Sentry
Receive bounded error events, group them, link releases, and notify one team
The core loop is buildable, but a dependable replacement becomes a real weekend or multi-day project. For Sentry, receive bounded error events, group them, link releases, and notify one team. The hard boundary is sdk ecosystem, grouping models, tracing, replay, global ingestion, and enterprise operations, plus independent infrastructure and reliable alerting.
Build verification: not recorded. How we judge buildability
What you give up
- SDK ecosystem, grouping models, tracing, replay, global ingestion, and enterprise operations
- global probe network
- phone and SMS delivery
- massive retention
- advanced incident response and support
Why people still pay
People still pay for Sentry because monitoring must continue working during the exact outage it reports, which makes independent infrastructure and alert delivery the real product. The recurring cost buys probe geography, clocks, retries, deduplication, sampling, storage, paging, notification delivery, on-call rules, and its own uptime, not just the visible interface.
Your build guide
The stack, security requirements, and agent rules for a focused replacement.
Before you start
- Runtime and tools: TypeScript, Node, Express, better-sqlite3 and a durable ingestion/alert worker with an authenticated server-rendered issue dashboard.
- Before starting: An HTTPS intake URL, private administrator access, two disposable project tokens, explicit byte/event quotas and retention, a configured alert channel, and synthetic duplicate, malformed, secret-bearing and release-regression events.
Use these project rules and optional skill references alongside the prompt. Review each skill before adding it to your agent; the AGENTS.md export includes the same guidance.
Project rule — domain: Store Project, HashedProjectToken, SanitizedEvent, IngestReceipt, FingerprintVersion, IssueGroup, Release and AlertOutbox; deduplicate event IDs within the project, keep grouping stable across volatile request IDs, and reopen only an explicitly resolved group when a matching error recurs.
Project rule — scope and recovery: Use a documented small JSON intake protocol and sample sender, not an unsupported claim of Sentry SDK compatibility. Strip credentials and private request bodies before storage. Start without session replay or arbitrary source-map downloads; quotas, retention, release ordering and grouping heuristics remain explicit limitations.
Project rule — acceptance: Replay one event ID and send the same stack under a second ID; store two occurrences in one group. Resolve it, send the error in a new release and restart its worker; record one regression transition and one alert intent. Invalid tokens and oversized/malformed payloads are rejected, while a secret-bearing fixture is redacted before durable storage.
Project rule — delivery: document real setup commands and permissions; do not claim a build, accuracy level, performance result or security certification that has not been demonstrated.
Recommended skill: web-design-guidelines — review keyboard access, focus, validation, error recovery and the readable work/review interface or HTML report. Follow the maintainer's installation instructions and match its requirements to the chosen runtime.
Recommended skill: sharp-edges — review configuration and API defaults against the app-specific invariants and recovery boundaries above; this is not a security certification. Follow the maintainer's installation instructions and match its requirements to the chosen runtime.
Implementation plan
Phase 1
Pin the working slice and create its example input: Accept bounded application-error events, group similar failures, attach release IDs and alert on first-seen or regressed issue groups for one team. Confirm setup: An HTTPS intake URL, private administrator access, two disposable project tokens, explicit byte/event quotas and retention, a configured alert channel, and synthetic duplicate, malformed, secret-bearing and release-regression events.
Phase 2
Implement persistence and write-time invariants before decorating the UI: Store Project, HashedProjectToken, SanitizedEvent, IngestReceipt, FingerprintVersion, IssueGroup, Release and AlertOutbox; deduplicate event IDs within the project, keep grouping stable across volatile request IDs, and reopen only an explicitly resolved group when a matching error recurs.
Phase 3
Connect the working view to real saved state. Authenticate intake with hashed, rotatable project-scoped tokens and derive the project from the token. Cap payload bytes, stack frames, properties and per-project intake before accepting work. Allowlist and redact fields before queueing, storage or logging; reject malformed events without recording their contents. Deduplicate by project and event ID, retaining the original receipt on retry. Group sanitized events with a versioned fingerprint excluding volatile IDs. In one transaction, mark the queued event processed, update its issue/release state and enqueue one alert per first-seen or resolved-to-regressed transition. Lease pending jobs across worker restarts; retain uncertain notification delivery for review instead of blindly sending again. Intake tokens grant no dashboard access; authenticated administrators can resolve groups and review alert status.
