feat: respect agents.md (#2376)

lua/avante/llm.lua

@@ -5,6 +5,7 @@ local uv = vim.uv
 local curl = require("plenary.curl")
 
 local Utils = require("avante.utils")
+local Prompts = require("avante.utils.prompts")
 local Config = require("avante.config")
 local Path = require("avante.path")
 local Providers = require("avante.providers")
@@ -385,6 +386,9 @@ function M.generate_prompts(opts)
   if opts.tools then tools = vim.list_extend(tools, opts.tools) end
   if opts.prompt_opts and opts.prompt_opts.tools then tools = vim.list_extend(tools, opts.prompt_opts.tools) end
 
+  local agents_rules = Prompts.get_agents_rules_prompt()
+  if agents_rules then system_prompt = system_prompt .. "\n\n" .. agents_rules end
+
   ---@type AvantePromptOptions
   return {
     system_prompt = system_prompt,

lua/avante/utils/prompts.lua

@@ -210,4 +210,27 @@ I've successfully created the requested React component with the following featu
   return system_prompt
 end
 
+--- Get the content of AGENTS.md or CLAUDE.md or OPENCODE.md
+---@return string | nil
+function M.get_agents_rules_prompt()
+  local Utils = require("avante.utils")
+  local project_root = Utils.get_project_root()
+  local file_names = {
+    "AGENTS.md",
+    "CLAUDE.md",
+    "OPENCODE.md",
+    ".cursorrules",
+    ".windsurfrules",
+    Utils.join_paths(".github", "copilot-instructions.md"),
+  }
+  for _, file_name in ipairs(file_names) do
+    local file_path = Utils.join_paths(project_root, file_name)
+    if vim.fn.filereadable(file_path) == 1 then
+      local content = vim.fn.readfile(file_path)
+      if content then return table.concat(content, "\n") end
+    end
+  end
+  return nil
+end
+
 return M