diff --git a/README.md b/README.md
index afea232..c93d2b2 100644
--- a/README.md
+++ b/README.md
@@ -33,7 +33,18 @@ Features may be incomplete, bugs are likely to occur and breaking changes may oc
 
 # Configuration
 
-no configuration currently.
+You can configure the plugin to use OpenRouter (an OpenAI-compatible proxy) by passing options to `setup`:
+
+```lua
+require('nes').setup({
+  provider = 'openrouter',                  -- 'copilot' (default) or 'openrouter'
+  api_key = 'YOUR_OPENROUTER_API_KEY',      -- required for openrouter
+  base_url = 'https://api.openrouter.ai/v1', -- optional, default "https://api.openrouter.ai/v1"
+  model = 'gpt-3.5-turbo',                  -- optional, default "gpt-3.5-turbo" for openrouter, "copilot-nes-v" for copilot
+})
+```
+
+Leave `provider = 'copilot'` (or omit `provider`) to use GitHub Copilot.
 
 # Usage
 
diff --git a/lua/nes/api.lua b/lua/nes/api.lua
index f12ec9d..89100ed 100644
--- a/lua/nes/api.lua
+++ b/lua/nes/api.lua
@@ -62,6 +62,66 @@ local function get_api_token()
 end
 
 function M.call(payload, callback)
+	local pkg = require("nes")
+	local opts = pkg.opts or {}
+	if opts.provider == "openrouter" then
+		local api_key = opts.api_key or vim.env.OPENROUTER_API_KEY
+		if not api_key then
+			error("OpenRouter API key not found")
+		end
+		local base_url = opts.base_url
+			or vim.env.OPENROUTER_API_BASE_URL
+			or "https://openrouter.ai/api/v1/chat/completions"
+		local open_payload = {
+			model = opts.model or "gpt-3.5-turbo",
+			messages = payload.messages,
+			temperature = payload.temperature,
+			top_p = payload.top_p,
+			n = payload.n,
+			stream = true,
+		}
+    local output = ""
+
+    curl.post(base_url, {
+
+			headers = {
+				["Content-Type"] = "application/json",
+				["Authorization"] = "Bearer " .. api_key,
+			},
+			on_error = function(err)
+				error("openrouter request error: " .. err)
+			end,
+			body = vim.json.encode(open_payload),
+      stream = function(_, chunk)
+        if not chunk then
+          return
+        end
+        if vim.startswith(chunk, "data: ") then
+          chunk = chunk:sub(6)
+        end
+        if chunk == "[DONE]" then
+          return
+        end
+        local ok, event = pcall(vim.json.decode, chunk)
+        if not ok then
+          return
+        end
+        if event and event.choices and event.choices[1] then
+          local choice = event.choices[1]
+          if choice.delta and choice.delta.content then
+            output = output .. choice.delta.content
+          end
+        end
+      end,
+      callback = function()
+        callback(output)
+        -- __AUTO_GENERATED_PRINT_VAR_START__
+        print([==[M.call#if#callback output:]==], vim.inspect(output)) -- __AUTO_GENERATED_PRINT_VAR_END__
+      end,
+    })
+    return
+  end
+
 	local api_token = get_api_token()
 	local base_url = api_token.endpoints.proxy or api_token.endpoints.api
 
diff --git a/lua/nes/context.lua b/lua/nes/context.lua
index 2a40781..9561d4f 100644
--- a/lua/nes/context.lua
+++ b/lua/nes/context.lua
@@ -90,6 +90,31 @@ function Context.new(bufnr)
 	return self
 end
 
+---@class CurrentVersion
+---@field text string
+
+---@class Context
+---@field filename string
+---@field original_code string
+---@field edits string
+---@field filetype string
+---@field current_version CurrentVersion
+
+---@class Message
+---@field role string
+---@field content string
+
+---@class Payload
+---@field messages Message[]
+---@field model string
+---@field temperature number
+---@field top_p number
+---@field prediction {type: string, content: string}
+---@field n number
+---@field stream boolean
+---@field snippy {enabled: boolean}
+
+---@return Payload
 function Context:payload()
 	-- copy from vscode
 	return {
diff --git a/lua/nes/core.lua b/lua/nes/core.lua
index 3a9a07e..9dd40f8 100644
--- a/lua/nes/core.lua
+++ b/lua/nes/core.lua
@@ -279,6 +279,8 @@ function M.get_suggestion(bufnr)
 	local ctx = Context.new(bufnr)
 	local payload = ctx:payload()
 	require("nes.api").call(payload, function(stdout)
+    -- __AUTO_GENERATED_PRINT_VAR_START__
+    print([==[M.get_suggestion#(anon) stdout:]==], vim.inspect(stdout)) -- __AUTO_GENERATED_PRINT_VAR_END__
 		local next_version = vim.trim(stdout)
 		assert(next_version)
 		if not vim.startswith(next_version, "<next-version>") then
diff --git a/lua/nes/init.lua b/lua/nes/init.lua
index 15610b9..6e813f9 100644
--- a/lua/nes/init.lua
+++ b/lua/nes/init.lua
@@ -1,7 +1,9 @@
 local M = {}
+M.opts = {}
 
 function M.setup(opts)
 	opts = opts or {}
+	M.opts = opts
 
 	vim.api.nvim_set_hl(0, "NesAdd", { link = "DiffAdd", default = true })
 	vim.api.nvim_set_hl(0, "NesDelete", { link = "DiffDelete", default = true })
diff --git a/samplecode.go b/samplecode.go
new file mode 100644
index 0000000..d82bf8f
--- /dev/null
+++ b/samplecode.go
@@ -0,0 +1,39 @@
+package main
+
+import (
+    "flag"
+    "fmt"
+    "math"
+
+    "log/slog"
+)
+
+var Args struct {
+    logLevel string
+}
+
+func init() {
+    flag.StringVar(&Args.logLevel, "log-level", "info", "Set the log level")
+    flag.Parse()
+}
+
+type Point struct {
+    x int
+    y int
+}
+
+func NewPoint(x, y int) Point {
+    return Point{x: x, y: y}
+}
+
+func (p *Point) Distance(other Point) float64 {
+    return math.Sqrt(float64((p.x-other.x)*(p.x-other.x) + (p.y-other.y)*(p.y-other.y)))
+}
+
+func (p *Point) String() string {
+    return fmt.Sprintf("Point(%d, %d)", p.x, p.y)
+}
+
+func main() {
+    slog.Info("Starting application", "logLevel", Args.logLevel)
+}