- name
- message-injector
- description
- OpenClaw plugin that prepends custom text to every user message before it reaches the agent. Use for: enforcing memory_search before replies, injecting system-level instructions, adding persistent reminders to every conversation turn. Install as a workspace extension — works on all channels including WebChat, Telegram, Slack, etc.
Message Injector
A lightweight OpenClaw workspace extension that uses the before_agent_start hook to inject custom text into every user message via prependContext.
Installation
1. Create the extension directory
mkdir -p ~/.openclaw/workspace/.openclaw/extensions/message-injector2. Copy the plugin files
Copy scripts/index.ts and scripts/openclaw.plugin.json to the extension directory:
cp scripts/index.ts ~/.openclaw/workspace/.openclaw/extensions/message-injector/
cp scripts/openclaw.plugin.json ~/.openclaw/workspace/.openclaw/extensions/message-injector/3. Add configuration
Add the following to ~/.openclaw/openclaw.json under plugins.entries:
"message-injector": {
"enabled": true,
"config": {
"enabled": true,
"prependText": "Your custom text here"
}
}4. Restart Gateway
openclaw gateway restartConfiguration
| Field | Type | Default | Description |
|---|---|---|---|
enabled | boolean | true | Enable or disable the injector |
prependText | string | "" | Text to prepend before every user message |
Example Use Cases
Force memory search:
"prependText": "[⚠️ 回答前必须先 memory_search 检索相关记忆，禁止凭印象回答]"Add persistent context:
"prependText": "[当前项目：my-app | 技术栈：React + Node.js | 部署环境：AWS]"Inject safety rules:
"prependText": "[RULE: Always verify file paths before deletion. Never run rm -rf without confirmation.]"How It Works
The plugin registers a before_agent_start hook. When triggered, it returns { prependContext: prependText } which OpenClaw prepends to the user's message before the agent processes it. This is a hard injection at the Gateway level — the agent cannot skip or ignore it.
Source Code
GitHub: https://github.com/Harukaon/openclaw-message-injector