Justy: Okay, so LangChain’s saying the thing that matters for agents is the harness.
Cody: That’s… not what matters.
Justy: I know, I know, but hear me out— their whole point is the harness is the scaffolding that decides if the agent’s actually useful.
Cody: Right.
Justy: And they’re pitching create_agent as this minimal primitive where you just hand it a model, some tools, a prompt, and boom— working agent.
Cody: Which is fine. But then they immediately pivot to middleware.
Justy: Yeah, because that’s where the magic happens.
Cody: That’s where the happens.
Justy: Cody, you’re doing the thing where you see a new abstraction and assume it’s hiding a mess.
Cody: Because it .
Justy: Okay, but let’s say I’m building an agent that needs to pull from three different proprietary APIs, enforce some custom business rules, and log every single tool call for compliance.
Cody: Sure.
Justy: Deep Agents or Claude’s SDK would either not support that or force me to hack around their defaults. create_agent lets me slot in middleware for all of that— setup, teardown, state, stream handlers— without rewriting the whole loop.
Cody: Or you could just use the pre-assembled stack and save yourself six months of debugging edge cases in your custom middleware.
Justy: But what if the pre-assembled stack do what I need?
Cody: Then you’re probably building something weird enough that you be writing custom middleware.
Justy: There it is.
Cody: I’m not wrong.
Justy: No, but you’re also missing the point. This isn’t for the average builder. This is for the teams that that control— internal tooling, niche workflows, stuff that doesn’t fit the opinionated stacks.
Cody: Mm-hm.
Justy: And the middleware approach is actually pretty elegant— hooks for before and after model calls, tool calls, startup, teardown. It’s composable. You can swap in logic for dynamic model switching, prompt adjustments, even custom state tracking.
Cody: Composable, sure. But it’s also layer to maintain. And now you’re not just debugging your agent, you’re debugging your middleware your agent.
Justy: Yeah, but that’s the trade-off for flexibility. And for the right use case, it’s worth it.
Cody: For the right , maybe. This feels like a power-user feature masquerading as a general-purpose solution.
Justy: I mean… isn’t that how most good tools start? Someone builds a thing for their own weird needs, and then it turns out other people have those needs too.
Cody: That is SUCH an Exploring Next take.
Justy: Oh, come on. You can’t tell me you haven’t seen this pattern a hundred times.
Cody: I’ve seen it. I’ve also seen a hundred teams drown in their own abstractions.
Justy: Okay, but let’s say I’m wrong. Let’s say most people just use Deep Agents or the Claude SDK. What’s the harm in create_agent existing?
Cody: No harm. It’s fine. It’s just… not the revolution they’re making it sound like.
Justy: It’s not a revolution for the people who need it.
Cody: Alright, fine. For the teams with the chops and the weird requirements, this is a solid step forward.
Justy: And for everyone else?
Cody: Stick to the pre-assembled harnesses and save your sanity.
Cody: I’ll set a reminder. And when I’m right, you owe me coffee.
Justy: And when right, you’re buying the first round.