Give every agent an identity, a budget, and a leash.

Autonomous workloads need spend caps and tool-call review that a shared API key cannot express.

Each agent gets its own key, budget and kill switch, separate from the humans who deployed it.
Every tool and MCP call is graded before it runs, with the risky ones held for human approval.
Automatic failover keeps long agent loops alive when a single provider starts rate-limiting.

A shared API key cannot express this.

Autonomous workloads need a budget of their own, a tool policy of their own, and an off switch that does not take the rest of production with it. That is three things a single key in an environment variable will never give you.

Long loops, live providers.

Agents run long enough to meet a rate limit. Automatic failover keeps the loop alive across 200+ models, and every tool call it makes on the way is graded before it runs.