REST API · Version 1

API Reference

Programmatically create forms, retrieve responses, and generate fields with AI. All from a single, consistent REST API.

Base URLhttps://www.formzen.in/api

Authentication

All API requests (except submitting responses) require your API key in the Authorization header. Generate a key from Settings → API Keys.

Keep your key secret

Never expose it in client-side JavaScript, git repos, or browser requests. Use environment variables.

bash

# Add to every request header
Authorization: Bearer fc_live_your_key_here

# Example
curl https://formzen.in/api/forms \
  -H "Authorization: Bearer fc_live_your_key_here"

Rate limits

Rate limits apply per API key per rolling 60-second window. Every response includes rate limit headers.

Free

—

No API access

Pro

120

requests / minute

Teams

600

requests / minute

http

X-RateLimit-Limit: 120
X-RateLimit-Remaining: 87
X-RateLimit-Reset: 1721234567

# On 429 Too Many Requests:
Retry-After: 12

Errors

All errors return JSON with an error string and optional code.

Status	Meaning
400	Bad request — missing or invalid fields
401	Unauthorized — missing, invalid, or expired API key
403	Forbidden — plan doesn't include this feature, or form/response limit reached
404	Not found — form or resource doesn't exist
409	Conflict — e.g. form not published
429	Rate limited — too many requests, see Retry-After header
500	Server error — retry with exponential backoff

json

{
  "error": "Form limit reached (50 on pro plan). Archive old forms or upgrade.",
  "code": "form_limit_reached",
  "docs": "https://api.formzen.in/docs"
}

Forms

Responses

AI Generation

Field schema

Every field in the fields array follows this structure:

Property	Type	Description
`id`required	string	Unique within the form. e.g. "field_1"
`type`required	string	text \| email \| phone \| number \| textarea \| select \| radio \| checkbox \| date \| rating \| scale \| nps \| heading \| paragraph
`label`required	string	The visible question label
`order`required	integer	Display order, 0-indexed
`pageIndex`	integer	Which page (default: 0)
`description`	string	Help text shown below the label
`placeholder`	string	Placeholder for text inputs
`options`	array	Required for select/radio/checkbox. Each: { id, label, value }
`validation`	object	{ required, minLength, maxLength, min, max }
`properties`	object	Type-specific: { maxRating } for rating, { minLabel, maxLabel } for scale/nps

Formzen API v1 · JSON responses · Bearer auth

Dashboard API Keys