Initial commit: Telegram voice/video transcription bot in Zig

Long-polling bot that accepts voice messages and video notes,
sends them to Whisper STT API, and replies with transcription text.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/telegram.zig

@@ -0,0 +1,114 @@
+const std = @import("std");
+const http = @import("http.zig");
+const Allocator = std.mem.Allocator;
+
+pub const Voice = struct {
+    file_id: []const u8,
+    duration: ?i64 = null,
+};
+
+pub const VideoNote = struct {
+    file_id: []const u8,
+    duration: ?i64 = null,
+};
+
+pub const Message = struct {
+    message_id: i64,
+    chat: struct { id: i64 },
+    voice: ?Voice = null,
+    video_note: ?VideoNote = null,
+};
+
+pub const Update = struct {
+    update_id: i64,
+    message: ?Message = null,
+};
+
+pub const GetUpdatesResponse = struct {
+    ok: bool,
+    result: []Update = &.{},
+};
+
+pub const GetFileResponse = struct {
+    ok: bool,
+    result: ?struct {
+        file_path: ?[]const u8 = null,
+    } = null,
+};
+
+pub const SendMessageBody = struct {
+    chat_id: i64,
+    text: []const u8,
+    reply_to_message_id: ?i64 = null,
+};
+
+pub const TelegramBot = struct {
+    allocator: Allocator,
+    token: []const u8,
+    api_base: []const u8,
+
+    pub fn init(allocator: Allocator, token: []const u8) !TelegramBot {
+        const api_base = try std.fmt.allocPrint(allocator, "https://api.telegram.org/bot{s}", .{token});
+        return .{
+            .allocator = allocator,
+            .token = token,
+            .api_base = api_base,
+        };
+    }
+
+    pub fn deinit(self: *TelegramBot) void {
+        self.allocator.free(self.api_base);
+    }
+
+    pub fn getUpdates(self: *TelegramBot, offset: i64, timeout: u32) !std.json.Parsed(GetUpdatesResponse) {
+        const url = try std.fmt.allocPrint(self.allocator, "{s}/getUpdates?offset={d}&timeout={d}&allowed_updates=[\"message\"]", .{ self.api_base, offset, timeout });
+        defer self.allocator.free(url);
+
+        const body = try http.httpGet(self.allocator, url);
+        defer self.allocator.free(body);
+
+        return std.json.parseFromSlice(GetUpdatesResponse, self.allocator, body, .{ .ignore_unknown_fields = true });
+    }
+
+    pub fn getFilePath(self: *TelegramBot, file_id: []const u8) ![]u8 {
+        const url = try std.fmt.allocPrint(self.allocator, "{s}/getFile?file_id={s}", .{ self.api_base, file_id });
+        defer self.allocator.free(url);
+
+        const body = try http.httpGet(self.allocator, url);
+        defer self.allocator.free(body);
+
+        const parsed = try std.json.parseFromSlice(GetFileResponse, self.allocator, body, .{ .ignore_unknown_fields = true });
+        defer parsed.deinit();
+
+        if (parsed.value.result) |result| {
+            if (result.file_path) |fp| {
+                return self.allocator.dupe(u8, fp);
+            }
+        }
+        return error.HttpRequestFailed;
+    }
+
+    pub fn downloadFile(self: *TelegramBot, file_path: []const u8, dest: []const u8) !void {
+        const url = try std.fmt.allocPrint(self.allocator, "https://api.telegram.org/file/bot{s}/{s}", .{ self.token, file_path });
+        defer self.allocator.free(url);
+
+        try http.downloadToFile(self.allocator, url, dest);
+    }
+
+    pub fn sendMessage(self: *TelegramBot, chat_id: i64, text: []const u8, reply_to: ?i64) !void {
+        const url = try std.fmt.allocPrint(self.allocator, "{s}/sendMessage", .{self.api_base});
+        defer self.allocator.free(url);
+
+        const msg = SendMessageBody{
+            .chat_id = chat_id,
+            .text = text,
+            .reply_to_message_id = reply_to,
+        };
+
+        const json_body = std.json.Stringify.valueAlloc(self.allocator, msg, .{}) catch return;
+        defer self.allocator.free(json_body);
+
+        const resp = http.httpPostJson(self.allocator, url, json_body) catch return;
+        self.allocator.free(resp);
+    }
+};