The Final Stitch: Wiring Remote GPU Proving into Curio's Proofshare Task

The Message

In the middle of a complex integration effort to connect Curio's task orchestrator with a remote GPU proving daemon called cuzk, the assistant issued this deceptively simple message:

Now update computeSnap: [edit] /home/theuser/curio/tasks/proofshare/task_prove.go Edit applied successfully.

On its surface, this is a one-line note followed by a successful file edit — barely a blip in a long conversation. But this message is the culmination of a carefully orchestrated chain of edits, the final piece of a puzzle that had been building across multiple task types and dozens of preceding messages. To understand its significance, one must trace the thread of reasoning that led to this moment.

The Context: A Remote GPU Proving Architecture

The broader effort was the integration of cuzk, a custom GPU proving daemon, into Curio — a Filecoin storage provider orchestrator. Curio manages storage provider operations through a task scheduler that assigns work to local resources (CPU cores, GPUs, RAM). The key insight driving this integration was that Groth16 SNARK proving — the most GPU-intensive phase of Filecoin proof generation — could be offloaded to a remote daemon, freeing local GPUs and enabling centralized, high-utilization GPU clusters.

The architecture split proof generation into two phases: vanilla proof generation, which requires access to sector data and runs on the storage provider's machine, and SNARK computation, the GPU-heavy phase that could be delegated to the cuzk daemon. This split was already implemented in a new file lib/ffi/cuzk_funcs.go, which provided methods like PoRepSnarkCuzk that generate vanilla proofs locally and submit the SNARK work via gRPC.

The assistant had already wired this pattern into two simpler task types: PoRep (seal) and SnapDeals prove. Each followed a consistent template: add a cuzkClient *cuzk.Client field to the task struct, modify the constructor, update Do() to call the cuzk variant, adapt CanAccept() to query the daemon's queue for backpressure, and change TypeDetails() to zero out local GPU/RAM requirements when cuzk is enabled. This last change was critical — it told Curio's scheduler that the task required no local GPU resources, preventing double-counting and allowing the scheduler to dispatch more work than local hardware could support.

The Proofshare Task: A More Complex Target

The proofshare task (PSProve) was the third and most complex target. Unlike PoRep and SnapDeals, which had straightforward Do() methods that directly called SealCalls methods, the proofshare task had a layered architecture. Its Do() method called a package-level function computeProof, which in turn dispatched to either computePoRep or computeSnap depending on the proof type. This meant the cuzk client had to be threaded through three levels of function calls.

The assistant's approach was methodical. Starting at message 3437, it read the proofshare task file, then issued a series of edits:

1. Add the import and client field (msg 3438-3439): Import the cuzk package and add cuzkClient *cuzk.Client to the PSProveTask struct.
2. Update Do() (msg 3440): Pass the client through to computeProof.
3. Update computeProof signature (msg 3441): Add the *cuzk.Client parameter and update its callers.
4. Update computePoRep signature (msg 3442): Add the *cuzk.Client parameter.
5. Update computeSnap signature (msg 3443): Attempt to add the parameter, but the edit was incomplete — the LSP reported that computeSnap still had the old signature.
6. Final fix (msg 3444, the subject message): Complete the computeSnap signature update.

The Thinking Process: Error-Driven Iteration

What makes this message interesting is what it reveals about the assistant's working method. The assistant was operating in a tight feedback loop with the LSP (Language Server Protocol) diagnostics. After each edit, it would check for errors and fix them. This is visible in the chain of LSP errors:

• After msg 3441: computePoRep still had old signature (too few arguments)
• After msg 3442: computeSnap still had old signature
• After msg 3443: computeSnap still had old signature (the edit added fmt to imports but apparently didn't fully update the function)
• After msg 3444: Success — no LSP errors reported The assistant was working through a dependency graph of function signatures. computeProof calls both computePoRep and computeSnap, so all three needed their signatures updated. The assistant updated them in order: computeProof first, then computePoRep, then computeSnap. But the computeSnap update in msg 3443 apparently only added the fmt import without fully updating the function signature — perhaps the edit was narrowly scoped. Message 3444 completes the job. This reveals an important assumption: the assistant assumed that updating the function signature in one edit would be sufficient, but the LSP revealed otherwise. The error-driven iteration shows the assistant treating the LSP as a real-time validation layer, catching mistakes that would otherwise surface only at compile time.

Input Knowledge Required

To understand this message, one needs to know:

1. The cuzk architecture: That SNARK proving is being split from vanilla proof generation, with the former offloaded to a remote daemon via gRPC.
2. The Curio task model: That tasks have Do() (execute work), CanAccept() (check if task can be accepted given resource constraints), and TypeDetails() (report resource requirements) methods.
3. The proofshare task's internal structure: That it delegates to computeProof, which dispatches to computePoRep or computeSnap — requiring the client to be threaded through all three.
4. The Go type system: That adding a parameter to a function requires updating both the function definition and all call sites, and that the LSP catches mismatches at the editor level.
5. The preceding work: That PoRep and SnapDeals tasks had already been wired, establishing the pattern being applied here.

Output Knowledge Created

This message produced a successful edit that completed the computeSnap function signature update. The output is:

• A corrected function signature: computeSnap now accepts *cuzk.Client as a parameter, matching the call sites in computeProof.
• A fully wired proofshare task: With this edit, all three proof-related task types (PoRep, SnapDeals, PSProve) have been integrated with the cuzk daemon.
• A validated pattern: The consistent approach of adding a client field, updating Do(), CanAccept(), and TypeDetails() has been proven across three distinct task implementations.

Significance: The Last Piece

This message represents the final stitch in a larger tapestry. The proofshare task was the most complex integration target because of its layered function calls. By completing the computeSnap signature update, the assistant ensured that the cuzk client would flow correctly from the task's Do() method, through computeProof, and into either computePoRep or computeSnap — whichever proof type was needed.

The broader significance is architectural. The integration transforms Curio from a purely local task executor into a hybrid orchestrator that can dispatch GPU work to remote daemons. This enables several operational patterns: consolidating expensive GPUs into fewer machines, running proving daemons on optimized hardware (e.g., cloud instances with A100s), and decoupling storage capacity from proving capacity. The CanAccept() backpressure mechanism ensures that Curio's scheduler doesn't overcommit the daemon's queue, while the zeroed TypeDetails() costs prevent double-accounting of GPU resources.

Conclusion

Message 3444 is a study in how complex integrations are built: not through grand gestures, but through a sequence of small, error-corrected steps. Each edit built on the previous one, each LSP error guided the next fix. The message itself is barely a sentence, but it represents the successful resolution of a multi-step dependency chain — the moment when the last function signature clicked into place and the proofshare task joined PoRep and SnapDeals in the cuzk-enabled future. In the architecture of the integration, this was the final connection, the last wire soldered, completing the circuit between Curio's task scheduler and the remote GPU proving daemon.