Signal vs Coval

How Coval works

This page covers what Coval’s public pricing shows, read on 2 October 2026. It does not describe how their simulation or monitoring works, how they connect to Retell, or how they report a problem. For that, see their site.

Their plans bill for monitored calls and simulation minutes, so Coval sells simulated testing and production monitoring together, and each self-serve plan includes an allowance of both. Plans also set how many metrics a call can have: 10 on Starter, no limit on Growth.

Plans differ in history and projects too. Starter keeps traces for 30 days and has one project; Growth keeps them for 90 days and has five. Every plan has unlimited seats, and Enterprise adds unlimited projects.

Where Signal differs

This page covers only Coval’s pricing, so this section says what Signal does and leaves the feature comparison to their site.

Where the problem is. Signal reads your flow, including every step and transition, and places each issue on the step, tool or transition where it happens. Calls are grouped by the one change that would fix them.

How sure it is. Every cause says how it is known: measured by the platform, visible in the trace, inferred by a model, or not established. When nothing in the calls confirms a cause, it says so.

Proof on production. When a new version ships, Signal compares before and after once it has taken calls for a grace period, and says whether the difference is real or that there are not enough calls yet.

Nothing to choose first. Coval’s plans are sized partly by metrics per call. Signal has no metrics to pick: you approve a one-page brief drafted from your configuration, and it reads Retell over the API with no webhook.

Where Coval is stronger. Simulation on every plan, and unlimited seats from the smallest plan up. Signal‘s simulated tests replay stored production calls against a draft, within a monthly credit balance, and it has no synthetic callers. Its seats are set per plan below Enterprise.

What it costs

Coval has three plans. Starter and Growth are monthly plans, each with an allowance of monitored calls and simulation minutes: Starter includes 1,000 monitored calls and 100 simulation minutes, Growth 10,000 calls and 1,000 minutes. Both come with a seven-day trial that needs a card, and annual billing is 20% off. Enterprise is quoted, from a starting price their page prints.

Past the allowance, both plans charge overage, at a lower rate on Growth than on Starter. The page prints monitoring overage per minute even though the allowance counts calls, so ask Coval which unit applies before you estimate a busy month.

The price table on this page compares monitoring only. Coval’s plans also include simulation minutes, which the table does not count, and above Growth’s allowance its figure depends on which overage unit applies.

Signal charges a flat monthly plan with one balance of credits: each minute of a call costs a credit once it has started, and tests and the copilot draw on the same balance. Adding a check does not change the bill, and there is no charge per metric. There are no overage charges either: calls past the balance are stored, and analysed when the month resets or after an upgrade.

Using both

Signal reads Retell over the API and registers no webhook, so it leaves your agent’s settings as they are, whatever Coval’s integration needs.

1. Signal reads production and names the issue: the step, the cause, the calls behind it.
2. You test the change with Coval’s simulation before it ships.
3. After release, Signal checks production: did the issue shrink, and did anything else get worse.