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Wait was it? HATEOAS is all about hypermedia, which means there must be a human in the loop being presented the rendered hypermedia. MCP seems like it's meant t

by mort96 1y ago

Wait was it? HATEOAS is all about hypermedia, which means there must be a human in the loop being presented the rendered hypermedia. MCP seems like it's meant to be for machine<->machine communication, not human<->machine

layer8 1y ago
I agree that HATEOAS never made sense without a human in the loop, although I also have never seen it be described as such. IMO that’s an important reason why it never gained useful traction. There is a confused history where Roy Fielding described REST, then people applied some of that to JSON HTTP APIs, designating those as REST APIs, then Roy Fielding said “no you have to do HATEOAS to achieve what I meant by REST”, then some people tried to make their REST APIs conform to HATEOAS, all the while that change was of no use to REST clients. But now with AI it actually can make sense, because the AI is able to dynamically interpret the hypermedia content similar to a human.
NomDePlum 1y ago
My understanding was that the discoverable part of HATEAOS was meant for machine to machine. Actually all of REST is machine to machine except in very trivial situations. Not sure I'm understanding your point in hypermedia means there is human in the loop. Can you expand?
- renerick 1y ago
  H in HATEOAS stands for "hypermedia". Hypermedia is a type of document that includes hypermedia controls, which are presented by the hypermedia client to a user for interaction. It's the user who makes decision what controls to interact with. For example, when I'm writing this comment, HN server gave a hypermedia document, which contains your comment, a textarea input and a button to submit my reply, and me, the human in the loop, decides what to put in it the input and when to press the button. A machine can't do that on its own (but LLMs potentially can), so a user is required. That also means that JSON APIs meant for purely machine to machine interactions, commonly referred to as REST, can't be considered HATEOAS (and REST) due to absence of hypermedia controls. Further reading: - https://htmx.org/essays/how-did-rest-come-to-mean-the-opposite-of-rest/ https://htmx.org/essays/how-did-rest-come-to-mean-the-opposi... - https://htmx.org/essays/hateoas/ https://htmx.org/essays/hateoas/
  - NomDePlum 1y ago
    So that's not my understanding. Hypermedia, as I understand it, are embedded links in responses that present possible forward actions. They are structured in a way that machine program could parse and use. I don't believe it requires human-in-the-loop, although that is of course possible.
    - recursivedoubts 1y ago
      HTML is a hypermedia format, the most widely used, and it's designed mainly for human consumption. Machines parsing and using something is too broad an idea to engage with meaningfully: browsers parse HTML and do something with it: they present it to humans to select actions (i.e. hypermedia controls) to perform. Your understanding is incorrect, the links above will explain it. HATEOAS (and REST, which is a superset of HATEOAS) requires a consumer to have agency to make any sense (see https://intercoolerjs.org/2016/05/08/hatoeas-is-for-humans.html https://intercoolerjs.org/2016/05/08/hatoeas-is-for-humans.h...) MCP could profitably explore adding hypermedia controls to the system, would be interesting to see if agentic MCP APIs are able to self-organize: https://x.com/htmx_org/status/1938250320817361063 https://x.com/htmx_org/status/1938250320817361063
      - NomDePlum 1y ago
        I've programmed machines to use those links so I'm pretty certain machines can use it. I've never heard of the HTML variation but so will have a look at those links.
        recursivedoubts 1y ago
        how did the machines you programmed react to new and novel links/actions in the response?
        NomDePlum 1y ago
        New are fine, Novel need catered for. I have left a fuller explanation to a sibling comment.
- mort96 1y ago
  If you have machine <-> machine interaction, why would you use HTML with forms and buttons and text inputs etc? Wouldn't JSON or something else (even XML) make more sense?
chriswarbo 1y ago
Hypermedia isn't just for human consumption. Back in the 90s, the Web was going to be crawled by "User Agents": software performing tasks on behalf of people (say, finding good deals on certain items; or whatever). Web browsers (human-driven interfaces) were the most common User Agent, but ended up being a lowest-common-denominator; the only other User Agents to get any widespread support were Google crawlers.

