J. Edward Hackett offers some good general advice above. Given that assessment requirements differ a bit from institution to institution, it might be worth asking the assessment regime there whether there are good models for assessment of program outcomes in adjacent disciplines at your institution. Sometimes colleagues in other departments have really good tools that are not too difficult to adapt. Meanwhile, one of the best philosophy-specific write-ups of assessment practices that I’ve read is: Wright, Charles W., and Abraham Lauer. “Measuring the Sublime: Assessing Student Learning in Philosophy.” Teaching Philosophy 35, no. 4 (December 2012): 383-409.

As for the idea of utilizing something like a comprehensive exam to measure student competency in any area of philosophical knowledge (history of philosophy or any other area), others below have commented on the GRE subject test in Philosophy, which was disbanded sometime in the last 25 years. My memory is hazy, but I believe that it still existed in the mid-90s when I applied to graduate programs in Philosophy, but by then I don’t think many (if any) programs required it anyway. I am certain that I did not take it. I’ve looked for this information in the obvious places one might look for it, but haven’t been able to find reliable information about when ETS discontinued it officially.

As for the question of the role such instruments might play in undergraduate outcome assessment, some of the other commenters below have suggested that it might be possible or desirable to develop a good test for knowledge of the history of philosophy. This might be true, but FWIW, I am skeptical of the value of any kind of nationally-validated instrument for several reasons, among them:

1. Different philosophy programs likely emphasize different implicit or explicitly stated understandings of the scope of historical knowledge that they expect undergraduates to possess. Some programs might place more or less emphasis on medieval philosophy and/or various non-European traditions, for instance. You could, of course, test students with the same instruments that others use and then set benchmarks for student performance that are specific to your own program goals, but this might not be an educationally rewarding experience for your students.
2. By contrast with comprehensive exams of the sort mentioned above, in general assessments that are tied to specific coursework are more reliable in terms of giving a picture not only of what students are learning in a given course, but also what they are learning at some specific point in their degree progression in a particular program. So even if there were some sort of tool available for use by various programs, it would still function best if it were embedded as an assignment in some particular course in a degree program — perhaps if nowhere else, then as part of a capstone requirement. This might be possible in some cases, but, in my experience, it is generally easier to develop assessment tools based on existing assignments than to ask instructors to adopt or develop entirely new assignments that don’t fit well within their own personal conceptions of what their courses and assignments should look like. Even if the assessment results would be better with an entirely new assignment, expecting instructors to adopt and utilize new instruments is generally much more difficult (and sometimes counterproductive) than simply asking for minor modifications of an existing assignment (or simply asking faculty to save student artifacts for an assessment committee to evaluate independently) to facilitate collection of assessment data.
3. In addition to the preceding points, presumably you want to assess multiple outcomes in your philosophy program. If so, then, as J. Edward Hackett observes, rather than using a test to assess knowledge of the history of philosophy, you might want to identify (or modify) an existing assignment in such a way as to allow you to assess more than one outcome at the same time using the same assignment. For instance, if you have an upper level history sequence, and your colleagues are all willing to adopt similar sorts of assignments as key assignments in those courses, then you could conceivably assess disciplinary writing abilities, research methodology, and historical knowledge using similar assignments across multiple courses.
4. Above all, if you are willing to put the time into it, I’d recommend developing a senior capstone course with a portfolio requirement. The portfolio would include work from prior courses as well as reflections on their progress in the program, and perhaps assignments helping focus on future goals (writing samples and personal statements for graduate school, internship reflection essays, senior capstone project, etc.) all of these could be used to assess multiple outcomes precisely where the data is most meaningful for assessing your graduates’ competencies. You could certainly include some sort of comprehensive assessment of knowledge in such a course. Or even just indirectly assess it by surveying students to ask them about the areas of philosophy they believe the received the most/least amount of education in. That would be revealing information even if you also want to have some tools to directly assess their learning in other ways.

not only can you get your objectives and outcomes from gpt, you can get your assessment rubric too. complete. nicely formatted and everything. now if somebody were to make an interface where i just upload the papers and the rubric ….