System Prompt

agentOS automatically injects a system prompt into every agent session that describes the VM environment and available tools. The prompt is additive and never replaces the agent’s own instructions (CLAUDE.md, AGENTS.md, etc.).

The base prompt is embedded in the sidecar (not written to a file inside the VM). At session start the sidecar assembles the base prompt with your additional instructions and generated tool docs, then injects the result into the agent adapter’s launch arguments (for example, --append-system-prompt for Pi).

Customization

const session = await vm.createSession("pi", {
  env: { ANTHROPIC_API_KEY: process.env.ANTHROPIC_API_KEY! },
  // Append custom instructions
  additionalInstructions: "Always write tests before implementation.",
  // Suppress the base OS prompt (tool docs are still injected)
  skipOsInstructions: true,
});