𝗧𝗵𝗲 𝗔𝗴𝗲𝗻𝘁 𝗥𝘂𝗻𝘁𝗶𝗺𝗲 𝗘𝘃𝗲𝗻𝘁 𝗠𝗼𝗱𝗲𝗹
Stop arguing about agent frameworks.
Engineers often ask if they should use LangChain, CrewAI, or build their own. This is the wrong question. The real decision is where you attach policy inside your agent runtime.
Frameworks change. The architectural need for policy stays the same.
Every production agent stack needs four specific runtime events to prevent bugs and security leaks:
• UserPromptSubmit: Before the prompt reaches the model. Use this to block secrets and PII. • PreToolUse: Before a tool fires. Use this to enforce cost budgets and tool whitelists. • PostToolUse: After a tool returns. Use this to scan for PII or injection attacks. • Stop: After the agent finishes. Use this to verify the agent actually completed the task.
Each event has a different job.
Prompt submission must be fast. It needs to run in milliseconds so the user does not wait. The Stop event can take longer. You can afford a full second to verify if the agent actually did its job before the user sees the result.
You must also decide how your hooks fail.
If a security hook crashes, you should fail closed. It is better to deny a request than to leak a secret. If a quality check crashes, you might fail open so the user still gets a response.
Frameworks are a commodity. Your policy coverage is your moat.
Ask yourself these three questions about your current stack:
- Which event stops secret leaks in prompts?
- Which event catches an agent lying about finishing a task?
- Which event audits tool outputs for PII before the model reads them?
If you cannot answer these, your agent is not ready for production.
Source: https://dev.to/willianpinho/the-agent-runtime-event-model-55l9
Optional learning community: https://t.me/GyaanSetuAi