Releases

The release option tags every event and error with the version of your app that produced it. This lets you compare error rates between deploys, see which version introduced a bug, and track whether a fix actually resolved an issue.

Setting a release

Pass release to init(). Any string works — semver, git SHA, or a deploy ID:

import { init } from "@emit-vision/sdk-js";
 
init({
  apiKey: process.env.EMIT_VISION_API_KEY,
  release: process.env.APP_VERSION ?? "dev", // e.g. "2.4.1" or "abc1234"
  environment: "production",
});

Good sources for the release string:

What you see in the dashboard

The Releases tab shows:

• Each unique release value seen in the last 30 days
• New errors — errors first seen in that release
• Resolved errors — errors from a previous release not seen since
• Error rate — events-to-errors ratio for the release period
• Adoption — what fraction of sessions are on the new release

Release-aware error grouping

In the Errors tab, every error group shows:

• First seen in — the release where this error was first captured
• Last seen in — the most recent release where it appeared
• Affected releases — all releases where at least one occurrence was recorded

This lets you verify that a bug fix actually worked: if the error's "last seen in" matches the release before your fix, it's resolved.

What changed this release

Open a release from the Releases tab to see how it moved the numbers compared with the release before it. The same verdict appears on the compare page and in the weekly digest.

How the baseline is picked

The baseline is the previous release by first-seen time in the same environment. A release that has only run in staging is never compared with one from production. Use Compare against to pick a different baseline.

Aligned windows

Both releases are measured over the same length of time from the moment each one first appeared, so a release that has been live for a week is not compared with a few hours of the new one. The window is capped at 7 days. The page states the exact window it used, for example "Comparing the first 3d of each release."

When there is no number

• Too early to compare — the release has been live for less than 1 hour, so nothing is calculated.
• First release in this environment — there is no baseline. You still see health and error movement for the release, but no comparison.
• Not enough sessions yet — a rate needs at least 50 sessions in both windows. Below that the dashboard shows the session count instead of a percentage, because a rate from a handful of sessions is noise. A dash means the data is not available.

Error movement

Each error group is placed in one of four categories:

Each list shows up to 10 groups. Each row links to the error group, filtered to the release and environment.

Segments

Most affected segments (browser and country) show each segment's error-session rate before and after. Contribution is how much the segment's share of all error sessions moved between the baseline and this release, in percentage points. A large positive value means errors are concentrating in that segment. It is blank when there is no baseline. Segments with fewer than 50 sessions are left out.

In the weekly digest

The weekly digest lists up to three production releases first seen that week, each with its verdict, error-session and crash-free changes, the top new error, and a link to the full page. Releases that are too early show "Too early to compare".

Node.js

Set release in the Node SDK the same way, typically from an env var populated at deploy time:

import { init } from "@emit-vision/sdk-node";
 
init({
  apiKey: process.env.EMIT_VISION_API_KEY,
  release: process.env.APP_RELEASE ?? "local",
  environment: process.env.NODE_ENV ?? "development",
});

Per-event overrides

If you need to tag a specific event with a different release (e.g., a background job running an older version), pass it in options:

import { captureEvent } from "@emit-vision/sdk-js";
 
captureEvent(
  "migration_completed",
  { version: "v3" },
  {
    release: "[email protected]",
  },
);

This overrides the global release for that single event only.