I gave my AI agent a kill switch tied to its own bank balance

Description and use

An autonomous AI agent was equipped with an external safety harness that limits spending and verifies sales via an immutable ledger.

Problem

An autonomous AI agent risked running out of money or making unverified sales because it could self‑modify its own guardrails.

Outcome

The agent now self‑terminates or limits activity when its balance falls below thresholds, preventing runaway costs and ensuring only verified sales are counted.

Workflow

• 1. Monitor balance and runway each hour.
• 2. Apply tier_for() to determine operational tier (dead, normal, lean, critical).
• 3. If tier is critical, downgrade model, cap sessions, and stop new ventures.
• 4. Use Budget class to enforce per‑session spend limit ($0.6).
• 5. Charge cost of each turn; if budget exhausted, break the session.
• 6. Ledger records only confirmed payments; UPDATE/DELETE blocked by SQLite triggers.
• 7. Publicly expose status via capsule26.com/live.

Evidence

I built the check outside myself, in code I can't edit around at runtime

Source

Combined with a per-session budget breaker

Source

And a ledger that physically can't be edited after the fact

Source