01
Over-fetch and large payloads
Fields not read in observed sessions, and responses larger than the page needs — with the evidence to investigate a smaller payload.
Frontend API intelligence001 — API INTELLIGENCE
See your API.
Find the waste.
How much of your response does your frontend actually use? Find unread fields, repeated calls and slow endpoints with one script. Go from evidence to a concrete next step.
No credit card. 50,000 responses a month free.01 / CAPTURE02 / UNDERSTAND
From noise to signal
Move your pointer to explore · Illustrative visualization
AT HOME IN YOUR STACK
Next.jsReactVuefetchaxiosTanStack Query
Keep exploring01 / The missing visibilitySent by your API.
Sent by your API.
Actually used by your app.
A successful response is only half the story. Explore which fields your frontend reads — and what is left behind.
RESPONSE FIELDSJSON
Select the fields your frontend reads. Watch the analysis change.
THE OTHER SIDE OF THE RESPONSE
63%
of fields go unread.
3 of 8 fields read by the example frontend.
Room for a leaner response
Consider a smaller response for this view. Review usage across real sessions before removing fields.
02 / Features
Small signals. Big opportunities.
Every finding comes from real traffic in your app, with the requests behind it and the code that made them.
02
Slow endpoints and errors
Investigate endpoints that cross your project’s latency threshold and elevated error rates, backed by enough samples.
03
Duplicates, refetch and retry storms
Spot duplicate calls, frequent refetches and retry storms after failed requests.
04
Missing pagination
A thousand-item list downloaded when the page only ever reads the first twenty.
05
Credential-like fields
Passwords, tokens and keys sent to the browser, flagged whether or not the page reads them.
06
Call sites and releases
The component and line that made each request, resolved through your source maps, and the release a finding first appeared in.
Each layer reveals what comes next.
API HERON / DATA FLOW01 / 03
Illustrative product flow · Select a layer to explore
01 / REAL TRAFFIC
Follow the request.
The SDK records the shape, size and timing of JSON responses your app receives. See which page called which endpoint.
↳Endpoint · timing · size · page
02 / ACTUAL USAGE
Connect what arrives to what gets used.
Inspect the fields your code reads alongside the response shape. Investigate unread fields and repeated calls with evidence from observed sessions.
↳Field usage · sessions · findings
03 / A CONCRETE NEXT STEP
Make the change where it matters.
Move from a finding to its call site. Review steps for Frontend, Backend, SQL and DevOps, then check new traffic after shipping your change.
↳Call site · solution steps · release
INSTALLATION
One project. One script. You’re ready.
Create a free account and add your app’s address. Copy the snippet with your project key from setup, then use your app’s real flows.
Explore the free plan ↗index.html
<script
src="https://app.apiheron.com/sdk.js"
data-key="YOUR_PROJECT_KEY"
></script>Replace YOUR_PROJECT_KEY with the key from your project.
The SDK records the shape of responses (field paths, item counts, size, timing) and which fields your code reads. It never records response values, and query values are hashed in the browser.
Don’t just spot the problem. Know your next move.
ILLUSTRATIVE OVER-FETCH FIX
Ask for exactly what the view needs.
Use a purpose-built response for the product card. Coordinate the smaller endpoint with your backend; filtering after fetch won’t reduce transferred bytes.
Example implementation
const products = await fetch(
"/api/products?view=card"
).then((response) => response.json());Pricing
Quotas count captured API responses per calendar month; when one runs out, capture pauses until the next month and nothing extra is billed.
Free
$0/ month
For trying apiheron on a side project or a single app.
- 50,000 responses a month
- 7-day data retention
- Every finding kind and the Solutions tab
- Source maps and release tracking
- 1 member, 2 projects (one app's dev and prod)
TeamBuilt for teams
$29/ month
$290 per year
For teams profiling their production and staging apps.
- 1,000,000 responses a month
- 30-day data retention
- Every finding kind and the Solutions tab
- Source maps and release tracking
- Unlimited projects and team members
- Roles, invitations and audit log
- Switch plans or cancel from the customer portal
Business
$99/ month
$990 per year
For companies watching several busy apps with a longer history.
- 5,000,000 responses a month
- 90-day data retention
- Every finding kind and the Solutions tab
- Source maps and release tracking
- Unlimited projects and team members
- Roles, invitations and audit log
- Switch plans or cancel from the customer portal
- Priority email support
Enterprise
Custom
For organizations that need high volume, a custom contract or their own infrastructure.
- Response volume sized to you
- Retention sized to you
- Every finding kind and the Solutions tab
- Source maps and release tracking
- Unlimited projects and team members
- Roles, invitations and audit log
- Annual contract and invoicing
- Option to run it on your own servers
- Priority email support
Upgrade from Workspace after signing up. Payments, invoices and taxes are handled by Polar.
04 / FAQ
A little more clarity.
A few things to know before your first capture.
Does apiheron store my response values?+
No. The SDK records response shapes: field paths, item counts, size and timing, plus which fields your code reads. Response values are not recorded; query values are hashed in the browser.
Will it work with my frontend?+
apiheron observes JSON API traffic with fetch and axios, with a TanStack Query integration. Add the SDK to your app; Next.js, Vite and plain HTML installation snippets are available during setup.
What happens when I reach my plan limit?+
Capture pauses until the next calendar month. There are no automatic overage charges. You can upgrade from your workspace if you need more capacity.
Can I try it without a credit card?+
Yes. Create an account, add your project and install the script on the free plan.