Panes
A layout you can read, edit, and reload. Keep the prompt and safety controls in trusted terminal chrome.
/pane
/pane focus
/pane edit
/pane generate a compact swarm viewxcb / Excalibur
Your agents. Your terminal. Your edge.
xcb (Excalibur) is a local, terminal-first workspace for coding agents. Bring your accounts, choose your models, and shape the interface around your work. Small, composable extensions handle usage, continuation, and context management; the kernel keeps sessions, credentials, and execution under explicit custody.
Excalibur, for short. Local-first and MIT licensed. Native Rust interface in development; the AgentMixer compatibility package remains available.
xcb · factory / renderer usage: unmeasured
You
Make the interface feel like mine.
▸ Thinking collapsed
▸ Earlier responses collapsed
The pane is a declaration, not a fork of the harness.
Edit it here. Keep working. See it reload.
Subagents renderer: working · tests: complete
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› /pane focus
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Claude · Fable 5.1 [ working ]A small core. The parts you choose.
The native direction: accounts and sessions in the kernel, behavior in extensions, presentation in userspace. No cloud control plane required.
Bring your accounts
Keep named coding-agent accounts together without mixing their credentials. See subscription windows and usage freshness in one compact view.
Choose your models
Favorites first, the rest below. Pick a model across harnesses, or a provider-managed mode such as Devin Adaptive or Fusion. No task-shape router making the choice for you.
Make it your pane
Choose, edit, or generate a userspace pane with /pane. Reload a valid change without rebuilding the terminal; an invalid edit keeps the last working view.
See the pace
Session token velocity, a share of observed local throughput, and subscription runway estimates. Unknown quota stays unknown, not a reassuring full meter.
Keep context useful
Gobstopper supplies the context-management strategy. Apply supported compaction at settled boundaries, with the full local transcript retained.
Compose the behavior
Continuation, usage, and context management are separate extensions. Add trusted lifecycle hooks without turning the renderer into the execution kernel.
Shape the harness from inside it.
These are the native interface's design targets. See the docs for the current implementation and provider qualification limits.
Models
Choose a fixed favorite or a provider-managed mode. Fusion pairings stay pairings, not invented capability scores.
Devin SWE-2 · Astra Max · Sol Max
Modes Adaptive · Fusion
Claude Fable 5.1 · Opus 5
Codex Astra Ultra · Sol UltraExtensions
Useful defaults, individually switchable. Publishing and executable hooks need their own explicit opt-in.
auto-continue on · bounded
gobstopper on · safe boundaries
usage local
aiCharts upload offMalleable, without being fragile.
Make the interface personal. Keep the important boundaries explicit.
The kernel keeps custody.
A prompt is not isolation. A timeout is not proof that a process stopped. A fresh view is not permission to repeat a mutation.
- Local by default
- Accounts, session history, configuration, and panes stay on this machine. No cloud synchronization or required daemon. aiCharts publishing is a separate opt-in, not a condition of local measurement.
- Continue, not blindly repeat
- Automatic continuation stops for questions, authentication, approvals, cancellation, and budget limits. A quota failure can trigger a settled handoff; an uncertain effect cannot authorize replay.
- A pane is not permission
- Pane declarations are bounded presentation data. Generating a view cannot grant credential access, execute a hook, or change provider admission. Executable extensions require a separate trust decision.
Start with the source.
Native xcb is in development. The source tree keeps the Rust work separate from the published TypeScript compatibility package.
Follow the native work · Read the native interface guide
AgentMixer compatibility package
Current verified compatibility release · v0.3.0
bun add https://github.com/hraness/xcb/releases/download/v0.3.0/hraness-agentmixer-0.3.0.tgzPublic release verification. This installs @hraness/agentmixer, not a native xcb release. Compatibility package reference.
Before you start.
What is xcb?
xcb is Excalibur: a local, terminal-first workspace for coding agents. It is AgentMixer's new name and direction, with a native Rust kernel and a composable terminal interface in development.
Is this Oompa in a terminal?
No. xcb carries forward useful ideas about accounts, usage, response state, and handoffs without Oompa's cloud control plane. The core is local; optional extensions add behavior.
Can I use Adaptive and Fusion?
The model catalog distinguishes fixed models, Adaptive routing, and Fusion lead/sidekick pairings. Choices must come from the provider's observed catalog; availability in a catalog is not itself proof that a native execution adapter is qualified.
Does usage go to aiCharts automatically?
No. Local measurement and publishing are separate. The design supports opt-in idle-boundary exports using aiCharts formats; its upload service is not yet live-qualified. Session text and credentials are not numeric usage data.
What can I install today?
The AgentMixer 0.3.0 TypeScript package remains the verified compatibility release. Native xcb is being developed separately. An old package release is not advertised as a native xcb binary.
Who made it?
Ben Guo, a musician and builder, formerly a founder and engineering leader at companies including Venmo and Stripe, now building from Puerto Rico. xcb is published by Hraness under the MIT license.
Built by Ben Guo
xcb is built by Ben Guo, a musician and builder, formerly a founder and engineering leader at companies including Venmo and Stripe, now building from Puerto Rico. Published by Hraness under the MIT license.
An edge of your own.
Keep the accounts. Choose the models. Make the terminal yours.
Excalibur, for short. Local-first and MIT licensed. Native Rust interface in development; the AgentMixer compatibility package remains available.