Classify a request
Classify a support message and extract the fields needed for that case. A refund needs an order ID, while a bug report needs reproduction details.
Parse a tagged union
Pass the OpenRouter session from the shared setup. This is structured extraction, not the Decisions API.
const std = @import("std");
const instructor = @import("instructor");
const Refund = struct {
order_id: []const u8,
reason: []const u8,
};
const BugReport = struct {
component: []const u8,
reproduction: []const u8,
};
const FeatureRequest = struct {
feature: []const u8,
user_value: []const u8,
};
const Classification = union(enum) {
refund: Refund,
bug_report: BugReport,
feature_request: FeatureRequest,
};
const Decision = struct {
classification: Classification,
pub const jsonschema = .{
.name = "Decision",
.description = "Classify a message into exactly one typed case.",
};
};
fn classify(session: *instructor.Session(instructor.OpenAI)) !void {
const decision = try session.create(Decision, instructor.OpenAI.Request{
.model = "anthropic/claude-haiku-5.5",
.messages = &.{.{ .role = .user, .content = "Order A-991 arrived broken. Please refund it." }},
}, .{});
switch (decision.classification) {
.refund => |r| std.debug.print("refund {s}: {s}\n", .{ r.order_id, r.reason }),
.bug_report => |b| std.debug.print("bug {s}: {s}\n", .{ b.component, b.reproduction }),
.feature_request => |f| std.debug.print("feature {s}: {s}\n", .{ f.feature, f.user_value }),
}
}Handle each case
The outer Decision struct keeps the union inside an object field. Each union case has its own payload. An exhaustive switch gives you the correct fields for that case without optional fields for every possible outcome.
The type name Decision here does not imply probabilities. If you only need a team choice and urgency, use ticket routing with the Decisions API.
All extracted strings belong to the session. Copy them before resetting or deinitializing it. A typed refund classification is not authorization to issue a refund.