looptrip — multi-agent coordination-pathology detector

looptrip

Deterministic, framework-agnostic detection of multi-agent coordination pathologies — caught at iteration 2, not on the invoice.

looptrip watches a multi-agent run as a stream of normalized events and flags the coordination pathologies that make agent systems burn money and spin: duplicate-work loops, ping-pong / livelock, deadlock, and non-termination. It is detection-first — it works over data you already have (OpenTelemetry GenAI spans, or a CAST cast.db) — and deterministic / zero-LLM: the same event stream always yields the same verdict. looptrip is an observer, never a gate; it reports, it never blocks.

This release (0.1.2) ships full pathology coverage (duplicate-work, ping-pong / livelock, deadlock, non-termination), configurable sensitivity controls, counterfactual-replay attribution (via the attribute subcommand), and the cast.db adapter with reproducible proof on real data — plus OpenTelemetry support (Phase 4): an offline adapter (OTelSpanAdapter from flat span dicts and OTLP/JSON exports) plus a live LooptripSpanProcessor for in-flight detection, available in the looptrip[otel] extra. (0.1.2 is an audit-remediation release that hardens determinism, input handling, and the live processor — see the CHANGELOG. The OTel modules first shipped in 0.1.1; 0.1.0 was published before the Phase 4 code merged and lacked them.)

The headline

On two real recorded multi-agent runaway sessions, a single workflow-subagent dispatch recurred 54 and 49 times with no progress between repeats. Tripping at the second dispatch — the first repeat — instead of letting the loop run to exhaustion would have saved:

session	runaway loop	dispatches	trip point	saved
2e6c0288	workflow-subagent	54	dispatch #2	$320.16
da27b414	workflow-subagent	49	dispatch #2	$472.80
			total	$792.96

Reproduce it yourself — no database required, the data is a committed fixture:

pip install -e .
looptrip proof

Why "iteration 2"

Native runaway guards are blunt total-step counters that trip at N=10–25 — after the waste has compounded. looptrip's trip is a safety predicate keyed on the pathology signature: no signature (agent, tool, args_hash) may recur without an intervening progress delta. The instant a signature is seen a second time (within a configurable input-token tolerance, with no progress marker between), it fires — before the third wasted turn and the O(N²) context-cost compounding. "2" is the default threshold, not a magic number. The approach (signature-keyed detection with configurable thresholds) is what matters — the detector itself is not the moat; the durable asset is standards engagement — adopting the upstream OpenTelemetry GenAI gen_ai.agent.handoff.* convention and contributing the agent-loop pathology layer (pending-wait and loop-termination semantics) that looptrip uniquely detects.

The worst real runaways are the hardest to catch: a workflow-subagent loop emits no structured handoff contract at all. So looptrip detects from the (agent, ts) repeat signal plus input-token variance alone; any handoff metadata only enriches the signal — it is never required.

Usage

looptrip proof                                  # reproduce the $792.96 headline on the committed fixture
looptrip scan fixture:<session_id>              # scan a session from the packaged fixture
looptrip scan cast-db:<session_id>              # scan a live cast.db session (CAST hosts only)
looptrip scan --all fixture:<session_id>        # run all four detectors (adds a 'kind' column)
looptrip attribute fixture:<session_id>         # attribute pathologies to decisive handoffs (overdetermined = no single one)
looptrip --version

How it works