How do I install the Core Runtime skill?

Run npx skillmds@latest add open-wa/core-runtime in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is Core Runtime safe to use?

This skill has not completed SkillMD's automated safety review yet. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Core Runtime?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Core Runtime free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published Core Runtime?

open-wa (@open-wa) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Core Runtime by open-wa — Agent Skill

Name: Core Runtime
Author: open-wa

File contents

Core Runtime Skill

This skill teaches AI agents how to interact with an open-wa WhatsApp session correctly and safely.

Session Lifecycle

An open-wa session goes through the following states:

INITIALIZING — The browser is launching and loading WhatsApp Web.
QR_READY — A QR code is available for scanning (first-time auth).
AUTHENTICATED — The QR was scanned or the session restored from cache.
READY — The session is fully connected and all tools are available.
DISCONNECTED — The session lost its connection and may be recovering.

Readiness Rules

Never call tools before the session is READY. Check /health or poll the session state first.
If the session is in QR_READY, the agent should inform the user that a QR code needs to be scanned.
If the session is DISCONNECTED, wait for automatic reconnection before retrying.

Authentication Flows

QR Code Auth (first-time)

Start the runtime.
A QR code appears at /qr or in the launch timeline.
The user scans it in WhatsApp on their phone.
The session transitions to AUTHENTICATED → READY.

Session Restore (subsequent starts)

If userDataDir was configured, the browser reuses cached credentials.
The session transitions directly to READY without a QR code.
If the cache is stale, the runtime falls back to QR auth.

Message Safety

Rate limiting: WhatsApp enforces anti-spam measures. Do not send messages in rapid bursts. Space sends by at least 1-2 seconds.
Content: Never send unsolicited messages to users who have not opted in. This risks account bans.
Groups: Be cautious with group operations. Adding/removing members affects real users.

License-Gated Features

Some open-wa methods require a license key. If a tool call returns a license error, inform the user that the feature requires a license upgrade. Do not retry.

Error Handling

Validation errors (400): Fix the tool arguments and retry.
Session not ready (503): Wait and check /health before retrying.
Internal errors (500): Report the error to the user. Do not auto-retry more than once.

---name: core-runtimedescription: Teaches AI agents about open-wa session lifecycle, readiness expectations, and safe operation patterns.---# Core Runtime SkillThis skill teaches AI agents how to interact with an open-wa WhatsApp session correctly and safely.## Session LifecycleAn open-wa session goes through the following states:1. **INITIALIZING** — The browser is launching and loading WhatsApp Web.2. **QR_READY** — A QR code is available for scanning (first-time auth).3. **AUTHENTICATED** — The QR was scanned or the session restored from cache.4. **READY** — The session is fully connected and all tools are available.5. **DISCONNECTED** — The session lost its connection and may be recovering.## Readiness Rules- **Never call tools before the session is READY.** Check `/health` or poll the session state first.- If the session is in `QR_READY`, the agent should inform the user that a QR code needs to be scanned.- If the session is `DISCONNECTED`, wait for automatic reconnection before retrying.## Authentication Flows### QR Code Auth (first-time)1. Start the runtime.2. A QR code appears at `/qr` or in the launch timeline.3. The user scans it in WhatsApp on their phone.4. The session transitions to `AUTHENTICATED` → `READY`.### Session Restore (subsequent starts)1. If `userDataDir` was configured, the browser reuses cached credentials.2. The session transitions directly to `READY` without a QR code.3. If the cache is stale, the runtime falls back to QR auth.## Message Safety- **Rate limiting**: WhatsApp enforces anti-spam measures. Do not send messages in rapid bursts. Space sends by at least 1-2 seconds.- **Content**: Never send unsolicited messages to users who have not opted in. This risks account bans.- **Groups**: Be cautious with group operations. Adding/removing members affects real users.## License-Gated FeaturesSome open-wa methods require a license key. If a tool call returns a license error, inform the user that the feature requires a license upgrade. Do not retry.## Error Handling- **Validation errors (400)**: Fix the tool arguments and retry.- **Session not ready (503)**: Wait and check `/health` before retrying.- **Internal errors (500)**: Report the error to the user. Do not auto-retry more than once.

Frequently asked questions

Core Runtime