: string;
        author: string | null;
        createdAt: string;
    }, ClientError<TrpcError<"NOT_FOUND", {
        id: string;
    }> | InputValidationError<{
        readonly code: "invalid_type";
        readonly expected: $ZodInvalidTypeExpected;
        readonly path: readonly [] | readonly ["id"];
        readonly message: string;
    } | {
        readonly code: "too_big";
        readonly origin: "number" | "int" | "bigint" | "date" | "string" | "array" | "set" | "file" | (string & {});
        readonly maximum: string | number;
        readonly inclusive?: boolean | undefined;
        readonly exact?: boolean | undefined;
        readonly path: readonly [] | readonly [...];
        readonly message: string;
    } | ... 9 more ... | {
        ...;
    }>>, never>;
}byId.function query(input: {
    id: string;
}, opts?: CallOptions<{}> | undefined): Effect.Effect<{
    id: string;
    title: string;
    author: string | null;
    createdAt: string;
}, ClientError<TrpcError<"NOT_FOUND", {
    id: string;
}> | InputValidationError<{
    readonly code: "invalid_type";
    readonly expected: $ZodInvalidTypeExpected;
    readonly path: readonly [] | readonly ["id"];
    readonly message: string;
} | {
    readonly code: "too_big";
    readonly origin: "number" | "int" | "bigint" | "date" | "string" | "array" | "set" | "file" | (string & {});
    readonly maximum: string | number;
    readonly inclusive?: boolean | undefined;
    readonly exact?: boolean | undefined;
    readonly path: readonly [] | readonly [...];
    readonly message: string;
} | ... 9 more ... | {
    ...;
}>>, never>query({ id: stringid: '1' });
  return const post: {
    id: string;
    title: string;
    author: string | null;
    createdAt: string;
}post.title: stringtitle;
});
The links are the same as the Promise client's (Links). For spans around calls, see Tracing.