OpenAPI Specification

HTTPX provides automatic OpenAPI 3.1.0 document generation directly from registered routes, type schemas, and metadata declarations.

Route Registration & Metadata

const std = @import("std");
const httpx = @import("httpx");

pub fn main() !void {
    var gpa: std.heap.DebugAllocator(.{}) = .init;
    defer _ = gpa.deinit();
    const allocator = gpa.allocator();
    const io = std.Io.Threaded.global_single_threaded.io();

    var server = try httpx.Server.init(allocator, io, .{
        .port = 8080,
        .enableDocs = true,
        .docs = .{
            .title = "Inventory API",
            .version = "1.0.0",
            .description = "Automated OpenAPI generation with HTTPX",
        },
    });
    defer server.deinit();

    try server.get("/api/items", itemsHandler);

    server.run();
}

fn itemsHandler(ctx: *httpx.Context) anyerror!httpx.Response {
    return ctx.renderJson(.{
        .items = [_]struct { id: u32, name: []const u8 }{
            .{ .id = 1, .name = "Widget" },
            .{ .id = 2, .name = "Gadget" },
        },
    });
}

Canonical JSON Specification

Visiting http://localhost:8080/openapi.json returns valid OpenAPI 3.1.0 JSON containing:

• openapi: "3.1.0"
• info: Title, version, description
• paths: Discovered routes, methods, and parameter schemas
• components: Reusable schemas and security definitions

Related

• Web: Documentation UIs
• Guide: OpenAPI
• Example: OpenAPI