Context. Constraint. Contracts.

Clamp your Claws

Bands are skills with function-like closures and contracts, executed in locked-down microvms.

Agents see only simple CLI commands, with input and output types defined by JSON schemas.

allow: Bash(git *)Anything not allowed is denied. deny: Bash(git push --force *)Deny punches holes in allow. insist: Read(CHANGELOG.md)Forces the skill to use a capability. max_turns: 10Limit turns, tokens, cost, bytes, and more. env: DEPLOY_TOKENOnly expose the minimal necessary environment. contract: deploy_result.schema.jsonAgent sends and receives typed objects.

01 Why Bands

Prompts are programs.
Skills are functions.

There's a reason we don't code by mutating global state variables anymore. Your agent shouldn't work that way, either.

Most skills pollute agent context with implementation details and execution artifacts. They waste tokens, demand excess reasoning, and increase attack surface.

Bands refactor skills as simple CLI commands, each performing a single strongly-typed function.

The Bands System

SKILL.md succinctly tells the agent what CLI commands commands are available and what function they perform. This is compatible with Agent Skills.

BAND.md exhaustively defines the capabilities of the container within which the banded skill will execute. The agent doesn't read this; it's enforced programatically by the band command.

bandcommands wraps every CLI command in a lightweight microvm that enforces all constrains and contracts defined in BAND.md.

agent invocation
$ ./scripts/voice-list
[{"voice_id":"pNInz6obpgDQGcFmaJgB","name":"Adam"}, ...]

$ ./scripts/tts --voice_id pNInz6obpgDQGcFmaJgB --text "You clamped my claws."

skill.md
---
name: elevenlabs
description: ElevenLabs text-to-speech
allowed-tools: Bash(./scripts/*)
---

# ElevenLabs

Generate speech from text using the ElevenLabs REST API.

Run any command with --help to see arguments and schemas.

### Text-to-Speech
- tts — Generate speech from text
  Input: voice_id, text, model_id,
         output_path, stability

### Voices
- voice-list — List available voices
- voice-get — Get voice details
  Input: voice_id

### Sound Effects
- sfx — Generate sound effect from text
  Input: text, duration_seconds, output_path

### Account
- user-info — Get user info and subscription

band.md
---
band: elevenlabs
icon: 🔊
description: Text-to-speech via ElevenLabs API

allow:
  cli:
    - curl -s *
    - jq *
  net:
    - api.elevenlabs.io

deny:
  cli:
    - curl * -X DELETE *
    - curl * --upload-file *

env:
  secrets:
    - ELEVENLABS_API_KEY

limit:
  maxCostDollars: 0.25

contract:
  input:  ./schemas/tts-input.json
  output: ./schemas/tts-output.json

execution:
  target: local-lima
---

Clamp your Claws

Prompts are programs.
Skills are functions.

The Bands System

Execution targets

Lima

Cloudflare

Pre-alpha concept code

Clamp your Claws

Prompts are programs. Skills are functions.

The Bands System

Execution targets

Lima

Cloudflare

Pre-alpha concept code

Prompts are programs.
Skills are functions.