Agent mode

In agent mode the chat model works in your workspace before it answers: it finds and reads files, searches them, asks the language servers about the code, edits files and runs commands such as tests and builds. Each step shows in the reply at the point it ran, so the reply reads in order: what the model said, the tool it used, what it said next.

Agent mode is experimental. It needs a capable coder model, such as qwen3-coder:30b, loaded with a context of 8k tokens or more. Small models tend to call tools badly.

Turning it on

Click the switch at the bottom left of the chat’s composer, or press Shift+Tab in the composer. While it is on, the prompt turns to a bright ❯❯, and it pulses while the model works.

The choice is kept for every window. Until you first switch it, the twinny.chatTools setting decides; it is off by default. The setting is read from your user settings only: a workspace cannot turn agent mode on.

Agent mode needs a folder open. With several folders in the workspace, the tools work in the first.

What the model can do

Tool	What it does
list_dir, find_files	List a directory; find files by glob
read_file	Read a file’s numbered lines, a range at a time in long files
grep	Search the workspace by regular expression
search_code	Find code by what it does, through the workspace index, when you have built one
find_symbol	Find where a function, class, type or variable is defined
git	Read-only git: status, diff, log, show, blame, branch (listing), shortlog, ls-files, rev-parse
diagnostics	The errors and warnings the language servers report
find_references, go_to_definition	Ask the language server where a symbol is used or defined
rename_symbol	Rename a symbol everywhere through the language server
editor_context	The active file, the cursor line, the selection and the other open files
edit_file, create_file	Change a file by replacing text in it; create a new one
move_file, delete_file	Move, rename or delete a file
run_command	Run a shell command from the workspace root and read its exit code and output

A reply takes at most 12 steps; then the model is asked for its answer.

What it may not touch

• Files ignored by a .gitignore, .git, node_modules and files matching twinny.embeddingIgnoredGlobs are off limits to every tool, git and search_code included.
• Changes to .vscode/ or a .gitignore are always shown for review, whatever the settings say.
• Deleting a file git has no copy of always asks first.
• Reading git never asks: the git tool runs only commands that change nothing.

Edits

By default (twinny.chatToolsEdits set to apply) edits go straight into the file and are saved, and the model carries on until the task is done. Ctrl+Z in the file undoes an edit.

Set it to review and each edit opens as a diff to accept or reject, the same as an inline edit; the model stops until you have decided. Renames, moves and deletes ask in the chat.

Commands

twinny.chatToolsCommands decides whether the model may run commands:

Value	Behaviour
ask (default)	Each command is shown in the chat with Run, Always run and Skip
allow	Commands run straight away. A command cannot be undone the way an edit can
off	The model cannot run commands

Always run runs the command and remembers that exact command, so the model can run it again without asking; any other command still asks. Twinny - Forget commands set to always run clears the list.

Auto-run

With agent mode on, an auto-run switch sits next to the agent switch. On, every command runs without asking. Until you first flip it, twinny.chatToolsCommands decides where it starts; once flipped, the switch decides. off still turns commands off.

Approving from the keyboard

When a command or change is waiting and the composer is empty:

Key	Action
Enter	Run the command, or apply the change
Shift+Enter	Always run that command
Esc	Skip it. A second Esc stops the reply

Where commands run

By default (twinny.chatToolsCommandsRunIn set to background) each command runs in a process of its own, from the workspace root, through bash where there is one (your shell otherwise). Its output appears in its step as it prints. Nothing can answer a prompt, and a command is stopped after two minutes, so interactive commands, servers and watch modes belong in a terminal of your own. The model sees the exit code and the end of the output.

A running command has a stop button on its line. It ends that command and anything it started; the model gets the output so far, is told you stopped it, and carries on.

Set twinny.chatToolsCommandsRunIn to terminal to run commands in the twinny tools terminal beside the editor, where you can watch and type into them. That needs VS Code’s shell integration; without it, commands run in the background.

Models and providers

Tools go to the server through its own tool calling where it has one: Ollama, LM Studio, llama.cpp, LiteLLM, Open WebUI and other OpenAI-compatible servers, a paired device, OpenAI, a team gateway, and hosted APIs that take tools (Anthropic, Gemini, Mistral, Groq, OpenRouter and others). When a server or model refuses them, the model is asked to write its calls in the reply instead, which works through anything that carries chat; the Twinny output channel says when that happens. QVAC, text-generation-webui and hosted APIs without tool calling (Perplexity, for one) get calls written in the reply from the start.

Each tool result is held to a share of the model’s context, and when a request would not fit, the oldest results are trimmed first. With a context under about 8k tokens they are trimmed often and the model loses track; the output channel warns you. Raise the server’s context length if you can (for Ollama, see Context size).

Tool results go through the secret shield like the rest of the conversation.

Settings

Setting	Default	Description
twinny.chatTools	false	Where the agent switch starts, until you first switch it
twinny.chatToolsEdits	apply	apply writes edits straight away; review opens each as a diff
twinny.chatToolsCommands	ask	ask, allow or off; where the auto-run switch starts
twinny.chatToolsCommandsRunIn	background	background runs commands in a process of their own; terminal in the twinny tools terminal

All four are machine settings: set them in your user settings.