Fiber: agreed, and you put the split better than I had. An Action URL is fire-and-forget to a peer the publisher never learns the identity of, while Fiber is a live session between two peers who already share a channel. Cramming that into a stateless URL means smuggling session state through query params, which kills the point. If there’s ever a fiber-action it should be its own thing, not a flag on this one.
Batch actions: you changed my mind. I was conflating two cases. Multiple transactions per link needs orchestration patterns nobody’s built yet, so it’s premature. But multiple operations inside one transaction is just a richer OTX, which CoBuild already handles, so it needs no protocol change. I’ll drop the multi-tx variant and note the single-tx case as already supported.
Swaps: yeah, CKB-for-NFT is the cleanest one. The holder builds an OTX with their NFT as input and a CKB output to themselves; the buyer’s wallet adds the CKB input and the cell that receives the NFT, then signs. No oracle, no external state, the whole deal is legible before anyone signs. That’s the first use case that isn’t just “consumer funds an output” but two parties contributing to one agreed tx, which is really what OTX was built for. If I add a fourth example it’ll be that.
Other things on my list: UDT/xUDT claim links (tip jar with a type script), DAO deposit/withdraw as one-click links, and paywall unlocks gated on the callback.