NOTE:
This is the documentation for the websocket channel sec:497_filings.
Websocket access for personal use is only available through the Advanced plan.
You can find fully-functional examples that stream data from many channels here:
Connect to the websocket URI:
wss://api.unusualwhales.com/socket?token=<YOUR_API_TOKEN>
then join the sec:497_filings channel.
Each message carries one filing made under Securities Act Rule 497: prospectus and summary
material that a fund or securities issuer publishes. Forms 497, 497J and 497K arrive on
this one channel. Use type to tell them apart.
Delivery characteristics
- Updates are event driven. The channel stays silent until a Rule 497 filing is
processed. There is no heartbeat and no fixed schedule.
- A filing with several issuers is sent once per issuer. The messages share
accession_no and differ in issuer, issuer_cik, html_url and filing_link.
- Messages are not deduplicated. If the same filing is published twice, you receive it
twice. Identify a message by
accession_no and issuer_cik together.
- The channel sends nothing when you join. Messages sent while you are disconnected are
not replayed.
- The channel is global only. It covers every issuer at once. A join on
sec:497_filings:<TICKER> is answered with an {"error": "..."} frame.
Payload format:
Field reference
Every field is present in every message. A value the filing does not provide is sent as an
empty string, never as null.
The payload has the fields of the Kafka message
Form497, published to the topic
sec-filings under the key form497. Last modified on October 1, 2026
