Fintech apps carry the highest-stakes client bundles
Payment/KYC/data-aggregator tokens, webhook secrets — verify none reached the browser. Evidence, not certification.
Your stack, your exposures
Fintech frontends integrate aggressively: payment providers, KYC vendors, account aggregators, notification rails — each shipping configuration that must remain server-bound.
The three leaks we keep finding here
KYC widget keys
Vendor SDKs initialized with environment-scoped tokens granting more than forms need.
Aggregator refresh tokens
Data-pull infrastructure leaking session material into bundles.
Webhook endpoints configured client-side
Ops consoles exposing signing secrets through quickly built admin pages.
The check, time-boxed
Set aside ten minutes and run the audit yourself before trusting anyone’s dashboard, ours included:
- Open the deployed site in a browser you do not usually use, logged out.
- View source, then search the built JavaScript for
eyJ— any hit is a JWT; decode its payload and read the role claim before reacting. - Repeat for provider prefixes:
sk_live_,sk-proj-,sk-ant-,AKIA,xoxb-,SG.,whsec_. - Search for connection schemes —
postgres://,postgresql://,mongodb+srv://— and for-----BEGIN PRIVATE KEY-----. - For every hit, classify: public-by-design (anon keys, publishable keys, Firebase web keys) or genuinely secret. Only the second category is an incident.
That routine works, with two caveats: it only covers what the landing page loads unless you chase route-manifest chunks yourself, and it says nothing about yesterday’s deploy. Automation exists precisely because the check decays.
After the first scan
Calibration matters double here: public-by-design keys informational, privileged ones critical — severity your risk committee can defend.
Boundaries, stated plainly
KeyDrift scans deployed web artifacts — URLs and pasted bundle source. It does not scan mobile binaries, private networks, or repositories; code behind a login is covered by paste mode, and runtime-assembled keys are outside every bundle scanner’s honest reach.
The bigger picture
It helps to name the economics honestly. Fixing this class of leak costs minutes when caught at deploy time and days when caught at invoice time, because by then the credential has been harvested, validated, resold or drained — often all four. Detection latency is the entire game, which is why the monitoring half of KeyDrift exists alongside the scanning half.
How KeyDrift reports this exact finding
When KeyDrift finds this on your deployment, the report shows a masked value (first 8 and last 4 characters only), a salted fingerprint for tracking, the exact chunk filename carrying it, and a severity with written rationale. Public-by-design neighbours — anon keys, publishable keys, Firebase web constants — appear as informational context rather than noise, because knowing what should be there is what makes the real findings credible.
Manual check, step by step
A five-minute version you can run anywhere: view-source on the landing page, copy every src= script URL, fetch each and search the results for eyJ. It misses manifest-only chunks and streamed payloads — which is precisely the gap between "I checked" and "it is clean" — but it catches the loud majority and builds the pattern-recognition that makes scanner output legible.
Close the loop with monitoring
Monitoring closes the loop that one-time verification leaves open. A scheduled scan refetches everything, diffs against history, and fires only on transitions: created, regressed, resolved. Regression alerts matter most here — they fire when a previously fixed finding returns, which in agent-era codebases is less a possibility than a schedule.
What the plans change
- Free $0 — 1 project · daily scans · email alerts · findings always visible.
- Indie $29/mo — 3 projects · hourly · Slack added · 80 chunks per scan.
- Team $89/mo — 15 projects · every 15 minutes · Discord + webhooks · 150 chunks.
- Growth — from $249/mo, quoted display-only until checkout ships.
The constant across every tier: plans limit how much is watched, never what a scan found. Visibility is structural, not promotional — asserted by tests over the entitlements model itself.
Common questions
Compliance framing?
We supply evidence for YOUR reviewers; certification language stays out deliberately.
Run a free scan at keydrift.dev/scan — paste a URL or the bundle source itself, no account. Findings arrive masked, with the exact chunk they live in.