Stack traces

Error tracking enables you to view the stack trace and code context associated with an exception. This can help understand, identify and resolve the root cause of an issue.

For languages like Python, the stack trace and code context can be gathered by the PostHog client and requires no additional processing.

Symbol sets

Compiled or minified languages requires additional information to perform a process called symbolification to produce the same stack trace and code context output shown above. The additional information is known as a symbol set.

The source of a frame in the exception stack trace should point to the minified code of your application which should contain the sourceMappingUrl parameter denoting the location of the source map. These files must either be publicly accessible for PostHog to fetch or uploaded manually to symbolify the stack trace.

You can see the symbol sets fetched by PostHog and the associated frames within the error tracking settings. Any missing symbol sets will also be present along with the failure reason. From here, you can also manually upload missing symbol sets or replace existing ones.

Uploading source maps

If your source maps are not publicly hosted, you will need to upload them during your build process to see unminified code in your stack traces, you can either use the @posthog/nextjs-config package or the posthog-cli to handle this process.

npm install @posthog/nextjs-config

import { withPostHogConfig } from "@posthog/nextjs-config";

const nextConfig = {
  //...your nextjs config,
};

export default withPostHogConfig(nextConfig, {
  personalApiKey: process.env.POSTHOG_API_KEY, // Personal API Key
  envId: process.env.POSTHOG_ENV_ID, // Environment ID
  host: process.env.NEXT_PUBLIC_POSTHOG_HOST, // (optional), defaults to https://us.posthog.com
  sourcemaps: { // (optional)
      enabled: true, // (optional) Enable sourcemaps generation and upload, default to true on production builds
      project: "my-application", // (optional) Project name, defaults to repository name
      version: "1.0.0", // (optional) Release version, defaults to current git commit
      deleteAfterUpload: true, // (optional) Delete sourcemaps after upload, defaults to true
  },
});