diff --git a/lua/avante/llm_tools.lua b/lua/avante/llm_tools.lua
index 7757b4f..5d41d09 100644
--- a/lua/avante/llm_tools.lua
+++ b/lua/avante/llm_tools.lua
@@ -1631,6 +1631,57 @@ M._tools = {
       },
     },
   },
+  {
+    name = "read_definitions",
+    description = "Retrieves the complete source code definitions of any symbol (function, type, constant, etc.) from your codebase.",
+    param = {
+      type = "table",
+      fields = {
+        {
+          name = "symbol_name",
+          description = "The name of the symbol to retrieve the definition for",
+          type = "string",
+        },
+        {
+          name = "show_line_numbers",
+          description = "Whether to show line numbers in the definitions",
+          type = "boolean",
+          default = false,
+        },
+      },
+    },
+    returns = {
+      {
+        name = "definitions",
+        description = "The source code definitions of the symbol",
+        type = "string[]",
+      },
+      {
+        name = "error",
+        description = "Error message if the definition retrieval failed",
+        type = "string",
+        optional = true,
+      },
+    },
+    func = function(input_json, on_log, on_complete)
+      local symbol_name = input_json.symbol_name
+      local show_line_numbers = input_json.show_line_numbers
+      if on_log then on_log("symbol_name: " .. vim.inspect(symbol_name)) end
+      if on_log then on_log("show_line_numbers: " .. vim.inspect(show_line_numbers)) end
+      if not symbol_name then return nil, "No symbol name provided" end
+      local sidebar = require("avante").get()
+      if not sidebar then return nil, "No sidebar" end
+      local bufnr = sidebar.code.bufnr
+      if not bufnr then return nil, "No bufnr" end
+      if not vim.api.nvim_buf_is_valid(bufnr) then return nil, "Invalid bufnr" end
+      if on_log then on_log("bufnr: " .. vim.inspect(bufnr)) end
+      Utils.lsp.read_definitions(bufnr, symbol_name, show_line_numbers, function(definitions, error)
+        local encoded_defs = vim.json.encode(definitions)
+        on_complete(encoded_defs, error)
+      end)
+      return nil, nil
+    end,
+  },
 }
 
 ---@param tools AvanteLLMTool[]
diff --git a/lua/avante/types.lua b/lua/avante/types.lua
index 686f88d..d7de584 100644
--- a/lua/avante/types.lua
+++ b/lua/avante/types.lua
@@ -401,3 +401,7 @@ vim.g.avante_login = vim.g.avante_login
 ---@field handler_opts AvanteHandlerOptions
 ---@field on_response_headers? fun(headers: table<string, string>): nil
 ---
+---@class avante.lsp.Definition
+---@field content string
+---@field uri string
+---
diff --git a/lua/avante/utils/init.lua b/lua/avante/utils/init.lua
index da7efbd..4f0ded6 100644
--- a/lua/avante/utils/init.lua
+++ b/lua/avante/utils/init.lua
@@ -8,6 +8,7 @@ local lsp = vim.lsp
 ---@field file avante.utils.file
 ---@field history avante.utils.history
 ---@field environment avante.utils.environment
+---@field lsp avante.utils.lsp
 local M = {}
 
 setmetatable(M, {
@@ -313,18 +314,6 @@ function M.get_hl(name)
   return api.nvim_get_hl(0, { name = name })
 end
 
-M.lsp = {}
-
----@alias vim.lsp.Client.filter {id?: number, bufnr?: number, name?: string, method?: string, filter?:fun(client: vim.lsp.Client):boolean}
-
----@param opts? vim.lsp.Client.filter
----@return vim.lsp.Client[]
-function M.lsp.get_clients(opts)
-  ---@type vim.lsp.Client[]
-  local ret = vim.lsp.get_clients(opts)
-  return (opts and opts.filter) and vim.tbl_filter(opts.filter, ret) or ret
-end
-
 --- vendor from lazy.nvim for early access and override
 
