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README.md

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+# tsm — ultra-light tmux session manager (Go 1.24)
+
+Features:
+- Live built-in fuzzy filter UI (no external `fzf`)
+- Scans Git repos concurrently (one goroutine per `scan_paths` root)
+- **Max depth 3** by default
+- Session name from folder + parent: `/Code/ivuorinen/a` → `ivuorinen_a`
+- Existing tmux sessions listed and selectable
+- Bookmarked folders always shown
+- XDG config, no macOS `Library` default
+
+## Install
+
+```shell
+go install github.com/ivuorinen/tsm@latest
+```
+
+## Usage
+
+- Run `tsm` → live filter list opens. Type to filter, navigate with keys below, Enter to select.
+- Selecting a session switches to it. Selecting a repo/bookmark creates (or reuses) a session and switches/attaches.
+
+### Keybindings
+
+| Key            | Action                                  |
+|----------------|-----------------------------------------|
+| ↑ / Ctrl-P     | Move up                                 |
+| ↓ / Ctrl-N     | Move down                               |
+| **Home**       | Jump to first item                      |
+| **End**        | Jump to last item                       |
+| **PgUp**       | Move up 5 items                         |
+| **PgDn**       | Move down 5 items                       |
+| **Backspace**  | Delete one character from query         |
+| **Ctrl-U**     | Clear query                             |
+| **Tab**        | Toggle preview (path + planned action)  |
+| **Enter**      | Select                                  |
+| **Ctrl-C**     | Cancel                                  |
+
+### tmux key binding (popup)
+
+```text
+bind-key t display-popup -E 'tsm' -w 90% -h 80%
+```
+
+## Config
+
+XDG-only:
+- `$XDG_CONFIG_HOME/tsm/config.yaml` or fallback `$HOME/.config/tsm/config.yaml`
+
+Create a default config:
+
+```bash
+tsm -init-config
+```
+
+Example:
+
+```yaml
+scan_paths:
+  - "$HOME/Code"
+bookmarks:
+  - "$HOME"
+exclude_dirs:
+  - ".git"
+  - "node_modules"
+  - "vendor"
+  - "dist"
+  - "build"
+  - "target"
+  - "out"
+  - "bin"
+  - ".cache"
+  - ".next"
+  - ".nuxt"
+  - ".pnpm-store"
+  - ".yarn"
+  - ".yarn/cache"
+  - ".venv"
+  - ".direnv"
+  - "deps"
+  - "_build"
+  - ".terraform"
+  - ".terragrunt-cache"
+  - ".m2"
+  - ".gradle"
+  - "Pods"
+  - "Carthage"
+max_depth: 3
+```
+
+## Flags
+
+- `-config PATH` : set explicit config file path
+- `-print`       : print candidate list (Kind, Name, Path) and exit
+- `-init-config` : write default config to XDG path and exit
+
+## Tests
+
+```bash
+go test ./...
+```
+
+Tests mock tmux and validate name derivation,
+fuzzy ranking, scanning (depth/excludes),
+and tmux command flow.