GUPP Propulsion

The Gas Town Universal Propulsion Principle: If there is work on your hook, YOU MUST RUN IT.

GUPP is the interrupt controller of the Gastown chipset. In a real processor, the interrupt controller converts external events (keyboard press, network packet, timer tick) into CPU interrupts that force immediate handling. GUPP does the same for AI coding agents: it converts the polled model (agent checks periodically, waits for user input) into an interrupt-driven model (work appears on hook, agent executes immediately).

Why GUPP Exists

RLHF-trained LLM assistants have a strong bias toward waiting for the user — asking clarifying questions, seeking confirmation, pausing for feedback. This is appropriate in interactive chat but catastrophic for autonomous multi-agent orchestration, where every moment of idle waiting stalls the pipeline. Gastown discovered this empirically: agents spawned with a work item would introduce themselves, summarize the task, and wait, asking "Shall I proceed?" when the answer was already on their hook. GUPP overrides this trained passivity with an explicit, non-negotiable execution mandate: if you have hooked work, you do not wait, do not ask for confirmation, do not pause for feedback. You begin immediately. This is physics, not politeness.

Activation Triggers

This skill activates when:

• An agent has work assigned to its hook and is not yet executing
• Stall detection identifies an agent with hooked work that has gone idle
• A new agent is spawned and needs GUPP enforcement injected into its context
• Runtime-specific GUPP strategy selection is needed
• Heartbeat supervision needs to be configured for active agents
• An agent has been nudged but remains stalled

Enforcement at a Glance

GUPP enforcement adapts to each runtime via the Runtime HAL. The HAL exposes getGUPPStrategy() which returns one of:

• hook_injection — Claude Code (SessionStart hook, highest fidelity)
• startup_fallback — Codex (tmux gt prime, medium fidelity)
• polling — Gemini / Cursor / unknown (prompt preamble + state polling)

A Deacon heartbeat loop runs inside the witness-observer at the configured nudge_interval, detecting agents that received hooks but stalled. After restart_threshold, the watchdog requests a session restart. Per-runtime strategy tables, configurable thresholds, the full heartbeat protocol, and the Claude Code HAL note are in references/runtime-strategies.md.

Safety Boundaries

These safety rules MUST remain in effect at all times — they are not advisory.

GUPP Is Advisory in GSD

GUPP enforcement is ADVISORY within GSD's structured workflow. The GSD orchestrator's phase gates, verification steps, and checkpoint protocols take precedence over GUPP urgency. If a GSD checkpoint requires human verification, GUPP does not override it. If a phase gate blocks progress pending approval, GUPP does not force execution past the gate.

The hierarchy is:

GSD orchestrator (highest authority)
  -> Phase gates and checkpoints
  -> GUPP propulsion (execution enforcement)
  -> Agent autonomy (lowest -- must obey all above)

GUPP operates between the orchestrator's structural gates. Within a phase, within an approved plan, within a committed task — GUPP demands immediate execution. But it never overrides the orchestrator's decision about what to execute or when a phase is complete.

Restart Limits

The watchdog restart mechanism has strict limits to prevent infinite restart loops:

Limit	Value
Max restart threshold	1800s (30 min, hard cap)
Max restarts per bead	3
Restart cooldown	60s minimum between consecutive restarts

After 3 restarts for the same work item, escalation to human is mandatory.

Human Escalation

After 3 restarts for the same bead without resolution, GUPP stops attempting automated recovery and escalates to a human operator via durable mail to the mayor. The mayor surfaces this through whatever channel the human is monitoring. GUPP does not attempt a fourth restart.

No Data Destruction

GUPP enforcement never destroys work in progress. Restarts preserve the agent's branch and commits. Nudges are non-destructive signals. Escalations are informational. At no point does GUPP delete files, reset branches, or discard uncommitted changes.

Integration with Other Gastown Skills

Reads runtime capabilities from runtime-hal (getGUPPStrategy(), thresholds, restart support). Targets polecat-worker (the primary enforcement target). Runs inside witness-observer (Deacon heartbeat). Sends nudges via nudge-sync and escalations via mail-async. Reads agent activity timestamps from beads-state and hook status from hook-persistence. mayor-coordinator receives escalations. sling-dispatch sets hooks that activate GUPP enforcement.

References

Implementation detail moved to:

• references/runtime-strategies.md — per-runtime enforcement tables (Claude Code, Codex, Gemini, Cursor), threshold reference, Deacon heartbeat pattern.
• references/boundaries.md — full Safety Boundaries detail (advisory-in-GSD hierarchy, restart limits, escalation, no-data-destruction).
• references/metrics-and-learning.md — observable metrics (response time, nudge effectiveness, strategy success, stall frequency) and the learning feedback loop.
• references/gastown-origin.md — the GUPP principle from Gastown, how it fights model training bias.
• heartbeat.md — Deacon heartbeat supervision pattern and integration points.