Interactive Mode (REPL)

Interactive mode is the default when you run yoyo in a terminal. It gives you a read-eval-print loop where you can have a multi-turn conversation with the agent.

Starting

yoyo
# or
cargo run

The prompt

The prompt shows your current git branch (if you're in a git repo):

main 🐙 › _

If you're not in a git repo, you get a plain prompt:

🐙 › _

Line editing & history

yoyo uses rustyline for a full readline experience:

Arrow keys: Navigate within the current line (← →) and through command history (↑ ↓)
Inline hints: As you type a slash command, a dimmed suggestion appears after the cursor showing the completion and a short description — e.g. typing /he shows lp — Show help for commands. Press Tab or → to accept.
Tab completion: Type / and press Tab to see available slash commands with descriptions — each command is shown alongside a short summary of what it does. Partial matches work too — /he<Tab> suggests /help and /health. After typing a command + space, argument-aware completions kick in:
- /model <Tab> — suggests known model names (Claude, GPT, Gemini, etc.)
- /provider <Tab> — suggests known provider names (anthropic, openai, google, etc.)
- /think <Tab> — suggests thinking levels (off, minimal, low, medium, high)
- /git <Tab> — suggests git subcommands (status, log, add, diff, branch, stash)
- /pr <Tab> — suggests PR subcommands (list, view, diff, comment, create, checkout)
- /save <Tab> and /load <Tab> — suggest .json session files in the current directory
- File paths also complete — type src/ma<Tab> to get src/main.rs, or Cargo<Tab> to get Cargo.toml. Directories complete with a trailing / for easy continued navigation.
History recall: Previous inputs are saved across sessions
Keyboard shortcuts: Ctrl-A (start of line), Ctrl-E (end of line), Ctrl-K (kill to end), Ctrl-W (delete word back)
History file: Stored at $XDG_DATA_HOME/yoyo/history (defaults to ~/.local/share/yoyo/history)

How it works

You type a message
yoyo sends it to the LLM along with conversation history
The LLM may call tools (read files, run commands, etc.)
Tool results are streamed back — you see each tool as it executes
The final text response is printed
Token usage and cost are shown after each turn

Tool output

When yoyo uses tools, you'll see status indicators:

  ▶ $ cargo test ✓ (2.1s)
  ▶ read src/main.rs ✓ (42ms)
  ▶ edit src/lib.rs ✓ (15ms)
  ▶ $ cargo test ✗ (1.8s)

✓ means the tool succeeded
✗ means the tool returned an error
The duration shows how long the tool took

Token usage

After each response, you'll see a compact token summary:

  ↳ 3.2s · 1523→842 tokens · $0.0234

Use --verbose (or -v) for the full breakdown including session totals and cache info.

This shows:

Wall-clock time for the response
Input→output tokens for this turn
Estimated cost for this turn

Interrupting

Press Ctrl+C to cancel the current response. The agent will stop and you can type a new prompt. Press Ctrl+C again to exit.

Inline @file mentions

You can reference files directly in your prompts using @path syntax. The file content is automatically read and injected into the conversation — no need for a separate /add command.

> explain @src/main.rs
  ✓ added src/main.rs (250 lines)
  (1 file inlined from @mentions)

> refactor @src/cli.rs:50-100
  ✓ added src/cli.rs (lines 50-100) (51 lines)
  (1 file inlined from @mentions)

> compare @Cargo.toml and @README.md
  ✓ added Cargo.toml (35 lines)
  ✓ added README.md (120 lines)
  (2 files inlined from @mentions)

How it works:

@path — injects the entire file
@path:start-end — injects a specific line range
If the path doesn't exist, the @mention is left as-is (it might be a username)
Email-like patterns (user@example.com) are not treated as file mentions
Images work too: @screenshot.png inlines the image into the conversation

yoyo documentation