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docs/en-US/plugin-development.md

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+# Plugin Development
+
+[中文](../zh-CN/plugin-development.md)
+
+Plugins can integrate with CyberStrikeAI through HTTP APIs, MCP servers, or resource packs such as tools, roles, Skills, and agents.
+
+## Plugin Layers
+
+| Layer | Example | Benefit | Cost |
+| --- | --- | --- | --- |
+| API plugin | Burp extension calls `/api/eino-agent` | simple UI integration | depends on API/auth |
+| MCP plugin | exposes tools to Agent | Agent can call it | needs schema and safety design |
+| Resource pack | ships tools/roles/skills/agents | simple and versionable | less interactive |
+
+Do not start with MCP unless the Agent must actively call your capability.
+
+## API Plugin Payload
+
+Include:
+
+- source tool and context;
+- target URL, method, key headers;
+- truncation policy for request/response bodies;
+- user intent;
+- authorization boundary.
+
+Large responses should be uploaded or summarized, not pasted whole into the prompt.
+
+## MCP Schema Design
+
+Bad:
+
+```json
+{"cmd":{"type":"string"}}
+```
+
+Better:
+
+```json
+{
+  "target_url": {"type":"string","description":"authorized target URL"},
+  "scan_profile": {"type":"string","enum":["passive","active-safe"]},
+  "max_requests": {"type":"integer","description":"request limit"}
+}
+```
+
+Specific schemas make HITL and Agent behavior safer.
+
+## Security Boundaries
+
+Plugins should not bypass platform controls:
+
+- no hidden destructive local commands;
+- no plaintext long-lived credentials;
+- no default third-party data exfiltration;
+- no dependency on browser state to bypass login.
+
+## Source Anchors
+
+- Burp plugin: `plugins/burp-suite/cyberstrikeai-burp-extension/src/main/java/burp/`
+- OpenAPI: `internal/handler/openapi.go`
+- External MCP: `internal/handler/external_mcp.go`