OpenPeon

April 25, 2026 · View on GitHub

An open standard for coding event sounds.

Any agentic IDE or terminal editor can implement the Coding Event Sound Pack Specification (CESP) to give developers audio feedback when tasks complete, errors occur, or input is needed.

Why

Agentic coding tools (Claude Code, Cursor, Windsurf, Copilot) run tasks in the background. You tab away, lose focus, and waste time waiting for something that finished 5 minutes ago. Sound notifications fix this — but every tool reinvents the wheel with its own format.

CESP standardizes the format so sound packs work everywhere. The concept — born in PeonPinginspired Microsoft to add native sound hooks to VS Code for 50M+ users.

The Spec

CESP v1.0 Specification defines:

  • 9 event categories (session.start, task.complete, input.required, etc.) that any IDE maps to
  • Manifest format (openpeon.json) with author info, checksums, licensing
  • Directory structure and audio file constraints
  • IDE mapping contract — each tool maps its own events to CESP categories

Quick Start: Create a Sound Pack

  1. Create a directory with your sounds:
my-pack/
  openpeon.json
  sounds/
    Hello.mp3
    Done.mp3
    Error.mp3
  1. Write a manifest (openpeon.json):
{
  "cesp_version": "1.0",
  "name": "my-pack",
  "display_name": "My Sound Pack",
  "version": "1.0.0",
  "categories": {
    "session.start": {
      "sounds": [
        { "file": "sounds/Hello.mp3", "label": "Hello!" }
      ]
    },
    "task.complete": {
      "sounds": [
        { "file": "sounds/Done.mp3", "label": "All done." }
      ]
    },
    "task.error": {
      "sounds": [
        { "file": "sounds/Error.mp3", "label": "Something went wrong." }
      ]
    }
  }
}
  1. Validate against the schema:
python3 -c "
import json, jsonschema
schema = json.load(open('spec/openpeon.schema.json'))
manifest = json.load(open('my-pack/openpeon.json'))
jsonschema.validate(manifest, schema)
print('Valid!')
"

That's it. Your pack works with any CESP-compatible player.

Integration

Want to add CESP sound pack support to your CLI or coding tool? Copy the contents of INTEGRATE.md into your AI coding agent and let it handle the wiring.

You can also find it rendered at openpeon.com/integrate.

See the full spec for details on sound selection, volume control, and pack management.

Event Categories

Core (players MUST support)

CategoryWhen to play
session.startSession or workspace opens
task.acknowledgeTool accepted work, is processing
task.completeWork finished successfully
task.errorSomething failed
input.requiredBlocked, waiting for user
resource.limitRate/token/quota limit hit

Extended (optional)

CategoryWhen to play
user.spamUser sending commands too fast
session.endSession closes
task.progressLong task still running

Examples

All official packs live in PeonPing/og-packs.

Registry

The OpenPeon registry is live at PeonPing/registry. The registry index is published to peonping.github.io/registry/index.json and currently lists 100+ packs.

Packs are hosted in their own repos. Official packs are in PeonPing/og-packs. Community packs live in contributor repos. See Registry Design for the architecture details.

Implementations

ToolStatusLink
peon-ping (Claude Code, Codex, Cursor, Windsurf, Kiro, Copilot, Gemini CLI, OpenCode, Kilo Code, Antigravity)Reference implementation100+ packs
Claudette (Claude Code Orchestrator)Desktop companion GUI
Your CLI hereIntegration guide

Website

The openpeon.com website lets you browse all registered packs with audio previews, filterable by tag, language, and trust tier (official/community). It also includes an integration guide for adding CESP support to any CLI. Source is in site/.

Files

spec/
  cesp-v1.md                   # The specification
  openpeon.schema.json          # JSON Schema for manifests
  registry-entry.schema.json    # JSON Schema for registry entries
examples/                        # Example sound packs (peon, glados)
scripts/
  generate-registry.ts          # Registry generation script
site/                            # The openpeon.com website
docs/
  registry-design.md            # Registry architecture blueprint
tests/                           # Schema validation tests
CLAUDE.md                        # Project documentation for AI assistants
CONTRIBUTING.md                  # Contribution guide

License

MIT