The Agent SDK
cursor.com
cursor.com
The web front end (chat UI) that the business actually interacts with often needs to be adapted to the domain. We have tried to use the various chat UIs out of the box with customization on top and all of this has failed spectacularly. There are cases where we need to pop into an inline approval flow with custom elements and controller actions. How do you hook the existing platforms for this? There zero path. MCP can give you an information channel, but it does not enforce the required UI/UX flow for certain tool calls. We could either compromise on UX or rebuild chatgpt.com from scratch. We ultimately went with the latter.
"Deploy" section of that article makes the difference.
Every week we'd build a new thing in our agent workflow and then Google's ADK the following week would have support for something we could have used instead of rolling our own.
Reading this release makes me wonder what makes it special, nothing sticks out from the press release.
But I agree, the churn is real, people are starting to throw around the term software factory at the management level and I fear big efforts there will be outdated by the time they finish, even with coding agents support.
The cheaper agents never really matter, because the Max subscription costs me $100 and that is less than an hour of pay. In some cases the customer even pays for the subscription.
But I do love the idea of being able to use Pi or OpenCode. I am a heavy terminal user, and used Vim/Tmux/Lazygit-types of workflows before coding agents were in the terminal, so I do love customizability and portability. Right now there is just too much ground-shift to take part in it. Better to wait it out.
I make one (https://github.com/juggler-ai/juggler) and it'll auto-detect and use your claude CLI. I use that claude plan for 90% of my work, plus a bit of GPT, I just prefer to do it inside a nicer, less locked-in environment than claude.
There's really no moat around proprietary closed harnesses, it's trivial to jump between them, but people need to be aware that it's possible!
Several perhaps, but you definitely aren't using all coding harnesses actively.
I have used cc, oc, pi, shelley and codex fwiw
They have what seems good prices, but then you realize the "Pro" plan only includes "Pro" models, not "Advanced" and there is no list of what is what.
So you Google and find the Reddit conversations where it turns out hardly anything is included.
Building an exceptional harness requires exceptional understanding of the technology you are harnessing.
Ant is building Claude Code in a place of frontier knowledge and advancement - everything surrounding the tool at Anthropic is something that does not exist within any "open source" organization. OC has recruited exceptional developer and new-media talent, but they have largely developed from a "catchup/copy" and designer-led process, and have consistently been behind in terms of capabilities and/or have misaligned implementation due to what I would classify as disadvantages of not understanding the underlying technology fully. I think this has led to a lot of unintended bloat - maintaining a plugin for it has been consistently very head-scratching experience.
- Pi was a refreshing welcome to the OSS arena with thoughtful design to enable simplicity and ecosystem-based development
In October 2026 - Claude Code feels further stretched ahead. The orchestration/projects model you get with sub agents either in the cloud/remote or local is the strongest capability I have experienced in awhile. Beyond the model intelligence the harness has been consistently refined and now includes things like Mods for robust customization. OC is pushing through big milestone release, not advancing on the front in terms of agentic engineering ux. Who came up with MCP, Slack/Claude Tag interface paradigm (less about slack), dynamic workflows, durable subagents, agent-to-agent communication across the harness, etc
We build a desktop app on top of the SDK, so I've spent a lot of time on that page.
Weirdly I know for sure there was an article behind that first link earlier today but now it's showing no body, just the update boxes. The second doc link is quite clear though.
They spend more time trying to figure out how to put more agents into their "process" and solve any problems it creates with more agents than just doing a general claude run and tweaking it themselves with the skills they built over their career ostensibly.
Cracks me up watching engineers completely degrade themselves by saying that a "team" of "agents" should just be let loose on a task and create 10,000+ line PRs that no human will ever read, then deploy it to production and run code no human has seen or understands....like, stop degrading yourself to prop up these companies bleeding money....it is a tool, it is powerful, it isn't an engineer though and you are, it isn't smart and you are, don't intentionally argue for your own replacement by a fucking corporate chatbot.
If I had to work at a company that thought they could do software that way I would refuse to join the on-call rotation....if that fucking shit is so much better than me that we need to rush un-reviewed shit to production then I'm sure it is also so much better than me and it can manage oncall for nights and weekends at least...unassisted. Watch how many of these zealots change their tune when you tell them they should hand over on-call 24/7 in production to bots and not even put people in a pager rotation or page them. Suddenly real people are needed to fix the software we were too stupid to write but the bot - that did write it - is too fucking stupid to manage?
make it make sense.
