Errors, traces, and traffic — in one place.

Marsad streams exceptions, network requests, performance traces, Web Vitals and cookieless analytics from your Next.js and Expo apps — grouped, symbolicated, and alertable. One drop-in SDK, no consent banner — and an MCP server so Claude can debug it with you.

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Free plan · no credit card · 2-minute setup

acme-web · productionlive

TypeError: Cannot read properties of undefinedapp/checkout/CartSummary.tsx · 1,204 eventserror
Slow resource: GET /api/orders took 4210mslib/api/client.ts · 203 eventswarn
Unhandled Promise Rejection: Failed to fetchlib/api/client.ts · 311 eventserror
pageload · /checkouttrace 8f2a1c · 1.9sinfo
ChunkLoadError: Loading chunk 23 failedwebpack/runtime · 137 eventserror

Built for the stack you already shipNext.jsExpoReact NativeViteNodeTypeScript

Everything you need to see what’s happening

From the first exception to the alert in your inbox — errors, traces, traffic and release health, for web and mobile.

Error tracking that groups itself

Exceptions and unhandled rejections are captured, deduplicated into issues, and ranked by impact — with full stack traces and the breadcrumbs that led there.

Next.js error tracking →

Traces you can read

Pageloads, navigations, requests and assets become one trace per page, opened as a waterfall — and a traceparent header carries it into your Next.js backend.

Expo & React Native →

Traffic, without the cookie banner

Page views, top pages, referrers, UTM campaigns, devices, countries and live visitors — on the web automatically, and on Expo with one hook. Counted with a rotating hash, so there’s nothing to consent to.

Cookieless analytics for Next.js →

Alerts that find you

Rules for new issues, event volume or error rate — delivered to Slack, email, a webhook or straight into Linear as a task, with dedupe and per-rule cooldowns.

How Marsad compares to Sentry →

Source-mapped stacks: Debug IDs match each build to its source map automatically — minified web and Hermes frames resolve to your real files and lines, with no release bookkeeping.
Custom metrics: Counters, distributions and gauges via metrics.increment / distribution / gauge — aggregated into count, sum and p95.
Screenshots on errors: Opt in and Marsad attaches a screenshot of the broken screen to the issue, so you see exactly what the user saw.
Crash-free rate: Sessions are tracked on every app start and marked crashed on an unhandled error — release health at a glance.
Native mobile crashes (beta): iOS signals, NSException and Swift traps, Android JVM crashes, ANRs and C/C++ crashes — sent on the next launch, even when the app dies before JavaScript starts.
Web Vitals: LCP, CLS, INP, FCP and TTFB captured on the web with zero config, shown as a p75 card on your Overview.
Tags and filters: Attach indexed tags like plan, region or tenant, then slice your issues by them from chips on every issue.
Feedback tied to the error: Collect a user’s report and link it to the exact issue with the same reference code they saw.
Offline-resilient delivery: The event queue is persisted and retried with backoff, so errors survive reloads, flaky networks and crashes.
Shareable reference codes: Every captured error gets a short code like MAR-K7P2QX9M — show it to users, then jump straight to it from ⌘K.
Logs and sessions: Filter logs by level, search the message, and jump from a crashed session to the error that killed it.
Affected users: Every event can carry a user, so an issue shows who hit it — and a user page shows everything that broke for them.
Release health: Releases are detected from your CI commit SHA and tracked with their events, issues and first/last-seen.
Triage, not just a feed: Resolve, ignore or reopen, assign to a teammate, discuss in threaded comments — or push to Linear in one click.
Every project, one place: Unlimited projects on paid plans, switched instantly. Your web and mobile apps, side by side.

Live in three steps

Install, then stop guessing. There is no agent to run and no infrastructure to stand up.

Install the SDK

Add the package and call init() with your project key. One line for Next.js, one for Expo.

npm install @marsadco/sdk

Events stream in

Errors, rejections and network calls are captured automatically — each one carries runtime context and the breadcrumbs that led there.

Triage and fix

Jump from a grouped issue to the exact stack frame, see the breadcrumbs, ship the fix.

Let Claude read your errors

Marsad ships a remote MCP server — the open standard AI assistants use to reach real systems. Connect it once and your assistant works your data directly.

Included on every plan.

One URL, no install

Add the endpoint in Claude’s connector settings, or one command in Claude Code. OAuth handles the rest.

Scoped to what you approve

You pick the organization and the permissions on a consent screen — read-only by default, triage opt-in. Revoke any time.

Fourteen tools

Issues, events, stack traces, transactions, traces, releases, logs, affected users — plus resolve, assign and comment.

Connect your assistant

claude mcp add --transport http marsad \
  https://www.marsad.space/api/mcp

youWhat’s the worst new issue in checkout since Friday?

claudeTypeError in CartSummary — 1,204 events from 335 users, first seen in release 2.14.0. The stack points at line 42 of cart-summary.tsx, where total is read before the cart resolves.

youAssign it to me and leave a note.

claudeAssigned, and I added the trace link as a comment.