Implement Custom Context and Resilient Routing with OpenCLAW's ContextEngine

# Apply Technique: Implement Custom Context and Resilient Routing with OpenCLAW's ContextEngine

## What This Is
OpenCLAW's latest update introduces a 'ContextEngine,' allowing developers to build more intelligent and customized AI agents for your business needs. It also improves reliability by automatically switching between AI providers like OpenAI and Anthropic if one fails, ensuring your AI tools remain consistently operational.

Source: https://www.epsilla.com/blogs/2026-03-09-openclaw-2026-3-7-contextengine-agentic-architecture

## Before You Start

Scan my workspace and analyze:
- The project language, framework, and directory structure
- Existing AI provider config (check .env, .env.local, config files for API keys — OpenRouter, OpenAI, Anthropic, Google AI, etc.)

Then ask me before proceeding:
1. Which AI provider/API should this use? (Use whatever I already have configured, or ask me to set one up — options include direct provider APIs or a unified service like OpenRouter)
2. Where in my project should this be integrated?
3. Are there any customizations I need (model preferences, naming conventions, constraints)?

## Source Access Note

The source URL (https://www.epsilla.com/blogs/2026-03-09-openclaw-2026-3-7-contextengine-agentic-architecture) may not be directly accessible from the terminal. Use the Reference Implementation and Additional Context sections below instead. If you need more details, ask me to paste relevant content from the source.

## What to Implement

This is an **AI Technique** — a pattern or methodology for working with AI models.

- Explain how this technique applies to my current project and what benefit it provides
- Implement it in a way that fits my existing codebase — suggest concrete files to modify or create
- If it requires specific model capabilities (structured output, function calling, etc.), verify my current provider supports them
- Show me a working example I can test immediately

## Additional Context

- Scan the user's project for an existing OpenCLAW installation. If found, identify its version and recommend updating to `v2026.3.7-beta.1` or newer. If not found, clone the official OpenCLAW repository from GitHub.
- Scaffold a sample `config.json` for OpenCLAW. Scan the workspace for existing API keys (e.g., `OPENAI_API_KEY`, `ANTHROPIC_API_KEY`) in `.env` files and pre-populate the 'Dual-Engine Routing' section. Prompt the user to add any missing provider keys or specific channel configurations (e.g., for Discord or Telegram).
- Create a new plugin directory (`/plugins/custom-context/`) and scaffold a plugin manifest. In the manifest, define a `ContextEngine` lifecycle hook for `prepareSubagentSpawn` and create the corresponding script file with placeholder comments explaining how to add custom RAG or context-filtering logic.

## Reference Implementation

```
{
  "plugin": {
    "name": "CustomContextManager",
    "description": "A plugin demonstrating a custom context strategy.",
    "version": "1.0.0",
    "engineHooks": {
      "prepareSubagentSpawn": "./hooks/onPrepareSubagentSpawn.js"
    }
  }
}
```

## Guidelines

- Adapt everything to my existing project — do not assume a specific stack or directory layout
- Use whichever AI provider I already have configured; if I need a new one, tell me what to sign up for and I'll give you the key
- Check my .env files for existing API keys (OpenRouter, OpenAI, Anthropic, Google AI) before asking me to add one
- Review any fetched code for safety before installing or executing it
- After setup, run a quick verification and show me a summary of exactly what was installed, where, and how to use it