You can get massive productivity increases with these tools while still using manual-mode only, reading the code as it is generated via the diffs, yell at it when it does boneheaded shit (which it 100% will), and doing narrow-scoped tickets/PRs that are reviewable by a human being just like in the before times. What is the need to go faster than that and essentially just tie the entire product of your company to what some other company's bot chooses to shit out to you that day?
More and more harnesses are headed this way, there are two notable holdouts.
2. Lots of people are used to Claude Code's interface/commands/etc. and don't feel like paying the cost of learning something new. The benefits would have to outweigh those switching costs, and it's unclear that they do.
3. Claude Code already works with your Claude MAX subscription[0], which gives you an incredible amount of usage of the top-tier models for cheap, which can't be matched by any open-source options. And most people won't exhaust this usage, so they have no real need to use open-source models.
4. Although it's hard to 100% confirm this, there's reason to believe that Claude itself works better with Claude Code than with other harnesses.
5. There's no real lock-in. If tomorrow you decide you don't want to use Claude Code, you can just switch to something else ezpz. So there's no reason to worry that you're digging a hole and locking yourself in. Thus, there's no urgency to switch away.
[0] Yes, open-source harnesses can use your Claude MAX subscription, but does this "benefit" of open-source harnesses really outweigh the costs of #1, #2, and #4 above?
I thought this was pretty much well established that all of the labs have model - harness pairings for exactly this reason
Whale Paper. https://arxiv.org/abs/2609.00196
EMNLP talk from like 2 weeks ago https://aclanthology.org/2026.findings-emnlp.2207/
Correct me if I'm wrong, but using Pi etc you're paying the full API price.
claude setup-token
Eg an agent that only runs off a webhook trigger doesn’t have a use for all the UI stuff Pi does (and you may not want the local state like Pi does by default).
I’m still sort of with you, I’d generally do ACP to an open source agent. You do get much finer grained control if you use one of these agent SDKs (there’s a bajillion of these as well).
ADK has a graph/workflow concept too: https://adk.dev/graphs/
I threw Claude at it to migrate to go sdk finally and had it AB testing it all in a few days. Stuff like that would have taken me forever in the past.
Now to attack some stuff that's in niche as hell jvm languages.
And a lot of the apps are the same thing.
It's going to be a race to the bottom.
So a few people started using grok bot and I'll probably regret that some day, but honestly the deployment model they have here for custom agents is kind of appealing to me, much more than BigLang.
Literally everyday there is a new tool and the tools released last week are deprecated.
I'm not sure if that's what you mean but I know many that are making their own flow like this and think that this brings in a higher level of performance..
Sure, but how are you measuring this?
I feel like people are going down that slippery slope with harnesses and skills and what not. With the right prompt, and with the right model, and with a sprinkle of magic, the solution will emerge. Oh, it didn't? Let's see if there's a new model available, or if someone has come up with a new clever skill or something. Maybe then... Because actually solving annoying problems is not fun, even less so now that the code is a black box only the LLM can understand.
At the same time, the lack of this makes it then very easy for me to tune out harness noise.
Why is a large number of ideas, technologies, frameworks, etc. bad?
I think the difference is that those endless technologies will probably be used by other agents without people's explicit knowledge.
Cursor moving this direction, is a prep work where human no longer command that much , hence the usage will drop. e.g. their core product is vulnerable. Software factories, is the ultimate game over for our industry.
Meanwhile, we know Grok Bot was really Cursor beforehand... it must be wild in there.
Is it to have boundaries of some determinism?
This "runtime" is what you are building with LangChain.. A harness like claude code/codex etc is general purpose and its env is a shell + tools. But with a custom runtime (basically a loop where we ask llm what to do next), we can give it specific tools which we define in code. This can help with things like authorization since, well its custom code you own.. so the runtime gets the tools scoped to the users permissions etc.
The entrypoint still has to come from somewhere, and it's much more convenient to be able to explain the security and legal teams how data is handled, what is logged, how you can have control over a scenario where the agent does something unexpected.
Sure, for a personal project that could be enough, but we all know those companies target enterprise customers, and you would be surprised how little adoption there is when it comes to workflow automation due to the lack of controls.