certi.art — Filecoin-backed provenance infrastructure for small and medium European art galleries

## Project name

certi.art

## Team

**Solo founder:** Mateusz Zabielski

**Legal entity:** THE BEST ZABIELSKI MATEUSZ ZABIELSKI — jednoosobowa działalność gospodarcza (Poland), NIP 5223029109, continuously operating since 2015-06-01. Established Polish tax discipline, no startup-shell setup risk. The existing core business (regeneration of automotive parts) is unrelated to certi.art; certi.art is a new digital-services brand within the same legal vehicle.

**Working language:** Polish primary, technical work in English.

**Email:** mateuszxzabielski@gmail.com

## Category

**Integrations** — adding integration / support for Filecoin into a new builder community (small and medium European art galleries) that would not, on their own, set up Filecoin storage deals or understand storage-network tooling.

## What is the project?

certi.art is an open-source provenance infrastructure for art galleries: certificates of authenticity for physical artworks, soulbound profile tokens for artists and galleries, and an optional Mint Digital module for standalone digital editions — all anchored in content-addressed metadata intended for long-term Filecoin persistence. The smart-contract stack is already live on Ethereum Sepolia testnet (12 on-chain addresses, all source-verified on Etherscan); this grant funds the off-chain infrastructure that turns this into something a non-crypto gallery can actually use, with Filecoin persistence integrated transparently into the gallery-facing workflow.

The Ethereum contracts are not being moved to Filecoin: Ethereum serves as the trust and issuance anchor (immutable record of which artist / gallery issued what, when), Filecoin as the long-term persistence layer for the provenance metadata and associated media.

## Why we are writing to Filecoin DevGrants specifically

Filecoin Foundation has built the strongest cultural-preservation track record in the decentralized-storage space, with public partnerships supporting the Smithsonian Institution, the Internet Archive, the Flickr Foundation, MIT Open Learning and Starling Lab, and over 500,000 culturally significant digital artifacts safeguarded on the network. certi.art extends this principle one layer further: to the long tail of small and medium European art galleries that currently rely on fragmented paper certificates, emails and spreadsheets — and that will not, on their own, set up Filecoin storage deals.

This is a direct Integrations-category fit: the grant funds the work of making Filecoin persistence available to a builder community (European galleries) that has no current path into the Filecoin ecosystem.

## What problem does it solve / why is it valuable

Three direct alignments with Filecoin DevGrants priorities:

1. **Cultural preservation at the gallery level.** Filecoin's existing cultural-preservation partners are large institutions. certi.art extends the same principle one layer down — to small and medium European art galleries. Every certificate issued through certi.art is intended as a long-lived provenance record anchored both in IPFS (for content-addressing) and Filecoin storage deals (for verifiable long-term persistence beyond pinning services). The grant explicitly funds the Filecoin-backed persistence integration so that this anchoring is transparent to the gallery user.

2. **Developer tooling and ecosystem applications.** Grant deliverables include an open-source frontend reference implementation (Next.js + Privy embedded wallet + wagmi) licensed under MIT or Apache 2.0, published as a public repository. Galleries and developers wishing to build on the same Filecoin-anchored content-addressed provenance model gain a working starting point — including the Filecoin integration patterns we will document.

3. **Public-good infrastructure with regulatory readiness.** certi.art ships with explicit Polish/EU regulatory framing: non-speculative authentication scope, a legally cautious erasure pattern (subject to ongoing legal review under dispatched lawyer memo v4.0 PL), KIS individual tax interpretation request submitted to Polish tax authority, lawyer memo dispatched to qualified IT/IP firms. For Filecoin's mission of decentralized storage for humanity's data, regulatory readiness at the European level is a force multiplier — it widens the addressable institutional and gallery audience that can adopt Filecoin-anchored provenance without legal anxiety.

## Current state / what's already built

- **Four logical smart contracts live on Ethereum Sepolia testnet since 2026-05-20**, each behind an upgradeable proxy. 12 on-chain addresses total (4 implementations + 4 proxies + 4 ProxyAdmins), all source-verified on Etherscan. Soulbound profile layer (ERC-5192), immutable Certificate of Authenticity (ERC-721), Authorization Registry, optional Mint Digital module.

