diff --git a/lua/core/keymap.lua b/lua/core/keymap.lua
index 5fc6684..39681c5 100644
--- a/lua/core/keymap.lua
+++ b/lua/core/keymap.lua
@@ -248,7 +248,7 @@ vim.keymap.set("n", "<leader>gc", function()
     require("git.commit").commit()
 end)
 vim.keymap.set("n", "<leader>ga", function()
-    require("git.commit").commit({ amend = true })
+    require("git.commit").commit({ args = { "--amend" } })
 end)
 vim.keymap.set("n", "<leader>gl", function()
     require('git.log_view').open({ max_count = 1000 })
diff --git a/lua/git/cmd.lua b/lua/git/cmd.lua
index 5ca540b..0bab41d 100644
--- a/lua/git/cmd.lua
+++ b/lua/git/cmd.lua
@@ -42,6 +42,95 @@ local function git_cmds()
     return cached_cmds
 end
 
+---@param tok string
+---@return boolean
+local function is_expansion_target(tok)
+    local first = tok:sub(1, 1)
+    if first == "%" or first == "#" then
+        return true
+    end
+    if tok:match("^<%w+>") then
+        return true
+    end
+    if tok == "~" or tok:sub(1, 2) == "~/" then
+        return true
+    end
+    return false
+end
+
+---@param line string
+---@param i integer
+---@param buf string[]
+---@param escapes string?
+---@return integer
+local function parse_quoted(line, i, buf, escapes)
+    local quote = line:sub(i, i)
+    local n = #line
+    i = i + 1
+    while i <= n do
+        local c = line:sub(i, i)
+        if c == quote then
+            return i + 1
+        elseif escapes and c == "\\" and i < n then
+            local nxt = line:sub(i + 1, i + 1)
+            if escapes:find(nxt, 1, true) then
+                table.insert(buf, nxt)
+                i = i + 2
+            else
+                table.insert(buf, c)
+                i = i + 1
+            end
+        else
+            table.insert(buf, c)
+            i = i + 1
+        end
+    end
+    return i
+end
+
+---@param line string
+---@return string[]
+function M.parse_args(line)
+    local args = {}
+    local i, n = 1, #line
+    while i <= n do
+        local c = line:sub(i, i)
+        if c == " " or c == "\t" then
+            i = i + 1
+        else
+            local buf = {}
+            local quoted = false
+            while i <= n do
+                c = line:sub(i, i)
+                if c == " " or c == "\t" then
+                    break
+                elseif c == "\\" and i < n then
+                    table.insert(buf, line:sub(i + 1, i + 1))
+                    i = i + 2
+                elseif c == '"' then
+                    quoted = true
+                    i = parse_quoted(line, i, buf, '"\\$`')
+                elseif c == "'" then
+                    quoted = true
+                    i = parse_quoted(line, i, buf, nil)
+                else
+                    table.insert(buf, c)
+                    i = i + 1
+                end
+            end
+            local tok = table.concat(buf)
+            if not quoted and is_expansion_target(tok) then
+                local expanded = vim.fn.expand(tok) --[[@as string]]
+                if expanded ~= "" then
+                    tok = expanded
+                end
+            end
+            table.insert(args, tok)
+        end
+    end
+    return args
+end
+
 ---@param args string[]
 ---@param start integer
 ---@return string?
@@ -139,18 +228,6 @@ local function run_to_messages(r, args)
     )
 end
 
----@param args string[]
----@param flag string
----@return boolean
-local function has_flag(args, flag)
-    for _, a in ipairs(args) do
-        if a == flag then
-            return true
-        end
-    end
-    return false
-end
-
 ---@param args string[]
 ---@return boolean
 local function has_message(args)
@@ -177,14 +254,13 @@ function M.run(args)
 
     local sub = args[1]
     if sub == "commit" and not has_message(args) then
-        commit.commit({ amend = has_flag(args, "--amend") })
+        commit.commit({ args = vim.list_slice(args, 2) })
         return
     end
 
     if sub == "show" then
-        local arg = first_positional(args, 2)
-        if arg and arg:find(":", 1, true) then
-            object.open(r, arg)
+        if #args == 2 and args[2]:find(":", 1, true) then
+            object.open(r, args[2])
             return
         end
         run_in_split(r, args, { ft = "git", needs_rev = true })
@@ -192,12 +268,9 @@ function M.run(args)
     end
 
     if sub == "cat-file" then
-        if vim.list_contains(args, "-p") then
-            local rev = first_positional(args, 2)
-            if rev then
-                object.open(r, rev)
-                return
-            end
+        if #args == 3 and args[2] == "-p" then
+            object.open(r, args[3])
+            return
         end
         run_in_split(r, args, { ft = "git", needs_rev = true })
         return
diff --git a/lua/git/commit.lua b/lua/git/commit.lua
index 407e80c..2b29cfd 100644
--- a/lua/git/commit.lua
+++ b/lua/git/commit.lua
@@ -4,9 +4,8 @@ local util = require("git.util")
 
