When agents call agents, who's actually responsible?
In simple setups, a single agent talks directly to your APIs and LetsPing's behavioral firewall + HITL console is enough. In more complex environments, you have multiple agents, vendors, and tools calling each other. Without a standard, it becomes impossible to prove which agent triggered which action.
Agent-to-agent escrow gives every call a cryptographic identity and every handoff a signed envelope, so you can reconstruct the chain-of-custody for any request across internal teams and external providers.
Agent identities, not just API keys
Each agent gets a stable agent_id and secret. When it calls LetsPing, the SDK signs the canonical payload with HMAC-SHA256. The ingest pipeline verifies the signature against stored secrets and marks agent_signature_valid.
That identity flows into risk scoring, audit logs, and webhooks, so you can say “this exact agent, running this version, requested this action.”
Escrow envelopes for handoffs
When one agent hands off to another, LetsPing can attach an escrow envelope: a small structure containing the original request id, upstream and downstream agent ids, and a handoff_signature HMAC. Downstream agents use the SDK to verify this envelope before trusting the handoff.
The result is a verifiable chain of signed hops over a single LetsPing request id, even when different teams or vendors own the intermediate agents.
Same firewall and HITL console, extra guarantees
Escrow doesn't replace the behavioral firewall or human-in-the-loop console—it layers on top. The same guardrails and approval flows still decide whether a step should run. Escrow simply gives you strong attribution and handoff semantics when your architecture grows beyond a single agent.
You can adopt it incrementally: start by signing calls from a single critical agent, then extend to cross-team and cross-vendor hops as you standardize.
Next steps
• Read the Agent-to-Agent Escrow Spec for the exact wire format and verification rules.
• Use the helpers in the SDK: signAgentCall, verifyEscrow, and chainHandoff.
• Combine escrow with the behavioral firewall and HITL console to get end-to-end control over autonomous, multi-agent systems.