#+title: GPTel: A simple ChatGPT client for Emacs

GPTel is a simple, no-frills ChatGPT client for Emacs.

[[file:img/gptel.png]]

- Requires an [[https://platform.openai.com/account/api-keys][OpenAI API key]].
- No external dependencies, only Emacs. Also, it's async.
- Interact with ChatGPT from any buffer in Emacs.
- ChatGPT's responses are in Markdown or Org markup (configurable).
- Supports conversations (not just one-off queries) and multiple independent sessions.
- You can go back and edit your previous prompts, or even ChatGPT's previous responses when continuing a conversation. These will be fed back to ChatGPT.

** Installation

GPTel is on MELPA. Install it with =M-x package-install⏎= =gptel=.

(Optional: Install =markdown-mode=.)

*** Straight
#+begin_src emacs-lisp
  (straight-use-package 'gptel)
#+end_src

Installing the =markdown-mode= package is optional.

*** Manual
Clone this repository and load this file:
#+begin_src emacs-lisp
(add-to-list 'load-path "/path/to/gptel/")
(require 'gptel)
#+end_src

Installing the =markdown-mode= package is optional.

** Usage

Procure an [[https://platform.openai.com/account/api-keys][OpenAI API key]].

Optional: Set =gptel-api-key= to the key or to a function that returns the key (more secure).

*** In a dedicated chat buffer:

1. Run =M-x gptel= to start or switch to the ChatGPT buffer. It will ask you for the key if you skipped the previous step. Run it with a prefix-arg (=C-u M-x gptel=) to start a new session.

2. In the gptel buffer, send your prompt with =M-x gptel-send=, bound to =C-c RET=.

3. Set chat parameters by calling =gptel-send= with a prefix argument (=C-u C-c RET=):

[[https://user-images.githubusercontent.com/8607532/224946059-9b918810-ab8b-46a6-b917-549d50c908f2.png]]

That's it. You can go back and edit previous prompts and responses if you want.

The default mode is =markdown-mode= if available, else =text-mode=.  You can set =gptel-default-mode= to =org-mode= if desired.

*** In any buffer:

1. Select a region of text and call =M-x gptel-send=. The response will be inserted below your region.
   
2. You can select both the original prompt and the response and call =M-x gptel-send= again to continue the conversation.

3. Call =M-x gptel-send= with a prefix argument to set chat parameters, or to start a dedicated session from the selected region:

[[https://user-images.githubusercontent.com/8607532/224949877-08c44cb4-7bff-4ffc-963a-16fef7a4271f.png]]

** Why another ChatGPT client?

Existing Emacs clients don't /reliably/ let me use it the simple way I can in the browser.  They will get better, but I wanted something for now.

Also, AI-assisted work is a new way to use Emacs.  It's not yet clear what the best Emacs interface to tools like it is.

- Should it be part of CAPF (=completions-at-point-functions=)?
- A dispatch menu from anywhere that can act on selected regions?
- A comint/shell-style REPL?
- One-off queries in the minibuffer (like =shell-command=)?
- A refactoring tool in code buffers?
- An =org-babel= interface?

Maybe all of these, I don't know yet. As a start, I wanted to replicate the web browser usage pattern so I can build from there -- and don't need to switch to the browser every time. The code is fairly simple right now.

** Will you add feature X?

Maybe, I'd like to experiment a bit first.