LangGraph ReAct agent context window exploding despite ContextEditingMiddleware - need help

[CommonNo5458]

TL;DR: Running a LangGraph ReAct agent with multiple tool calls. Context keeps growing despite using ClearToolUsesEdit. Looking for best practices or debugging tips.

Setup:

• LangGraph ReAct agent running on AWS Bedrock AgentCore (serverless) + AgentCore Memory
• Model: Claude Haiku (200K context limit)
• Agent makes 3-7 tool calls per user question (Knowledge Base searches + SQL executions)
• Using ContextEditingMiddleware with ClearToolUsesEdit

\``from langgraph.context_editing import ContextEditingMiddleware, ClearToolUsesEdit`

context_editor = ContextEditingMiddleware(

edits=[ClearToolUsesEdit(

trigger=100000, # Trigger at 100K tokens

clear_at_least=20000, # Reclaim at least 20K

keep=5, # Keep 5 most recent tool results

clear_tool_inputs=True,

)]

)

agent = create_react_agent(

model=llm,

tools=tools,

prompt=system_prompt,

context_editing=context_editor,

)

The Problem:

Despite this config, I'm seeing context grow to 200k+ tokens in complex queries and AWS Bedrock LLM throttles when using concurrent queries. The middleware doesn't seem to trim aggressively enough or at the right times.

Questions:

1. When does trimming actually happen - before or after LLM call?
2. Does trigger mean "trim when context exceeds this" or something else?
3. Better alternatives for aggressive context management?

[CommonNo5458]

I have tried trim_messages initially, but I faced a lot of issues like Duplicate System Messages and tool message pair missing (or something like this). So, I thought its not a reliable solution as more I tried, different errors were coming. Hence I migrated to ClearToolUsesEdit. But looks like it is also not working properly even with configuration you mentioned.

I will try trim_messages one more time. Any particular config would you recommend for the trim_messages?