Definitely doable. The admin should not have to customize anything:

1. create your Connected App, once, in an org with a managed package and namespace,
2. bake that exact client_id and secret into the runtime code that you distribute,
3. use Web Server authentication flow or Username-Password flow when calling REST API,

Maybe there is a misunderstanding of how Connected App really operates here. Imagine a Salesforce Package as an analogy. You control the true source code in a Packaging / Release Org but you deploy or install a special instance of it. Similarly with a Connected App:

• you control the Connected App 'definition' including client_id and secret,
• a user allows (or a sysadmin can manage) the connected app 'instance' when it's used.

Does this help?

Definitely doable. The admin should not have to customize anything:

1. create your Connected App, once, in an org with a managed package and namespace,
2. bake that exact client_id into the runtime code that you distribute,
3. use Web Server authentication flow or Username-Password flow when calling REST API,

Maybe there is a misunderstanding of how Connected App really operates here. Imagine a Salesforce Package as an analogy. You control the true source code in a Packaging / Release Org but you deploy or install a special instance of it. Similarly with a Connected App:

• you control the Connected App 'definition' including client_id and secret,
• a user allows (or a sysadmin can manage) the connected app 'instance' when it's used.

Does this help?

Definitely doable. The admin should not have to customize anything:

1. create your Connected App, once, in an org with a managed package and namespace,
2. bake that exact client_id and secret into the runtime code that you distribute,
3. use Web Server authentication flow or Username-Password flow when calling REST API,

Maybe there is a misunderstanding of how Connected App really operates here. Imagine a Salesforce Package as an analogy. You control the true source code in a Packaging / Release Org but you deploy or install a special instance of it. Similarly with a Connected App:

• you control the Connected App definition including client_id and secret,
• a user allows (or a sysadmin can manage) the connected app instance when it's used.

Does this help?

Definitely doable. The admin should not have to customize anything:

1. create your Connected App, once, in an org with a managed package and namespace,
2. bake that exact client_id and secret into the runtime code that you distribute,
3. use Web Server authentication flow or Username-Password flow when calling REST API,

Maybe there is a misunderstanding of how Connected App really operates here. Imagine a Salesforce Package as an analogy. You control the true source code in a Packaging / Release Org but you deploy or install a special instance of it. Similarly with a Connected App:

• you control the Connected App 'definition' including client_id and secret,
• a user allows (or a sysadmin can manage) the connected app 'instance' when it's used.

Does this help?