Encoders Reference

Overview

jsonableEncode converts complex Zig values into a std.json.Value tree that can be further manipulated or serialized. This is the Zig equivalent of FastAPI's jsonable_encoder.

jsonableEncode

pub fn jsonableEncode(allocator: std.mem.Allocator, value: anytype) !std.json.Value

Recursively converts a Zig value into a std.json.Value tree.

Supported Types

Return Value

Returns a std.json.Value which is a tagged union:

pub const Value = union(enum) {
    null,
    bool: bool,
    integer: i64,
    float: f64,
    number_string: []const u8,
    string: []const u8,
    array: Array,
    object: ObjectMap,
};

Memory Management

• Strings are not copied -- they reference the original data.
• Arrays and objects allocate using the provided allocator and must be freed by the caller.

Example

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

const User = struct {
    name: []const u8,
    age: i32,
    active: bool,
    tags: []const []const u8,
};

fn handler(allocator: std.mem.Allocator) !zigmund.Response {
    const user = User{
        .name = "Alice",
        .age = 30,
        .active = true,
        .tags = &.{ "admin", "editor" },
    };

    var encoded = try zigmund.jsonableEncode(allocator, user);
    defer encoded.object.deinit();

    // Manipulate the JSON tree
    try encoded.object.put("extra", .{ .string = "computed" });

    // Serialize to string
    const json_str = try std.json.stringifyAlloc(allocator, encoded, .{});
    defer allocator.free(json_str);

    return zigmund.Response.json(allocator, user);
}

For most use cases, Response.json(allocator, value) directly serializes Zig values to JSON without needing jsonableEncode. Use jsonableEncode when you need to inspect or modify the JSON tree before serialization.