An agent in your chain is not installed

AGENT_UNAVAILABLE · exit 20 · needs a person

A connected agent's binary is missing or not on PATH, so nothing was run for its turn. Relay fails over to the next agent in the chain and says so; an empty chain becomes an escalation.

Clears when

The binary returns to PATH, or the chain is reconnected without it.

Commands

relayevals connect
relayevals doctor

Every state, with its exit code, is listed in the documentation. An agent that reaches an unfamiliar state should run relayevals next --format json and follow the single action it returns.