 ---@param path string
diff --git a/lua/avante/utils/lsp.lua b/lua/avante/utils/lsp.lua
new file mode 100644
index 0000000..7703c76
--- /dev/null
+++ b/lua/avante/utils/lsp.lua
@@ -0,0 +1,112 @@
+---@class avante.utils.lsp
+local M = {}
+
+---@alias vim.lsp.Client.filter {id?: number, bufnr?: number, name?: string, method?: string, filter?:fun(client: vim.lsp.Client):boolean}
+
+---@param opts? vim.lsp.Client.filter
+---@return vim.lsp.Client[]
+function M.get_clients(opts)
+  ---@type vim.lsp.Client[]
+  local ret = vim.lsp.get_clients(opts)
+  return (opts and opts.filter) and vim.tbl_filter(opts.filter, ret) or ret
+end
+
+--- return function or variable or class
+local function get_ts_node_parent(node)
+  if not node then return nil end
+  local type = node:type()
+  if
+    type:match("function")
+    or type:match("method")
+    or type:match("variable")
+    or type:match("class")
+    or type:match("type")
+    or type:match("parameter")
+    or type:match("field")
+    or type:match("property")
+    or type:match("enum")
+    or type:match("assignment")
+    or type:match("struct")
+    or type:match("declaration")
+  then
+    return node
+  end
+  return get_ts_node_parent(node:parent())
+end
+
+local function get_full_definition(location)
+  local uri = location.uri
+  local filepath = uri:gsub("^file://", "")
+  local full_lines = vim.fn.readfile(filepath)
+  local buf = vim.api.nvim_create_buf(false, true)
+  vim.api.nvim_buf_set_lines(buf, 0, -1, false, full_lines)
+  local filetype = vim.filetype.match({ filename = filepath, buf = buf }) or ""
+
+  --- use tree-sitter to get the full definition
+  local parser = require("nvim-treesitter.parsers").get_parser(buf, filetype)
+  local tree = parser:parse()[1]
+  local root = tree:root()
+  local node = root:named_descendant_for_range(
+    location.range.start.line,
+    location.range.start.character,
+    location.range.start.line,
+    location.range.start.character
+  )
+  if not node then
+    vim.api.nvim_buf_delete(buf, { force = true })
+    return {}
+  end
+  local parent = get_ts_node_parent(node)
+  if not parent then parent = node end
+  local text = vim.treesitter.get_node_text(parent, buf)
+  vim.api.nvim_buf_delete(buf, { force = true })
+  return vim.split(text, "\n")
+end
+
+---@param bufnr number
+---@param symbol_name string
+---@param show_line_numbers boolean
+---@param on_complete fun(definitions: avante.lsp.Definition[] | nil, error: string | nil)
+function M.read_definitions(bufnr, symbol_name, show_line_numbers, on_complete)
+  local clients = vim.lsp.get_clients({ bufnr = bufnr })
+  if #clients == 0 then
+    on_complete(nil, "No LSP client found")
+    return
+  end
+  local params = { query = symbol_name }
+  vim.lsp.buf_request_all(bufnr, "workspace/symbol", params, function(results)
+    if not results or #results == 0 then
+      on_complete(nil, "No results")
+      return
+    end
+    for _, result in ipairs(results) do
+      if result.error then
+        on_complete(nil, result.error.message)
+        return
+      end
+      local definitions = vim.tbl_filter(function(d) return d.name == symbol_name end, result.result)
+      if #definitions == 0 then
+        on_complete(nil, "No definition found")
+        return
+      end
+      ---@type avante.lsp.Definition[]
+      local res = {}
+      for _, definition in ipairs(definitions) do
+        local lines = get_full_definition(definition.location)
+        if show_line_numbers then
+          local start_line = definition.location.range.start.line
+          local new_lines = {}
+          for i, line_ in ipairs(lines) do
+            table.insert(new_lines, tostring(start_line + i) .. ": " .. line_)
+          end
+          lines = new_lines
+        end
+        local uri = definition.location.uri
+        table.insert(res, { content = table.concat(lines, "\n"), uri = uri })
+      end
+      on_complete(res, nil)
+    end
+  end)
+end
+
+return M