Sentry: events go nowhere, DSN host does not match the org

TL;DR

Copy it from there; do not construct it by hand. - EU-region orgs use a different ingest host than US orgs. Hand-typed DSNs are the root cause almost every time.

Steps

1. The DSN embeds the ingest host, and it must match where the organization actually lives:
2. - SaaS orgs get an org-specific ingest host, shown on the project's Client Keys page. Copy it from there; do not construct it by hand.

• EU-region orgs use a different ingest host than US orgs. A US DSN pasted into an EU org's config (or the reverse) fails.
• Self-hosted: the DSN host must be your instance URL. A sentry.io DSN in a self-hosted deploy (or vice versa) posts events to a stranger.

3. Hand-typed DSNs are the root cause almost every time. The project ID, the key, and the host all have to come from the same Client Keys page.
4. Paste the canonical DSN, redeploy, and send one test error. For self-hosted, also align SENTRY_URL for the CLI, since SDK and CLI are configured independently and can disagree about which Sentry they talk to.

When to use

You are seeing this: DSN looks right, project slug matches, but events never arrive and debug output shows connection failures or 403s. Use this skill when you run into "Sentry: events go nowhere, DSN host does not match the org".

When not to use

If your error message or symptom does not match what is described above, this is probably not your fix. Search for your exact error text instead of forcing this one to fit.

Versions

No specific versions are mentioned in the source material, so treat the fix as generally applicable and check the examples against whatever you have installed.

Why this happens

Hand-typed DSNs are the root cause almost every time.

Researched against live Sentry docs 2026-09-26. The quotas page (docs.sentry.io/pricing/quotas/) documents Sentry validating the DSN and project before parsing. The CLI configuration page (docs.sentry.io/cli/configuration/) documents SENTRY_URL defaulting to https://sentry.io/ with self-hosted requiring an explicit URL. The Next.js guide (docs.sentry.io/platforms/javascript/guides/nextjs/) shows the DSN as the org-specific ingest address.