# Sentry has removed its legacy Alerts APIs — integrations now need Monitors and new Alerts Sentry’s August 17 cutoff is now effective: deprecated alert endpoints return `410 Gone`, with no backward-compatible endpoint or temporary exemption. API and Terraform users need to move alert creation and routing onto Sentry’s newer Monitor/Alert model. Sentry has completed a breaking alerting migration. Legacy alert APIs are gone; metric detection now lives in Monitors while notification routing lives in Alerts, and old direct integrations must use the replacement endpoints. - Status: Active - Published: 2026-08-22T15:25:09+12:00 - Updated: 2026-08-22T15:25:09+12:00 - Categories: Web Development, Cloud & Infrastructure, Developer Tools, Observability - Tags: API deprecation, API migration, Observability, Sentry, Terraform - Canonical HTML: https://beyondthe.news/dossiers/sentry-legacy-alerts-api-removed-monitors-alerts-migration ## What changed Sentry’s deadline for legacy Alerts API migration passed on August 17, 2026. Deprecated endpoints now return HTTP 410 and Sentry says there are no backwards-compatible endpoints or temporary exemptions. The replacement architecture splits detection from routing: Monitors define what to watch and create issues when conditions are met; Alerts define who gets notified and can be connected to multiple monitors. Sentry’s migration guide also points Terraform users to the newer resources introduced in provider version 0.15.4. ## Why it matters This is not a cosmetic API rename. Integrations that create or manage issue and metric alerts programmatically can now fail outright, and the replacement model changes how builders should represent alerting configuration. Detection conditions, issue creation and notification routing are separate resources, which can reduce duplication but requires migration work in internal tooling, Terraform modules and scripts. Teams that relied on old endpoints need to treat 410 responses as a broken production control path, not a transient outage. ## The old endpoints are gone, not merely deprecated Sentry’s migration guide says users had until August 17 to move, after which the legacy endpoints become unavailable. Deprecated calls return 410 Gone. Sentry explicitly says there is no compatibility endpoint or temporary exemption, so retrying or waiting will not restore an integration. ## Monitors detect; Alerts route The new architecture separates the condition that creates an issue from the action that notifies people. Metric, Cron, Uptime and other monitor types live under Monitors, while Alerts attach notification logic to issues and can connect one routing rule to multiple monitors. This is more composable than the old one-rule-per-alert shape but changes object models and IDs for API clients. ## Existing UI rules were migrated, custom automation was not Sentry says existing metric alert rules were migrated automatically in the product UI, with thresholds becoming Metric Monitors and notification actions becoming connected Alerts. That does not remove the need to update external code that still calls legacy endpoints. Internal provisioning systems, scripts and Terraform modules need to use the replacement APIs and resource types. ## Terraform has a defined replacement path Sentry points Terraform users to new provider resources, including `sentry_alert` and `sentry_metric_monitor`, added in version 0.15.4. Older `sentry_issue_alert` and `sentry_metric_alert` resources are also slated for deprecation in a future major provider version, so infrastructure-as-code users should migrate before a provider upgrade forces a second break. ## Key details - Legacy Sentry Alerts APIs became unavailable after August 17, 2026. - Deprecated endpoints return HTTP 410 Gone. - Sentry says there are no backwards-compatible endpoints or temporary exemptions. - The replacement model separates Monitors for detection from Alerts for notification routing. - One Alert can connect to multiple Monitors. - Sentry’s Terraform provider added new Alert and Monitor resources in version 0.15.4. ## Builder takeaways - Search code, Terraform and internal tooling for legacy Sentry alert endpoints now; treat 410 responses as a required migration, not a transient API failure. - Model detection and notification routing as separate resources so one routing policy can be reused across multiple monitors where appropriate. - After migrating, test end-to-end notification behavior rather than only successful API creation—the new object split can preserve resources while changing routing relationships. - If you use Terraform, move to the newer monitor/alert resources before upgrading into a provider version that removes the legacy resources. - Record replacement resource IDs and ownership during migration so operational teams can map old alert rules to new monitors and connected alerts. ## What to watch - The provider major release that fully removes deprecated Terraform alert resources. - Whether Sentry publishes additional migration tooling for large organizations with many programmatically managed rules. - Any follow-on API changes as the Monitor/Alert model stabilizes and legacy UI/backend code is removed. ## Uncertainties - Sentry’s help center is the clearest current source for the cutoff and replacement architecture; public independent reporting on the migration is limited. - Existing UI-created rules were migrated automatically, so the impact is concentrated on API, Terraform and custom-provisioning users rather than every Sentry customer. ## Sources - [Migrating to new detectors and alerts APIs](https://www.sentry.help/en/articles/15015315-migrating-to-new-detectors-and-alerts-apis) — Sentry · official migration guide. Primary evidence for the August 17 cutoff, 410 responses, no exemption, replacement API shape and Terraform path. - [Monitors & Alerts: Guide and FAQ](https://www.sentry.help/en/articles/15007504-monitors-alerts-guide-and-faq) — Sentry · official documentation. Explains the split between Monitors and Alerts, automatic UI migration and Terraform resource direction. - [Sentry 26.8.0 release notes](https://newreleases.io/project/github/getsentry/sentry/release/26.8.0) — Sentry / GitHub release mirror · repository release summary. Corroborates active removal of legacy alert pages and backend paths around the cutoff.