Phase 4
Expose the app-specific limits and recovery path in context: Use a documented small JSON intake protocol and sample sender, not an unsupported claim of Sentry SDK compatibility. Strip credentials and private request bodies before storage. Start without session replay or arbitrary source-map downloads; quotas, retention, release ordering and grouping heuristics remain explicit limitations.
Phase 5
Walk through this concrete acceptance case and preserve its exported evidence: Replay one event ID and send the same stack under a second ID; store two occurrences in one group. Resolve it, send the error in a new release and restart its worker; record one regression transition and one alert intent. Invalid tokens and oversized/malformed payloads are rejected, while a secret-bearing fixture is redacted before durable storage. Finish the README and backup/restore instructions; report unfinished capabilities explicitly.
Build the following focused alternative to Sentry. This is a deliberately limited personal or small-team substitute, not parity with the paid service. WORKING SLICE Accept bounded application-error events, group similar failures, attach release IDs and alert on first-seen or regressed issue groups for one team. SETUP AND ARCHITECTURE Use TypeScript, Node, Express, better-sqlite3 and a durable ingestion/alert worker with an authenticated server-rendered issue dashboard. Prerequisites: An HTTPS intake URL, private administrator access, two disposable project tokens, explicit byte/event quotas and retention, a configured alert channel, and synthetic duplicate, malformed, secret-bearing and release-regression events. Before integrating anything, record actual versions and permissions, plus model files or provider limits only where used, in the README; make unavailable dependencies visible rather than simulating success. DOMAIN MODEL AND INVARIANTS Store Project, HashedProjectToken, SanitizedEvent, IngestReceipt, FingerprintVersion, IssueGroup, Release and AlertOutbox; deduplicate event IDs within the project, keep grouping stable across volatile request IDs, and reopen only an explicitly resolved group when a matching error recurs. IMPLEMENTATION CONTRACT Authenticate intake with hashed, rotatable project-scoped tokens and derive the project from the token. Cap payload bytes, stack frames, properties and per-project intake before accepting work. Allowlist and redact fields before queueing, storage or logging; reject malformed events without recording their contents. Deduplicate by project and event ID, retaining the original receipt on retry. Group sanitized events with a versioned fingerprint excluding volatile IDs. In one transaction, mark the queued event processed, update its issue/release state and enqueue one alert per first-seen or resolved-to-regressed transition. Lease pending jobs across worker restarts; retain uncertain notification delivery for review instead of blindly sending again. Intake tokens grant no dashboard access; authenticated administrators can resolve groups and review alert status. Provide an input/setup view, the main work view, and a review/export view appropriate to this workflow. Preserve the last saved state if a job or save fails. Include empty, loading, permission-denied, partial and retryable-error states. Log identifiers and error categories without secret values or unnecessary private content. APP-SPECIFIC BOUNDARY AND RECOVERY Use a documented small JSON intake protocol and sample sender, not an unsupported claim of Sentry SDK compatibility. Strip credentials and private request bodies before storage. Start without session replay or arbitrary source-map downloads; quotas, retention, release ordering and grouping heuristics remain explicit limitations. ACCEPTANCE SCENARIO Replay one event ID and send the same stack under a second ID; store two occurrences in one group. Resolve it, send the error in a new release and restart its worker; record one regression transition and one alert intent. Invalid tokens and oversized/malformed payloads are rejected, while a secret-bearing fixture is redacted before durable storage. Also reopen the app after an interrupted operation, confirm the saved record/export remains inspectable, and document the recovery action. These are implementation acceptance requirements, not a claim that this guide has been tested. DELIVERY Deliver a runnable repository with migrations or project-format versioning, a non-sensitive example, environment/permission setup, the exact manual acceptance steps, and a backup/export-and-restore walkthrough. Implement the working slice before optional integrations; list any deferred paid-product capabilities honestly. Do not add capabilities outside the working slice just to resemble the original product. PROJECT RULES FOR AGENTS.md Keep the domain invariants above executable at the write boundary. Propose scope changes before adding providers or permissions. Never fabricate source evidence, publish results, identity matches or successful delivery. Preserve user originals and require an explicit confirmation for destructive changes or external publication.
