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

[[https://melpa.org/#/gptel][file:https://melpa.org/packages/gptel-badge.svg]]

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

https://user-images.githubusercontent.com/8607532/230516812-86510a09-a2fb-4cbd-b53f-cc2522d05a13.mp4

https://user-images.githubusercontent.com/8607532/230516816-ae4a613a-4d01-4073-ad3f-b66fa73c6e45.mp4

- Requires an [[https://platform.openai.com/account/api-keys][OpenAI API key]].
- Async and fast (streams responses).
- 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.

GPTel uses Curl if available, but falls back to url-retrieve to work without external dependencies.
  
** 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 or download this repository and run =M-x package-install-file⏎= on the repository directory.

Installing the =markdown-mode= package is optional.

**** Doom Emacs
In =packages.el=
#+begin_src emacs-lisp
(package! gptel)
#+end_src

In =config.el=
#+begin_src emacs-lisp
(use-package! gptel
 :config
 (setq! gptel-api-key "your key"))
#+end_src

**** Spacemacs
After installation with =M-x package-install⏎= =gptel=

- Add =gptel= to =dotspacemacs-additional-packages=
- Add =(require 'gptel)= to =dotspacemacs/user-config=

** 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 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 (GPT model, directives etc) for this buffer, or to start a dedicated session from the selected region:

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

*** 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 (GPT model, directives etc) for the session 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.

** 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.