 local M = {}
 
----@param opts { amend: boolean? }?
+---@param opts { args: string[]? }?
 function M.commit(opts)
-    local amend = opts and opts.amend or false
     local r = repo.resolve()
     if not r then
         util.error("not in a git repository")
@@ -14,8 +13,8 @@ function M.commit(opts)
     end
 
     local cmd = { "git", "commit" }
-    if amend then
-        table.insert(cmd, "--amend")
+    if opts and opts.args then
+        vim.list_extend(cmd, opts.args)
     end
 
     local proxy_buf, proxy_win
diff --git a/lua/git/init.lua b/lua/git/init.lua
index eed4b28..509705e 100644
--- a/lua/git/init.lua
+++ b/lua/git/init.lua
@@ -137,7 +137,8 @@ function M.init()
     })
 
     vim.api.nvim_create_user_command("G", function(opts)
-        require("git.cmd").run(opts.fargs)
+        local cmd = require("git.cmd")
+        cmd.run(cmd.parse_args(opts.args))
     end, {
         nargs = "*",
         complete = function(...)
diff --git a/test/git/cmd_test.lua b/test/git/cmd_test.lua
new file mode 100644
index 0000000..069389e
--- /dev/null
+++ b/test/git/cmd_test.lua
@@ -0,0 +1,99 @@
+local t = require("test")
+local cmd = require("git.cmd")
+
+t.test("parse_args splits on whitespace", function()
+    t.eq(
+        cmd.parse_args("config user.name value"),
+        { "config", "user.name", "value" }
+    )
+end)
+
+t.test("parse_args preserves spaces inside double quotes", function()
+    t.eq(
+        cmd.parse_args([[config user.name "Oscar Wallberg"]]),
+        { "config", "user.name", "Oscar Wallberg" }
+    )
+end)
+
+t.test("parse_args preserves spaces inside single quotes", function()
+    t.eq(
+        cmd.parse_args([[log --grep='bug fix' --author=Oscar]]),
+        { "log", "--grep=bug fix", "--author=Oscar" }
+    )
+end)
+
+t.test("parse_args handles backslash-escaped space", function()
+    t.eq(cmd.parse_args([[a\ b c]]), { "a b", "c" })
+end)
+
+t.test("parse_args handles escaped quote inside double quotes", function()
+    t.eq(cmd.parse_args([["a\"b" c]]), { 'a"b', "c" })
+end)
+
+t.test(
+    "parse_args treats backslash literally inside single quotes",
+    function()
+        t.eq(cmd.parse_args([['a\b' c]]), { "a\\b", "c" })
+    end
+)
+
+t.test("parse_args concatenates adjacent quoted segments", function()
+    t.eq(cmd.parse_args([[foo"bar"baz]]), { "foobarbaz" })
+end)
+
+t.test("parse_args handles tabs as separators", function()
+    t.eq(cmd.parse_args("a\tb\tc"), { "a", "b", "c" })
+end)
+
+t.test("parse_args returns empty list for empty or whitespace input", function()
+    t.eq(cmd.parse_args(""), {})
+    t.eq(cmd.parse_args("   \t  "), {})
+end)
+
+t.test("parse_args preserves empty quoted token", function()
+    t.eq(cmd.parse_args([[a "" b]]), { "a", "", "b" })
+end)
+
+t.test("parse_args expands %% on unquoted token", function()
+    local buf = vim.api.nvim_create_buf(false, false)
+    t.defer(function()
+        pcall(vim.api.nvim_buf_delete, buf, { force = true })
+    end)
+    vim.api.nvim_buf_set_name(buf, vim.fn.getcwd() .. "/some-file.lua")
+    vim.api.nvim_set_current_buf(buf)
+
+    t.eq(
+        cmd.parse_args("add %"),
+        { "add", vim.fn.getcwd() .. "/some-file.lua" }
+    )
+end)
+
+t.test("parse_args does not expand %% inside double quotes", function()
+    local buf = vim.api.nvim_create_buf(false, false)
+    t.defer(function()
+        pcall(vim.api.nvim_buf_delete, buf, { force = true })
+    end)
+    vim.api.nvim_buf_set_name(buf, vim.fn.getcwd() .. "/some-file.lua")
+    vim.api.nvim_set_current_buf(buf)
+
+    t.eq(cmd.parse_args([[log -- "%"]]), { "log", "--", "%" })
+end)
+
+t.test("parse_args does not expand %% inside single quotes", function()
+    local buf = vim.api.nvim_create_buf(false, false)
+    t.defer(function()
+        pcall(vim.api.nvim_buf_delete, buf, { force = true })
+    end)
+    vim.api.nvim_buf_set_name(buf, vim.fn.getcwd() .. "/some-file.lua")
+    vim.api.nvim_set_current_buf(buf)
+
+    t.eq(cmd.parse_args([[log -- '%']]), { "log", "--", "%" })
+end)
+
+t.test("parse_args does not treat mid-token tilde as expansion", function()
+    t.eq(cmd.parse_args("checkout HEAD~3"), { "checkout", "HEAD~3" })
+end)
+
+t.test("parse_args expands leading ~/ to home", function()
+    t.eq(cmd.parse_args("add ~/foo"), { "add", vim.fn.expand("~/foo") })
+end)