SEC Form S-3 API

Form S-3 API (Shelf Registrations)

Watch for capital raises. The Form S-3 API surfaces shelf and follow-on registration statements from companies that already report, as structured JSON.

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JSON responsesOpenAPI documentedcURL / Python / JS / GoFree tier available

What is Form S-3?

Form S-3 is the short-form registration statement available to established public companies. It is commonly used for shelf registrations and follow-on offerings.

An S-3 signals that a company may raise capital — issuing shares or debt off the shelf — which is material for dilution and balance-sheet analysis.

The Finsider Form S-3 API indexes these registrations so you can anticipate offerings and monitor capital-markets activity.

Fetch Form S-3 filings

List recent Form S-3 filings, filterable by company, ticker, and date.

cURLPythonJavaScriptGo

curl -s "https://api.secapi.dev/v1/filings?formTypes=S-3&limit=20" \
  -H "x-api-key: $SECAPI_KEY"

import requests

resp = requests.get(
    "https://api.secapi.dev/v1/filings?formTypes=S-3&limit=20",
    headers={"x-api-key": "YOUR_API_KEY"},
    timeout=30,
)
resp.raise_for_status()
data = resp.json()
print(data)

const res = await fetch("https://api.secapi.dev/v1/filings?formTypes=S-3&limit=20", {
  method: "GET",
  headers: { "x-api-key": process.env.SECAPI_KEY },
});
if (!res.ok) throw new Error(`HTTP ${res.status}`);
const data = await res.json();
console.log(data);

package main

import (
	"fmt"
	"io"
	"log"
	"net/http"
	"os"
)

func main() {
	req, _ := http.NewRequest("GET", "https://api.secapi.dev/v1/filings?formTypes=S-3&limit=20", nil)
	req.Header.Set("x-api-key", os.Getenv("SECAPI_KEY"))

	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		log.Fatal(err)
	}
	defer resp.Body.Close()

	body, _ := io.ReadAll(resp.Body)
	fmt.Println(string(body))
}

Who files Form S-3?

Filer	Requirement
Established issuers	Companies meeting S-3 eligibility
Shelf registrations	Register securities for future sale
Follow-on offerings	Secondary equity and debt raises
Related forms	Final terms appear in a 424B prospectus

Deadlines & coverage

Aspect	Detail
Trigger	Filed to register securities off the shelf
Amendments	S-3/A and 424B prospectus supplements
Eligibility	Requires a public float / reporting history
Availability	Indexed within minutes of acceptance

Key data fields

A sample of the structured fields returned for Form S-3 data.

Field	Description
`companyName` / `cik`	Registrant identity
`formType`	`S-3` / `S-3/A`
`filingDate`	Date the registration was filed
`documents`	Registration statement and exhibits
`accessionNumber`	Unique SEC identifier

Related API endpoints

Deep-link into the interactive reference to try these live.

GET /v1/filings List filings Search and page every SEC filing, filtered by form type, company, ticker, and date. GET /v1/filings/{cik}/{accessionNumber}/documents List filing documents and exhibits Enumerate every document and exhibit attached to a filing, with direct URLs. GET /v1/entities/{identifier}/filings List a company’s filings Return every filing for a company by ticker or CIK.

Frequently asked questions

What is the Form S-3 API?

An endpoint that returns SEC Form S-3 short-form and shelf registration statements as structured JSON.

Why does an S-3 matter for investors?

An S-3 shelf registration signals a company may raise capital, which can mean future dilution — useful to monitor for balance-sheet and ownership analysis.

Build with the Form S-3 API

Create a free account, grab an API key, and make your first request in under a minute.

Get your API key Browse the API reference