After a Cursor agent deleted production in 9 seconds: building an agent permission gateway

Cold-Conclusion-6511 · reddit · 2026-10-25

Prompted by the April incident where a Cursor agent found a root token on disk and deleted a production database volume and backups in 9 seconds, the author designs a gateway between agents and their tools (MCP servers, APIs, other agents) that scopes what agents may call, issues short-lived narrow credentials, asks humans before irreversible actions, and keeps tamper-proof audit logs. Key design tensions discussed:

Approval prompts barely work: Claude Code users approve 97% of prompts; injected dangerous commands are caught only 13.6% of the time (5% after 50+ prompts), while 39% of whole plans get rejected vs 3% of individual commands — so ask rarely, on irreversible actions, and about plans.
Fuzzy detection alerts; hard limits (no delete calls, $20 budget) block — overly strict tools get ripped out.
Credentials cause 1/3 of 16 sampled incidents but include the most damaging cases.
Half of attacks run code directly on the machine, invisible to any proxy; sandboxing and network lockdown remain necessary.
Spend is uncovered: no gateway sums LLM + paid tool calls across an agent chain (A→B→C).
Agent-to-agent limiting standards exist, but real production adoption is unclear.

The author admits the proxy wouldn't have stopped that deletion and positions it as damage limitation, not a full fix.

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After a Cursor agent deleted production in 9 seconds: building an agent permission gateway

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