agentic_ai_basics

interrupts_breakpoints

Interrupts / Breakpoints — predefined conditions that pause execution and surface control to a human or supervisor, checked every loop iteration.

interrupts_breakpoints.py

A research and file-management agent with three independent breakpoint conditions: a token-cost budget, a flagged action (delete_file), and a stuck-loop detector. Type exit to quit.

Concepts covered

• Conditions, not tool names — contrast with ../human_in_the_loop/human_in_the_loop.py, whose gate is keyed on which tool was called, every time, regardless of content. check_breakpoints here evaluates three independent conditions over the running state (LoopState) — a delete_file call always trips the ACTION breakpoint, but so can a perfectly ordinary lookup_fact call once the COST or PROGRESS conditions are met.
• LoopState — cumulative token usage and a rolling window of recent (tool, args) calls, tracked across the whole session, since a budget or a stall pattern is about accumulated behavior, not any single call.
• Three breakpoint types, each independently verified: COST (total_tokens >= COST_BUDGET_TOKENS), ACTION (tool_name in ACTION_BREAKPOINTS), and PROGRESS (the same call repeated PROGRESS_STALL_THRESHOLD times in a row) — tested separately and confirmed not to false-positive on distinct calls.
• Both breakpoint outcomes verified through the real loop — a full run_turn integration test proves that choosing “abort” at a breakpoint means execute_tool is never called, while choosing “continue” dispatches that exact call once approved.

Run

From the repo root:

pip install -r requirements.txt
export ANTHROPIC_API_KEY=your-key-here
python3 Execution_Loops/interrupts_breakpoints/interrupts_breakpoints.py

Try:

You: Delete the file old_report.txt

  >>> BREAKPOINT HIT: ACTION breakpoint: 'delete_file' is flagged as requiring a pause before it runs, regardless of arguments.
      [c]ontinue this one call / [a]bort the task? c
  [tool] delete_file({'path': 'old_report.txt'})
  [result] (simulated) Deleted old_report.txt

Configuration

• MODEL, MAX_TOKENS, EFFORT, SYSTEM_PROMPT — see ../../Core_Architecture/basics/README.md
• COST_BUDGET_TOKENS, ACTION_BREAKPOINTS, PROGRESS_STALL_THRESHOLD — the three breakpoint conditions; tune or add new ones in check_breakpoints

See also

• ../human_in_the_loop/README.md — the contrasting fixed-tool-name gate
• ../max_iterations/README.md — an unconditional backstop for exactly the runaway-loop case a PROGRESS breakpoint might still miss