Build
Tools & state
Execute actions where authorization and state live
Router transports tool-call intent; Reef and the product validate and execute tools.
Define narrow tools
Use explicit JSON Schema, stable names and minimal outputs. Do not give the model raw credentials, broad database access or a generic shell.
Control side effects
Use idempotency keys and durable tool execution state. A network retry or model replay must not create duplicate payments, messages or record mutations.
Keep workflow state in Reef
Conversation state, checkpoints, tool results and recovery metadata remain in Reef or product-owned storage—not Router logs.