Agent( )
Pattern
INT·Jun 26

PrepareStep: Trim Message History

Demonstrate ToolLoopAgent prepareStep for trimming long message history. Pre-seeded 24-message conversation shows context compression on the first run with per-step trim telemetry.

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PrepareStep: Trim Message History preview

Problems Solved

  • Prevent unbounded message history growth in agent loops
  • Trim conversation context before each agent step
  • Keep recent tool results while dropping stale turns
  • Observe prepareStep compression with per-step telemetry

Use Cases

  • Long-running agent loops with many tool calls
  • Context window budget management
  • Production agents that must cap history size
  • Debugging what the model sees each step

AI SDK APIs

ToolLoopAgentprepareStepstepCountIstoolgateway

Tags

aiagentsprepare-stepcontext-windowmessage-trimmingtool-loop-agentai-sdkagent-api

Requirements

Node.js
24+
Memory
512MB
Other
  • OpenAI API key

Environment Variables

External Services

openai

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End of Pattern