$ open in your agent (prompt prefilled, you press enter), copy the prompt or copy or download AGENTS.md · generated from this app's build plan
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Alternatives to building your own
all 3 free alternatives to Sentry →· no votes, no pay-to-list · just what's real
Sentry pricing
| plan | monthly | annual (per mo) | what you get |
|---|---|---|---|
| developer | $0/workspace | $0/workspace | 1 user; unlimited projects; 5,000 errors; 5 GB logs; 5 GB app metrics; 5 million spans; 50 replays; 30-day retentionPermanent free plan. |
| team | — | $26/workspace | Unlimited users/projects; 50,000 errors; 5 GB logs; 5 GB app metrics; 5 million spans; 50 replays; up to 90-day retention$26/month equivalent when billed annually; monthly-toggle amount was not exposed in the crawl. |
| business | — | $80/workspace | Unlimited users/projects; Team base event allowances; 1,000 metric monitors; unlimited dashboards; business controls$80/month equivalent when billed annually; monthly-toggle amount was not exposed in the crawl. |
| enterprise | — | — | Custom event volumes, support, retention, security and contract termsContact sales. |
free tier1 user; unlimited projects; 5,000 errors, 5 GB logs, 5 GB app metrics, 5 million spans and 50 replays/month; 1 uptime monitor, 1 cron monitor, 20 metric monitors, 1 GB attachments and 100 builds
billingmonthly + annual; published annual equivalents for Team and Business
hidden costsErrors, spans, replays and other event categories can overage separately; logs/app metrics are $0.50/GB, uptime alerts $1 each, cron monitors $0.78 each, profiling is metered, and Seer AI is a separate usage charge
pricing sources checked 2026-08-14 · pricing source ↗
Questions about Sentry
Can you build your own Sentry with AI?
Partly. The core loop is buildable, but a dependable replacement becomes a real weekend or multi-day project. For Sentry, receive bounded error events, group them, link releases, and notify one team. The hard boundary is sdk ecosystem, grouping models, tracing, replay, global ingestion, and enterprise operations, plus independent infrastructure and reliable alerting.
What does the Sentry build prompt cover?
The prompt starts with this scope: Accept bounded application-error events, group similar failures, attach release IDs and alert on first-seen or regressed issue groups for one team. Full-product capabilities excluded from the comparison include: SDK ecosystem, grouping models, tracing, replay, global ingestion, and enterprise operations; global probe network; phone and SMS delivery. Follow the implementation plan and its prerequisites before expanding the build.
How do I use the prompt, AGENTS.md and agent skills?
Start with the Sentry prerequisites and stack, then copy the prompt into your coding agent. Save the project rules as AGENTS.md in the project root. Linked skills are optional packages or source instructions for specific tasks; review their current contents and install only those matching the chosen stack. A skill does not supply API credentials or verify the finished app.
How long will this Sentry project take?
The catalogue estimate is multi-day for the limited scope. Setup, integration approvals, debugging, deployment and ongoing maintenance can add time. This is an estimate, not a delivery guarantee.
What would I give up by replacing Sentry?
SDK ecosystem, grouping models, tracing, replay, global ingestion, and enterprise operations; global probe network; phone and SMS delivery; massive retention; advanced incident response and support. People still pay for Sentry because monitoring must continue working during the exact outage it reports, which makes independent infrastructure and alert delivery the real product. The recurring cost buys probe geography, clocks, retries, deduplication, sampling, storage, paging, notification delivery, on-call rules, and its own uptime, not just the visible interface.
What can I use instead of building Sentry?
Exceptionless: A mature error tracker with a strong .NET accent and a real server to maintain. GlitchTip: Sentry's SDK protocol with fewer moving parts and fewer debugging toys. Bugsink: Fifteen thousand hosted errors a month for one user; free self-hosting exists, but it is not open source. Compare all listed options at https://howtovibecodeit.dev/sentry/alternatives. Check each option's license, hosting needs and feature limits.