@effect-ak/tg-bot-client

Type-safe HTTP client for the Telegram Bot API. One execute method covers every API method, files are encoded to FormData automatically, errors are typed. Native fetch, zero runtime dependencies — runs on Node.js 18+, Bun, Deno, Cloudflare Workers, browsers.

Types come from @effect-ak/tg-bot-api; the bot framework @effect-ak/tg-bot is built on this client.

Installation

npm install @effect-ak/tg-bot-client

The Bot API types are re-exported under a subpath, so this is the only package you need:

import { makeTgBotClient } from "@effect-ak/tg-bot-client"
import type { Message, Update } from "@effect-ak/tg-bot-client/api"

Quick Start

import { makeTgBotClient } from "@effect-ak/tg-bot-client"

const client = makeTgBotClient({ bot_token: "YOUR_BOT_TOKEN" })

// Method names are snake_case, exactly as in the official docs
const message = await client.execute("send_message", {
  chat_id: 123456789,
  text: "Hello!"
})

API Surface

makeTgBotClient({ bot_token, base_url?, timeout? }): TgBotClient

interface TgBotClient {
  execute(method, params, options?): Promise<Result>            // throws TgBotClientError
  executeSafe(method, params, options?): Promise<ClientResult>  // never throws
  getFile({ fileId }): Promise<TgFile>                          // download by file_id
  getFileSafe({ fileId }): Promise<ClientResult<TgFile>>
}

type ClientResult<T> = { ok: true; data: T } | { ok: false; error: ClientErrorReason }
type ClientErrorReason =
  | { _tag: "NotOkResponse"; errorCode?: number; details?: string }  // Telegram said ok:false
  | { _tag: "RequestTimeout"; timeoutMs: number }
  | { _tag: "NotJsonResponse" | "UnexpectedResponse" | "ClientInternalError" | "UnableToGetFile"; ... }

• Method and parameter names match https://core.telegram.org/bots/api in snake_case (send_message, edit_message_text, answer_callback_query). Both are autocompleted; return types are inferred.
• Files: pass { file_content: Uint8Array, file_name: string } wherever the API accepts InputFile — the client switches to multipart automatically. Or pass a file_id / URL string.
• Message effects: message_effect_id accepts an emoji key of MESSAGE_EFFECTS ("🔥" | "👍" | "👎" | "❤️" | "🎉" | "💩") and is mapped to the real id.
• Errors: execute throws TgBotClientError (error.reason is the tagged union above); executeSafe returns the union — pick one style and stick to it.
• Options: { timeout } per call; base_url for a self-hosted Bot API server.

Examples

// Safe variant
const result = await client.executeSafe("get_chat", { chat_id: 1 })
if (!result.ok) console.error(result.error._tag)

// Upload a file
await client.execute("send_document", {
  chat_id,
  document: { file_content: new TextEncoder().encode("hi"), file_name: "hi.txt" },
  caption: "Generated on the fly"
})

// Download a file
const file = await client.getFile({ fileId })
file.content // ArrayBuffer

Documentation

• Guide: tg-bot-sdk.website/client/usage
• Bot API reference (one page per method): https://tg-bot-sdk.website/api/
• For LLMs / coding agents: https://tg-bot-sdk.website/llms.txt

License

MIT