FYERS enforces a subscription cap on its Market Data WebSocket API v3 to maintain stable real-time data delivery across all user applications. This limit ensures efficient performance during high-frequency usage and concurrent client loads.
You can subscribe to a maximum of 5000 unique symbols concurrently through the Market Data WebSocket in API v3. This limit applies per API key and includes all types of instruments—such as equities, indices, and derivatives—across supported exchanges.
Note: Only unique symbols are counted. Subscribing to the same symbol multiple times does not affect the total.
Scenario | Outcome |
---|---|
You attempt to subscribe to more than 5000 symbols | The WebSocket will reject any symbols beyond the allowed cap. |
You need access to more than 5000 symbols | You must dynamically manage your subscriptions—unsubscribe symbols not currently in use. |
You’re unsure how many symbols are active | You’ll need to track subscriptions in your application. FYERS does not return the active symbol list. |
Last updated: 29 Aug 2025