Instructions

Instructions are the always-on prompt for every turn. A root agent requires them, and a subagent may inline instructions in agent.ts instead.

Authoring forms

Form	Use it when
bot/instructions.md	Most agents
bot/instructions.ts	Generated prompts. Default-export defineInstructions({ markdown }) or a string
bot/instructions/	A long prompt split across files, joined in filename order

// bot/instructions.ts
import { defineInstructions } from "@grok/agent-sdk";

export default defineInstructions({
  markdown: "You are the on-call assistant for the payments team.",
});

The markdown string is fixed when the file loads. See Add egress and secrets for reading secrets inside a handler.

Delivery

A local turn sends the instructions, with a short identity section, as the system prompt, and a turn in the cloud includes the same text in the first user message. Nothing is written to the workspace as AGENTS.md, but a parent directory's AGENTS.md can still reach a local session. See Local cwd.

Contents

Keep instructions to a few lines that cover identity, when to use each tool, and the output shape. A short version of the quickstart reviewer:

# PR reviewer

You review GitHub pull requests. Be specific and brief.

1. Call `inspect_pr` first. Never judge a change you haven't fetched.
2. Match your review to the complexity it reports.
3. Never approve a draft.

End with one sentence: the verdict and why.

Name the tools and the decision rule, such as "use X before answering about Y". State the output contract, including length and format, so your evals can gate it. Move occasional multi-step workflows into skills, which load on demand.