Add gptel and elysium

init.el

 (require 'init-latex)
 (require 'init-mu4e)
 (require 'init-literate-calc)
+;; AI
+(require 'init-gptel)
+(require 'init-elysium)
 
 (when *spell-check-support-enabled*
   (require 'init-spelling))

lisp/init-elysium.el

+;;; package --- elysium
+;;; Commentary:
+;;; https://github.com/lanceberge/elysium
+;;; Code:
+
+;; Elysium applies AI-generated code changes to the buffer as
+;; smerge-style hunks.  It queries LLMs through gptel, so the
+;; backend and model are those from init-gptel.el (OpenRouter by
+;; default, Venice also available).
+
+(use-package elysium
+  :ensure t
+  :defer t
+  :custom
+  ;; Below are the default values
+  (elysium-window-size 0.33) ; The elysium buffer will be 1/3 your screen
+  (elysium-window-style 'vertical)) ; Can be customized to horizontal
+
+(provide 'init-elysium)
+
+;;; init-elysium.el ends here

lisp/init-gptel.el

+;;; package --- gptel
+;;; Commentary:
+;;; A simple LLM client for Emacs.
+;;; https://github.com/karthink/gptel
+;;; Code:
+
+(use-package gptel
+  :ensure t
+  :defer t
+  :config
+  ;; Major mode used for chat buffers: 'org-mode or 'markdown-mode.
+  (setq gptel-default-mode 'org-mode)
+
+  ;; API keys: each backend below uses #'gptel-api-key-from-auth-source,
+  ;; which looks up the backend's host with login "apikey" in auth-source.
+  ;; Add these lines to ~/.authinfo.gpg:
+  ;;
+  ;;   machine openrouter.ai login apikey password <OPENROUTER-KEY>
+  ;;   machine api.venice.ai login apikey password <VENICE-KEY>
+  ;;
+  ;; (Create keys at https://openrouter.ai/keys and
+  ;; https://venice.ai/settings/api-key respectively.)
+  ;;
+  ;; Note: OpenCode cannot be used as a gptel backend: its HTTP API is
+  ;; for driving agent sessions, not an OpenAI-compatible LLM endpoint,
+  ;; and its own provider authenticates with an account, not an API key.
+
+  ;; OpenRouter (default backend): OpenAI-compatible gateway to many
+  ;; providers.  Model IDs can be browsed at https://openrouter.ai/models
+  (setq gptel-backend
+        (gptel-make-openai "OpenRouter"
+                           :host "openrouter.ai"
+                           :endpoint "/api/v1/chat/completions"
+                           :key #'gptel-api-key-from-auth-source
+                           :stream t
+                           :models '(anthropic/claude-sonnet-5.5
+                                     anthropic/claude-haiku-5.5
+                                     openai/gpt-6.1-sol
+                                     google/gemini-4-argon
+                                     z-ai/glm-5.3-prime
+                                     z-ai/glm-5.3-flashx
+                                     z-ai/glm-5.3-flash
+                                     z-ai/glm-5.2
+                                     deepseek/deepseek-v4.1-flash
+                                     qwen/qwen3.8-max-prime
+                                     x-ai/grok-4.7
+                                     moonshotai/kimi-k3.1-pro))
+        ;; Change the default model here, or per-session with the menu
+        ;; (C-u C-c RET in a gptel buffer, then -m).
+        gptel-model 'z-ai/glm-5.3-prime)
+
+  ;; Venice (https://venice.ai): privacy-oriented, OpenAI-compatible
+  ;; API with uncensored models.  Registered but not the default: pick
+  ;; it per-session with `M-x gptel-venice' (below) or the menu
+  ;; (C-u C-c RET, then -m), or make it the default:
+  ;;
+  ;; (setq gptel-backend (gptel-get-backend "Venice")
+  ;;       gptel-model 'zai-org-glm-5)
+  (gptel-make-openai "Venice"
+                     :host "api.venice.ai"
+                     :endpoint "/api/v1/chat/completions"
+                     :key #'gptel-api-key-from-auth-source
+                     :stream t
+                     :models '(zai-org-glm-5     ;Venice's default model
+                               z-ai-glm-5-3
+                               z-ai-glm-5-3-flash
+                               venice-uncensored-1-2
+                               claude-sonnet-5-5
+                               claude-opus-5-5
+                               deepseek-v4-1-flash
+                               kimi-k3-1-pro))
+
+  ;; In org chat buffers, only send the current heading's tree as
+  ;; context instead of the whole buffer:
+  ;;
+  ;; (setq gptel-org-branching-context t)
+  )
+
+;; Start or switch to a chat on a specific backend, without touching
+;; the global default.  An existing chat buffer keeps its chosen
+;; model; a new chat gets MODEL.
+(defun gptel--backend-chat (backend-name model)
+  "Start or switch to a gptel chat using BACKEND-NAME and MODEL.
+The global default backend is not changed."
+  (let* ((backend (gptel-get-backend backend-name))
+         (buffer (gptel (concat "*" backend-name "*"))))
+    (with-current-buffer buffer
+      (setq-local gptel-backend backend)
+      (unless (memq gptel-model (gptel-backend-models backend))
+        (setq-local gptel-model model)))
+    (display-buffer buffer gptel-display-buffer-action)
+    buffer))
+
+(defun gptel-openrouter ()
+  "Start or switch to a gptel chat using OpenRouter."
+  (interactive)
+  (require 'gptel)                 ;deferred by use-package above
+  (gptel--backend-chat "OpenRouter" 'z-ai/glm-5.3-prime))
+
+(defun gptel-venice ()
+  "Start or switch to a gptel chat using Venice."
+  (interactive)
+  (require 'gptel)
+  (gptel--backend-chat "Venice" 'zai-org-glm-5))
+
+;; Usage:
+;;   M-x gptel            start a dedicated chat buffer (default backend)
+;;   M-x gptel-openrouter start or switch to a chat on OpenRouter
+;;   M-x gptel-venice     start or switch to a chat on Venice
+;;   M-x gptel-send       send the region (or text up to point) from any buffer
+;;   M-x gptel-rewrite    rewrite/refactor the selected region
+;;   C-c RET              send the query
+;;   C-u C-c RET          menu: switch backend/model with -m, etc.
+;;
+;; Uncomment for global shortcuts:
+;; (global-set-key (kbd "C-c g") #'gptel)
+;; (global-set-key (kbd "C-c o") #'gptel-openrouter)
+;; (global-set-key (kbd "C-c v") #'gptel-venice)
+
+(provide 'init-gptel)
+
+;;; init-gptel.el ends here