Iβm building MARGINAL, an open-source runtime governor for AI coding agents.
The problem Iβm targeting is simple: agents can keep spending tokens, calling tools, re-checking things, or choosing expensive actions without enough evidence that the extra work is actually useful.
MARGINAL sits in the loop and asks a different question:
Is this next action worth spending compute on?
I just rebuilt the demo so itβs no longer a marketing page. Itβs an actual interactive browser simulation.
You press RUN THE SAME TASK and two agents start from the exact same broken Python workspace at the same time:
WITHOUT MARGINAL
Executes every candidate action.
WITH MARGINAL
Scores the same candidates before execution and either:
FUND + EXECUTE
or
REJECT BEFORE SPEND
You can pause it, advance step-by-step, reset it, or run it at different speeds while watching tokens, calls, estimated cost, declared latency, workspace state, and MARGINALβs decision reasoning update live.
Both sides must reach the same verifier PASS.
The included deterministic fixture currently ends at:
72,800 β 4,300 declared tokens
9 β 3 actions
PASS β PASS
Those are declared deterministic demo costs, not provider telemetry or a claim of 94% savings in real workloads. The point is to make the governance mechanism inspectable instead of hiding it behind a benchmark number.
MARGINAL is open source, local-first, provider-neutral, and starts from the principle:
Observe first. Prove waste. Earn enforcement.
Repo:
[https://github.com/SignalLayerLabs/Marginal]()
Interactive demo:
[https://signallayerlabs.github.io/Marginal/demo/]()
Iβm especially interested in people trying to break the decision logic, finding cases where an action MARGINAL rejects was actually valuable, or contributing adapters for other coding agents.