# Parabola vs. Relay.app

> Parabola vs. Relay.app: Relay.app pairs AI steps with human-in-the-loop approvals. Parabola runs fixed, inspectable logic over operational data at volume.

Source: https://parabola.io/parabola-vs/relay-app

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## TL;DR

Relay.app puts a person in the middle of the workflow. Parabola puts them at the end, on the exceptions.

- **Where humans fit:** Relay.app is built around approval steps inside a run. Parabola decides everything it can and routes the rest to a queue.
- **Scale:** Parabola is built for operational data volume rather than task-shaped workflows.
- **What runs each time:** Logic fixed at build time, identical on every run, with each step inspectable.
- **Where Relay.app genuinely wins:** Lightweight workflows that genuinely need a human approval in the middle.
- **Bottom line:** Pick Relay.app when approval is part of the flow. Pick [Parabola](/) when volume means attention has to be spent only on what did not match.

## Attention is the scarce resource

If a process runs a few times a day, pausing for a human to approve each one is reasonable. If it runs across 40,000 rows every morning, it is not — nobody approves 40,000 things.

Parabola is built on that assumption. The Flow applies the rules to everything, decides what it can decide, and produces an exception queue: the rows that did not reconcile, why each one is flagged, and what the recommended action is. Human attention goes to the small number of things that actually need it.

## Parabola vs. Relay.app at a glance

| Dimension | Parabola | Relay.app |
| --- | --- | --- |
| Human involvement | An exception queue at the end, for rows that need judgement | Approval steps inside the workflow |
| Scale | Batch operations over large operational datasets | Task and workflow-shaped work |
| Consistency | Fixed logic; the same input produces the same result | AI steps re-reason per run |
| Visibility | Step-level input, logic, and output, plus row-level tracing | Output and run-level |
| Output | An Artifact — an interactive, shareable app built from the Flow's data | Actions across connected tools |

## Which one is right for your team

Choose Relay.app when a person genuinely belongs in the middle of each run.

Choose [Parabola](/) when the volume is operational, the logic should be identical every time, and human judgement should be reserved for the exceptions.