Build the whole cycle.
From your terminal.
The AI coding agent for product engineers — discover, build, verify and ship, on any model, in any terminal. Local-first, safe by default, no account.
The m-shell
Not commands. A conversation.
Run excalibur and just say what you want. It routes intent to the right workflow, shows you the plan, and works in the open — with a live TUI you can read.
- Plain language or /commands — it routes intent to the right workflow.
- Inline approvals: y · N · always, respecting standard-safe.
- ↑/↓ history, @file and #symbol references, resumable sessions.
- Watch it think, edit and test live — one event stream, one source of truth.
Dial it from a question to a full agentic run
Express intent — Excalibur picks the workflow and sizes the work. You decide how far it goes, per task.
reviewaskpatchrunrun --carefulThe whole cycle — on your machine
Discovery, a local backlog, runs, replay and a web dashboard — your fleet of agents, no cloud, no account.
Local web dashboard
A lazy daemon serves a fleet view of every run — diffs, tests, cost — at localhost.
Work items & kanban
A local backlog and board — no Linear, no Jira, no cloud required.
Time machine
Rewind any run and fork from any point — only what changed re-runs.
Self-sizing swarm
Big tasks fan out to parallel agents in isolated worktrees — sized for you.
Memory that compounds
Decisions accumulate in .excalibur/memory — every run gets sharper.
Discovery gate
Clarify scope first — and decide whether to build it at all.
Fits your setup
Keep what you already have
Excalibur detects and respects your existing instructions — no rewrites. It asks before enabling anything executable.
CLAUDE.mdrespectedAGENTS.mdrespectedCursor rulesrespectedCopilot instructionsrespectedREADME · docs · ADRsrespectedSKILL.mdreview first
Extend everything
YAML, the SDK, MCP & LSP
Shape how your team works with simple YAML — or go deeper with the TypeScript SDK. External tools and real compiler errors flow straight to the agent.
YAML / Markdown
Workflows, methodologies, prompts, safety presets, model routing.
TypeScript SDK
On npm — work-item providers, channels, model adapters, tools, policies.
Custom agents
Self-contained Markdown personas — role, model, tools and permissions per agent.
MCP servers
External tools enter the agent with the manifest’s permissions.
LSP diagnostics
Real compiler errors anchor fixes — no hallucinated lines.
IDE extension
VS Code, Cursor and Windsurf bridge to the agent over ACP.
Runs anywhere you do — any terminal or IDE (JetBrains, Cursor, VS Code, SSH, CI), on macOS, Linux and Windows.
portable by designSafe by default
Delegate big work without fear
Nothing is modified, applied or pushed without your explicit approval. standard-safe is on from the first command.
Approval gates
Every write, command and push pauses for an explicit yes.
Sandboxed execution
Agents run isolated — no network access by default.
Secrets never leak
.env files and keys are blocked, never read or sent.
Isolated branches
Work lands in dedicated branches — never your tree.