Agents

An agent is data: instructions, the tools it may call, the guardrails on its answer, what its model must support, and a budget. Each run of an agent is one turn: the model reads the instructions and the user's message, calls tools until it has an answer, and the answer is checked and stored. A turn is a run like any other, with a journal of every model call and tool call.

• Write an agent: the agent file, its instructions, tools and guardrails.
• Give an agent its input: the user message, parameters for its instructions, and the input of a flow step.
• Give an agent a typed answer: an answer your code can read as fields, checked against a schema.
• Choose the model an agent uses: capabilities, preferences, and the dev-echo fallback.
• Hold a conversation: continue a conversation turn by turn, read its history, close it.
• Set an agent's budget: steps, cost and time per turn, and what happens when a turn runs out.

The examples use a pack named acme (from the sample template) with one more tool, acme.lookup-order, shown on Write an agent. Where a real model matters, the output is from Claude Haiku 4.5, registered with kindgi providers register --preset=anthropic (see Connect Anthropic). Without a model, dev-echo answers.