Excalibur CLI

Local-first, AI-assisted and agentic software development from your terminal.

🟡 Public Beta — in active daily use and stable enough to build with; some APIs/config may still change before 1.0-GA. Feedback welcome.

Excalibur Core is an open-source developer toolkit for AI-assisted and agentic coding. It runs entirely on your machine, keeps every artifact in a portable .excalibur/ directory, and never sends your code anywhere you didn't configure.

Part of Excalibur Core (Apache-2.0).

Install

npm install -g @excalibur-oss/excalibur

A single, self-contained binary — no extra setup, no peer dependencies to resolve.

Requires Node.js 22 or newer.

Quickstart — two commands

npm install -g @excalibur-oss/excalibur
cd your-project && excalibur

That's the whole setup. On the first run in a repo, Excalibur sets itself up for you — detects your stack, helps you connect a model (your API key or a subscription), writes a minimal .excalibur/ — then drops you into the interactive shell. You never have to discover init or models setup.

In the shell, just say what you want in plain language; Excalibur picks the right action and autonomy level for you:

▸ where is escrow release implemented?
▸ add an idempotency guard to the webhook handler
▸ /rewind                                    # scrub a run, fork from any step
▸ /swarm refactor the billing module + tests # parallel agents in worktrees

Prefer one-shot subcommands? They all work too:

excalibur ask "Where is escrow release implemented?"
excalibur run "Add an idempotency guard to the webhook handler" --fast
excalibur status && excalibur logs

excalibur init is optional — only for explicit --team / --full scaffolding or CI. You never need it to get value.

What you can do

| Command | What it does | | ------------------------------------------ | --------------------------------------------------------------------- | | excalibur | The interactive shell — describe what you want; onboards on first run | | excalibur run "…" | Run an agentic workflow phase by phase (autonomy L3/L4) | | excalibur swarm "…" | Fan out independent subtasks as parallel agents in git worktrees | | excalibur explore "…" | Best-of-N — run N candidate approaches in parallel, keep the winner | | excalibur orchestrate · orchestration | Re-run/resume a parallel run · watch its live wave/DAG chronogram | | excalibur schedule add "…" "…" | Autonomous scheduled jobs (every N / daily at) | | excalibur ask "…" / explain | Ask questions about the repo (L1) | | excalibur review [--diff] | Review working changes (L0) | | excalibur patch "…" → apply / branch | Propose a diff, then apply it (L2) | | excalibur rewind | Time machine — step a run, fork or undo from any step | | excalibur verify | Adversarial Verification Mesh over a run's changes | | excalibur serve | Read-only web dashboard (runs / events / insights) over local HTTP | | excalibur insights | Cross-run cost / token / outcome lens | | excalibur discovery "<idea>" | Decide whether to build — deterministic scoring | | excalibur work-items | GitHub Issues as agent-native work items (via the gh CLI) | | excalibur mcp · theme · doctor | Inspect MCP servers · switch TUI theme · diagnose your setup |

Run excalibur <command> --help for the full set of flags. Autonomy levels (0–4), workflows, model routing and tool permissions all live in .excalibur/config.yaml.

Models — bring your own

Excalibur is model-agnostic and BYOK (bring your own key): your API keys are read from environment variables and never written to .excalibur/. First-run onboarding connects one for you; to switch or add providers later:

excalibur models setup     # API key or subscription · auto-pairs a fast model
excalibur models list

One key configures a curated good + fast model pair (the fast model powers ghost-text suggestions and context compaction). A deterministic offline mock provider is the zero-config default until you connect a real model.

Links

• Repository: https://github.com/ExcaliburOSS/excalibur-core
• Issues: https://github.com/ExcaliburOSS/excalibur-core/issues
• License: Apache-2.0