by mort96 1y ago

layer8 1y ago

I agree that HATEOAS never made sense without a human in the loop, although I also have never seen it be described as such. IMO that’s an important reason why it never gained useful traction. There is a confused history where Roy Fielding described REST, then people applied some of that to JSON HTTP APIs, designating those as REST APIs, then Roy Fielding said “no you have to do HATEOAS to achieve what I meant by REST”, then some people tried to make their REST APIs conform to HATEOAS, all the while that change was of no use to REST clients. But now with AI it actually can make sense, because the AI is able to dynamically interpret the hypermedia content similar to a human.

NomDePlum 1y ago

My understanding was that the discoverable part of HATEAOS was meant for machine to machine. Actually all of REST is machine to machine except in very trivial situations. Not sure I'm understanding your point in hypermedia means there is human in the loop. Can you expand?

renerick 1y ago
H in HATEOAS stands for "hypermedia". Hypermedia is a type of document that includes hypermedia controls, which are presented by the hypermedia client to a user for interaction. It's the user who makes decision what controls to interact with. For example, when I'm writing this comment, HN server gave a hypermedia document, which contains your comment, a textarea input and a button to submit my reply, and me, the human in the loop, decides what to put in it the input and when to press the button. A machine can't do that on its own (but LLMs potentially can), so a user is required. That also means that JSON APIs meant for purely machine to machine interactions, commonly referred to as REST, can't be considered HATEOAS (and REST) due to absence of hypermedia controls. Further reading: - https://htmx.org/essays/how-did-rest-come-to-mean-the-opposite-of-rest/ https://htmx.org/essays/how-did-rest-come-to-mean-the-opposi... - https://htmx.org/essays/hateoas/ https://htmx.org/essays/hateoas/
- NomDePlum 1y ago
  So that's not my understanding. Hypermedia, as I understand it, are embedded links in responses that present possible forward actions. They are structured in a way that machine program could parse and use. I don't believe it requires human-in-the-loop, although that is of course possible.
  - recursivedoubts 1y ago
    HTML is a hypermedia format, the most widely used, and it's designed mainly for human consumption. Machines parsing and using something is too broad an idea to engage with meaningfully: browsers parse HTML and do something with it: they present it to humans to select actions (i.e. hypermedia controls) to perform. Your understanding is incorrect, the links above will explain it. HATEOAS (and REST, which is a superset of HATEOAS) requires a consumer to have agency to make any sense (see https://intercoolerjs.org/2016/05/08/hatoeas-is-for-humans.html https://intercoolerjs.org/2016/05/08/hatoeas-is-for-humans.h...) MCP could profitably explore adding hypermedia controls to the system, would be interesting to see if agentic MCP APIs are able to self-organize: https://x.com/htmx_org/status/1938250320817361063 https://x.com/htmx_org/status/1938250320817361063
    - NomDePlum 1y ago
      I've programmed machines to use those links so I'm pretty certain machines can use it. I've never heard of the HTML variation but so will have a look at those links.
      - recursivedoubts 1y ago
        how did the machines you programmed react to new and novel links/actions in the response?
        NomDePlum 1y ago
        New are fine, Novel need catered for. I have left a fuller explanation to a sibling comment.
mort96 1y ago
If you have machine <-> machine interaction, why would you use HTML with forms and buttons and text inputs etc? Wouldn't JSON or something else (even XML) make more sense?

chriswarbo 1y ago

Hypermedia isn't just for human consumption. Back in the 90s, the Web was going to be crawled by "User Agents": software performing tasks on behalf of people (say, finding good deals on certain items; or whatever). Web browsers (human-driven interfaces) were the most common User Agent, but ended up being a lowest-common-denominator; the only other User Agents to get any widespread support were Google crawlers.