Tagged protocols
6 pieces
- · 7 min read
Spend Your Effort on the Layer With No Reference Path and No Error Case
In a layered product, risk is not where the engineering is hardest. It is where there is neither a worked reference implementation nor a mechanism that fails loudly. In a camera stack, the firmware layer has a vendor reference path and hardware that inserts framing automatically. The descriptor handshake one layer above has neither, so an error there passes every in-house test and fails only when a third-party host tries to enumerate the device.
- · 7 min read
PLC to Model: Where Industrial AI Actually Breaks
The model is rarely the problem on a factory floor. The problem is the path between the controller and the model: a protocol implemented as the vendor felt like implementing it, a timing budget with the round-trip inside it, a controller that cannot be taken out of service, and a boundary that belongs to neither the automation team nor the data team.
- · 7 min read
Bounded the Wrong Thing: What TCP's 1988 Fix Teaches Your Agent Loop
TCP already had a bound before congestion collapse. The receive window was real, correctly enforced, and nobody had a bug in it. The internet fell over anyway, because that window protected the receiver and the thing failing was the network in between. Jacobson did not delete it. He added a second window measuring the thing that was actually going wrong and took the minimum of the two.
- · 7 min read
Durable Execution Is Not Exactly-Once (and What to Do Instead)
Durable execution replays a workflow and skips the steps that already completed, which narrows the window in which a side effect can run twice. It does not close it, because the gap between performing an effect and recording that you performed it cannot be made atomic across a network boundary. Nothing provides exactly-once. What you get is at-least-once plus a way to make the second one harmless.
- · 12 min read
Why Your AI Agent Reports Success But Nothing Ran: Five Ways a Tool Call Dies
When an agent says it called a tool, the run comes back green, and nothing happened, the model almost never lied. A tool call is just text the model hands off, and it gets dropped somewhere in the plumbing between the model and the tool, in one of five places: streaming, index collision, proxy translation, the wrong finish flag, or no check at the end. A bigger model fixes none of them.
- · 12 min read
Why Your AI Agent Double-Executes: Retry Is a Second Execution, Not a Second Chance
When an agent charges a card twice or sends an email twice, nothing is broken to go find: no error, no red in the logs, the action was correct and simply ran twice. Duplicates enter through four doors, retry, redelivery, redispatch, and double trigger, but a duplicate only hurts you when there is no gate in front of the side effect. The fix is one idempotency key, identical no matter which door it came through.