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LangGraph agent loop

contextweaver running inside a LangGraph agent loop, not as a replacement for one. LangGraph owns control flow; contextweaver owns phase-aware context compilation (route → firewall → answer); tool execution stays outside contextweaver.

TL;DR

What Where
The script examples/architectures/langgraph_agent_loop/main.py
Captured output examples/architectures/langgraph_agent_loop/OUTPUT.md
Local README examples/architectures/langgraph_agent_loop/README.md

Run it:

python examples/architectures/langgraph_agent_loop/main.py

(Or make architectures / make example. Install the framework path with pip install 'contextweaver[langgraph]'.)

The boundary

Concern Owner
Control flow (route -> execute -> answer, the per-turn loop) LangGraph StateGraph
Tool selection bounding (catalog → ChoiceCard shortlist) contextweaver route phase
Large tool-result firewalling contextweaver interpret phase
Budget-aware prompt + dependency-chain preservation contextweaver answer phase
Executing a tool The app / a tool runtime (here: mocked)

LangGraph is optional

The import is guarded. With LangGraph installed the real StateGraph drives the loop; otherwise an equivalent hand-rolled loop calls the same node functions in the same order. The output is identical apart from one agent loop engine: banner line, so the example runs under a bare pip install contextweaver. See the LangChain + LangGraph guide for the broader integration story.

The scenario

A two-turn ops session; the "model" decision at each node is a deterministic intent map standing in for an LLM holding the rendered ChoiceCards (no API key, no network):

  1. "pull the recent error logs for the payments service" → infra.logs_search returns a ~21 KB dump that the firewall compacts to a short summary.
  2. "summarize the root cause and draft an incident note" → incident.draft_note; the answer build carries turn 1's firewalled result forward.
  • The comparison page explains why contextweaver complements rather than replaces agent frameworks.
  • The catalog showcase is the framework-free version of the same route → firewall → answer flow.