Mental Model

Ed Donner

Five layers for LangGraph Sidekick — Intake through Return — plus which Anthropic workflows the Worker and Evaluator use.

LangGraph · Gradio · ChatOpenAI · ToolNode · MemorySaver

Overview

The co-worker loop is easiest to hold as five layers. AI sits in Work and Evaluate; Intake, Act, and Return are Gradio input, tools, and UI output. Anthropic names from Building effective agents (PDF).

Applied workflows

  • Evaluator-Optimizer. Worker produces a reply; Evaluator scores it against success criteria and either ends or loops the worker with feedback.
  • Not used here (yet). Routing, Parallelization, Prompt Chaining, Orchestrator-Worker — one worker / evaluator pair in a LangGraph, not a multi-worker fan-out.

Layers

  • 1 Intake. Gradio collects request + success criteria; run_superstep seeds graph state and a MemorySaver thread id.
  • 2 Work. Worker rewrites its system prompt from criteria (and prior feedback), invokes gpt-4o-mini with bound tools.
  • 3 Act. worker_router sends tool calls to ToolNode (Playwright, Serper, Wikipedia, REPL, sandbox files, Pushover), then back to Work.
  • 4 Evaluate. Evaluator returns structured EvaluatorOutput: feedback, success_criteria_met, user_input_needed.
  • 5 Return. On success or clarify need, graph ends; Gradio shows assistant reply plus evaluator feedback. Otherwise Evaluate routes back to Work.

Layer map

Layer stack for one Gradio Go. Diagram key: ✦ AI agent · second line = Anthropic workflow · purple = actor · white = service.

---
config:
  theme: default
  themeVariables:
    background: "#ffffff"
    fontSize: "14px"
---
flowchart TB
    person[Person]
    intake["1 Intake
request and criteria"] work["✦ 2 Work
Evaluator-Optimizer"] act["3 Act
ToolNode"] evaluate["✦ 4 Evaluate
Evaluator-Optimizer"] returnNode["5 Return
reply and feedback"] person -->|Go| intake --> work work -->|tool calls| act --> work work -->|text| evaluate evaluate -->|retry| work evaluate -->|done or clarify| returnNode --> person classDef agent fill:#e8f0ee,stroke:#0f3d36,stroke-width:2px,color:#0d0d0d classDef service fill:#fafaf8,stroke:#c8c8c2,stroke-width:1px,color:#0d0d0d classDef actor fill:#f3eef8,stroke:#6b4f9a,stroke-width:2px,color:#0d0d0d class work,evaluate agent class intake,act,returnNode service class person actor

Read layers top to bottom; drill into agent tabs for prompts and routing helpers.

Use this tab as the layer map and Anthropic workflow callout for Worker and Evaluator. Product overview stays on Project.