PVQ (formerly XCQ) – Completion Report & Retroactive Funding Request

1d 7hrs ago
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Executed

PVQ (formerly XCQ) – Completion Report & Retroactive Funding Request

Track: Polkadot Fellowship Treasury
Date: 12 Aug 2025
Proponent: 14DsLzVyTUTDMm2eP3czwPbH53KgqnQRp3CJJZS9GR7yxGDP
Beneficiary: 12zgSMDwF5xpzcksvEdDzcSFouFNroXGRffgnhogSk1kR7iS
Amount requested: 102,054 DOT (≈ $399,680 USD)

TL;DR

PVQ (PolkaVM Query), previously named XCQ, is now implemented with end-to-end demo. It standardizes cross-consensus (cross-chain) queries with a protocol, reference implementation, runtime components, SDK, docs, and a live demo. This request covers the remaining payment for the previously granted proposal (https://polkadot.subsquare.io/treasury/proposals/831). An upfront tranche of 49,075.43 DOT (USD 334,400) was received; this proposal requests a one-time payout of 102,054 DOT to settle the remainder.

What is PVQ

PVQ is a framework for querying data across chains. It is designed to integrate cleanly with PolkaVM and to operate alongside XCM or via runtime APIs and SDKs for off-chain clients. Goals:

  • Minimal, extension-based core for flexibility
  • Consistent query model across heterogeneous chains
  • Clean developer experience via SDKs and examples

Links (deliverables)

Scope delivered

All milestones from the original XCQ proposal are complete:

  • Protocol and core design
  • Reference implementation in Rust (PolkaVM-based)
  • PVQ pallet and runtime library
  • TypeScript/JS SDK
  • End-to-end demo and developer documentation
  • Initial extension set covering common cross-chain data needs

Impact

PVQ removes fragmentation for builders who need accurate, verifiable cross-chain data:

  • On-chain use: staking pools that query Relay Chain rewards; automated coretime buyers; cross-chain treasury ops that need prices, fees, and slippage.
  • Off-chain use: wallet and bridge UX with correct fee computation; universal dApps that discover features and build extrinsics reliably.

Work summary and team

  • Effort: 68 weeks at 1.2 FTE (core delivery) + 4 weeks frontend engineering
  • Team: 1 full-time blockchain engineer; 1 CTO at 10%; 1 PM at 10%; 1 frontend engineer for 4 weeks
  • Reference rate used for planning: USD 220/hour

Funding request

Requested payout: 102,054 DOT to the beneficiary above.
Rationale:

  • Core: 68 weeks * 1.2 FTE * 40 h/week * 220 USD/h = 718,080 USD
  • JS SDK & Frontend Demo: 4 weeks * 40 h/week * 100 USD/h = 16,000 USD
  • Subtotal: 734,080 USD
  • Less upfront received: 734,080 - 334,400 = 399,680 USD
  • With DOT EMA7 Price: 3.916348 = 102,054 DOT

Next steps: PVQ in polkadot-sdk and system chains

We intend to integrate PVQ into polkadot-sdk and integrate it into system parachains and relaychains. Early discussion: https://github.com/paritytech/polkadot-sdk/issues/8251. We will submit a separate proposal for this integration.

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Request
102.05KDOT
Status
Decision7d
Confirmation
30mins
Attempts
1
Tally
100%Aye
56.1%Threshold
0%Nay
Aye8
Nay0
  • 0.0%
  • 0.0%

    Threshold

  • 0.0%
Bare Aye3
Max Voters24
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Comments

In the fellowship meeting in Berlin, we had some conversations about the overlap between PVQ and runtime view functions, among a few concerns about breakage and if/where this approach is really useful. I don't have all the details in mind now, but my impression after that conversation was that think further before moving forward. Can you please provide a summary of what points you learned from that conversation, and how you are addressing them? I think we can find them in the notes taken by Anaelle.

Although, I realize this proposal is requesting payment for what was previously agreed upon, so my comment is only relevant for any upcoming work.

Thanks!

Edited

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Thanks for the reply @Bryan Chen . I've already voted aye as this is the remainder of the payment for work that is already done and is approved.

For any future work, in-line with the treasury, let's submit a proposal before the work is done and get it approved, instead of retroactive. In there, we can also further discuss any details.

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Resubmit of https://collectives.subsquare.io/fellowship/referenda/391 which failed to execute due to wrong track (Fellows instead Architects)
Updated DOT amount based on new Subscan DOT EMA7 Price ( USD ): 3.840751

Edited

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