Why are my requests to /iserver endpoints failing, while others succeed?

Q: Why are my requests to /iserver endpoints failing, while others succeed?

Access to endpoints containing / iserver , which are used to place orders and receive market data, require a brokerage session. The endpoint /iserver/auth/status will return the status of your Web API brokerage session via its "authenticated" field. A response containing "authenticated": "false" indicates that no Web API brokerage session currently exists for the requesting username. The endpoint /iserver/auth/ssodh/init?publish=true&compete=true may be used to attempt to open a brokerage session for your username. Note that only one brokerage session maybe exist for a given username at any time, and the compete=true query parameter in the above request will terminate a preexisting brokerage session for your username, replacing it with a newly created Web API brokerage session.

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Accepted Answer

Access to endpoints containing /iserver, which are used to place orders and receive market data, require a brokerage session. The endpoint /iserver/auth/status will return the status of your Web API brokerage session via its "authenticated" field. A response containing "authenticated": "false" indicates that no Web API brokerage session currently exists for the requesting username. The endpoint /iserver/auth/ssodh/init?publish=true&compete=true may be used to attempt to open a brokerage session for your username. Note that only one brokerage session maybe exist for a given username at any time, and the compete=true query parameter in the above request will terminate a preexisting brokerage session for your username, replacing it with a newly created Web API brokerage session.