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Agentic Loopiness

alex-krentsel's visual for how agent systems stack: nested matryoshka dolls where each outer shell is a new loop around the layer below. A compact way to explain why phase-3 agents aren't qualitatively different kinds of programs — they're just the next outer doll.

The nesting

From inside out:

  1. Transformer inference — one forward pass, one next token. (The 2017 paper.)
  2. LLM generation — transformer in a loop over tokens; produces a full response.
  3. Assistant — LLM in a loop over turns; multi-step conversation, internal reasoning passes.
  4. Scoped agent — assistant in a loop over tool calls; read/write files, run commands.
  5. Autonomous agent — scoped agent in a loop over tool discovery and self-modification; owns its environment, adds skills, edits config.

Each layer is "just" the previous one wrapped in a new while loop. The outer layer you accept determines what the system can be.

Why it's useful

  • Reifies the "harness" — a harness is whatever code runs the outermost loop. See harness-engineering.
  • Separates capability from authorship. Each loop shifts more control-flow authorship from the human to the model.
  • Predicts the next layer. Krentsel's open question: what's outside phase-3? He guesses malleable architecture — a loop where the architecture itself is edited by the agent, not just skills/config.

Strange-loops connection

Krentsel explicitly invokes Hofstadter's Gödel, Escher, Bach: at the autonomous-agent level, the loop wraps all the way around — the agent is now the interface by which the agent is reconfigured. The edges of "author" and "subject" blur. He reads this as a flywheel-takeoff signal.

Pairs with

Cross-references