Supported AI Tools

Lacy works with any AI CLI that accepts a query argument. All tools handle their own authentication — no API keys are needed from Lacy.

Available tools

Tool	Command	Prompt flag	Notes
lash	`lash run -c "query"`	`-c`	Recommended. Preheating support.
claude	`claude -p "query"`	`-p`	Claude Code. Session reuse via `--resume`.
opencode	`opencode run -c "query"`	`-c`	Preheating support.
gemini	`gemini --resume -p "query"`	`-p`	Google Gemini.
codex	`codex exec resume --last "query"`	positional	OpenAI Codex CLI.
hermes	`hermes chat -q "query"`	`-q`	Local/open-source models.
custom	user-defined	user-defined	Any CLI tool.

Selecting a tool

bash

tool              # show active tool + available tools
tool set lash     # set active tool
tool set claude
tool set gemini

The active tool persists to ~/.lacy/config.yaml.

Auto-detection

When agent_tools.active is empty in config, Lacy auto-detects the first installed tool in this priority order: lash → claude → opencode → gemini → codex → hermes.

If no tool is detected on first run, Lacy prompts to install lash.

Custom tool

bash

tool set custom "my-ai-tool --flag"
# or in config.yaml:
# agent_tools:
#   active: custom
#   custom_command: "my-ai-tool --flag"

Lacy appends the user query as the last argument. Your command should accept the query as its final positional argument.

Preheating

lash and opencode support preheating — a background server that stays warm between queries, eliminating cold-start latency.

yaml

# ~/.lacy/config.yaml
# preheat:
#   eager: false        # Start background server on plugin load
#   server_port: 4096   # Port for background server

Claude uses --resume SESSION_ID for conversation continuity instead of a background server. Other tools have no preheating.

lash (recommended)

lash is an opencode fork built by the same author as Lacy. It's the recommended default for the best integration experience, including preheating, session management, and tight context passing.

bash

# Install lash
curl -fsSL https://lash.lacy.sh/install | bash

Tip

During Lacy installation, if no AI tool is detected, you'll be prompted to install lash automatically.