feat: support Grok-4 by adding x.ai API category (xai)

Author: rebel1324

lua/gp/config.lua

@@ -72,6 +72,11 @@ local config = {
 			endpoint = "https://api.anthropic.com/v1/messages",
 			secret = os.getenv("ANTHROPIC_API_KEY"),
 		},
+		xai = {
+			disable = true,
+			endpoint = "https://api.x.ai/v1/chat/completions",
+			secret = os.getenv("XAI_API_KEY"),
+		},
 	},
 
 	-- prefix for all commands
@@ -310,6 +315,15 @@ local config = {
 			model = { model = "claude-3-5-haiku-latest", temperature = 0.8, top_p = 1 },
 			system_prompt = require("gp.defaults").code_system_prompt,
 		},
+		{
+			provider = "xai",
+			name = "Grok-4",
+			chat = false,
+			command = true,
+			-- string with model name or table with model name and parameters
+			model = { model = "grok-4-latest", temperature = 0 },
+			system_prompt = require("gp.defaults").code_system_prompt,
+		},
 		{
 			provider = "ollama",
 			name = "CodeOllamaLlama3.1-8B",

lua/gp/dispatcher.lua

@@ -169,38 +169,27 @@ D.prepare_payload = function(messages, model, provider)
 		return payload
 	end
 
-	if provider == "ollama" then
+	if provider == "xai" then
+		local system = ""
+		local i = 1
+		while i < #messages do
+			if messages[i].role == "system" then
+				system = system .. messages[i].content .. "\n"
+				table.remove(messages, i)
+			else
+				i = i + 1
+			end
+		end
+
 		local payload = {
 			model = model.model,
 			stream = true,
 			messages = messages,
+			system = system,
+			max_tokens = model.max_tokens or 4096,
+			temperature = math.max(0, math.min(2, model.temperature or 1)),
+			top_p = math.max(0, math.min(1, model.top_p or 1)),
 		}
-
-		if model.think ~= nil then
-			payload.think = model.think
-		end
-
-		local options = {}
-		if model.temperature then
-			options.temperature = math.max(0, math.min(2, model.temperature))
-		end
-		if model.top_p then
-			options.top_p = math.max(0, math.min(1, model.top_p))
-		end
-		if model.min_p then
-			options.min_p = math.max(0, math.min(1, model.min_p))
-		end
-		if model.num_ctx then
-			options.num_ctx = model.num_ctx
-		end
-		if model.top_k then
-			options.top_k = model.top_k
-		end
-
-		if next(options) then
-			payload.options = options
-		end
-
 		return payload
 	end
 
@@ -454,6 +443,14 @@ local query = function(buf, provider, payload, handler, on_exit, callback)
 		endpoint = render.template_replace(endpoint, "{{model}}", payload.model)
 	elseif provider == "ollama" then
 		headers = {}
+	elseif provider == "xai" then
+		-- currently xai only uses bearer token for authentication.
+		-- since I cannot sure its going to be that way for long time
+		-- branching out as another condition.
+		headers = {
+			"-H",
+			"Authorization: Bearer " .. bearer,
+		}
 	else -- default to openai compatible headers
 		headers = {
 			"-H",