- BridgeSBT proxy: https://sepolia.etherscan.io/address/0x53f912BDB904864a6efe9A8CaD9d367000c35135
- BridgeRegistry proxy: https://sepolia.etherscan.io/address/0x15De66D4E5407606b484bA9F1b7C3d2f4CcD540d
- BridgeCertificate proxy: https://sepolia.etherscan.io/address/0xC4574Fbe144521a5acE5cA109c23468bBCf831e3
- BridgeDigital proxy: https://sepolia.etherscan.io/address/0xc18BC195A83b9CD9d3F21633B46736d50678b651

- **500+ Foundry tests on main**, 29 property-based invariants, all four contracts at 91%+ branch coverage and 100% function coverage. Frozen audit-baseline-v3 git tag (commit 5570c23) prepared as engagement target for external audit when funding allows.

- **Content-addressed metadata pipeline structured for Filecoin-backed persistence.** Every certificate's metadata, artwork media and optional artist signature image is content-addressed on IPFS by design; the on-chain layer holds only pointers, hashes, status enums, and role-gated events. The architecture uses a legally cautious EU/Polish pattern (still subject to ongoing legal review under lawyer memo v4.0 PL): avoid putting unnecessary personal data into immutable content-addressed metadata; remove platform-controlled pins; terminate or avoid renewing platform-controlled storage deals where applicable; redact mutable off-chain presentation layers when required. The grant-funded work integrates Filecoin-backed persistence through Lighthouse.storage or equivalent tooling, and documents the integration pattern so gallery operators do not need to understand storage-deal mechanics directly.

- **Industry-standard Solidity static-analysis suite fully triaged**, no untriaged findings. Storage-layout regression check active in CI. Real proxy upgrade test (7 tests exercising upgradeAndCall end-to-end). Gas baseline committed.

- **Operational discipline evidence:** during Sepolia broadcast preparation on 2026-05-20, the deploy script's defensive chainid guard caught a misconfigured RPC endpoint before any gas was spent. Documented internally as a real-world defense-in-depth case study.

- **ORD-IN individual tax interpretation request submitted** to Krajowa Informacja Skarbowa (KIS) via ePUAP, covering VAT classification for SaaS subscriptions, per-certificate fees, free-tier sponsored gas, and EIP-2981 royalty tax treatment. Lawyer memo v4.0 PL dispatched to qualified Polish IT/IP firms covering INVITE_ARTIST email-invitation flow, RODO erasure model, Terms of Service for embedded-wallet onboarding.

## Roadmap and milestones (6 months from grant start)

1. **Month 1 — Legal review and compliance documentation (first disbursement priority).** Polish IT/IP law firm engagement (follow-up on dispatched lawyer memo v4.0 PL). Drafting of Terms of Service, Privacy Policy, anchor pilot agreement. No paid customer transaction happens before this completes.

2. **Months 2–4 — Open-source frontend MVP.** Next.js + Privy embedded wallet + wagmi. Panels for: artist registration / SBT issuance / Certificate of Authenticity issuance / Mint Digital issuance / gallery dashboard / admin panel. Repository published under MIT or Apache 2.0 licence.

3. **Month 3 (parallel with frontend) — Filecoin-backed persistence integration.** Lighthouse.storage SDK integration or equivalent FVM-aware tooling. Smart contracts remain unchanged; the integration is entirely in the off-chain pipeline. Documented integration pattern published.

4. **Month 5 — Anchor pilot execution end-to-end on Sepolia testnet** with Galeria Moneli (Warsaw, Poland). At least one Artist SBT, one Certificate of Authenticity and one Mint Digital edition issued, with full Filecoin persistence in the pipeline. Public verification pages functional.

5. **Month 6 — Documentation, outreach, and post-grant package.** Filecoin integration patterns documentation alongside the open-source repository. Cold-validation outreach: 30–50 PL/EU galleries contacted, 5–10 guided Sepolia demos. Mainnet decision package documented (deployment gated by separate audit funding and lawyer green-light; itself a post-grant action).

## Budget request

**EUR 10,000–20,000 over approximately 6 months (USD equivalent acceptable).**

| Line item | EUR | Notes |
|---|---|---|
| Legal review + compliance documentation | 3,000–5,000 | First disbursement priority. Polish IT/IP firm follow-up + ToS / Privacy Policy / pilot agreement drafting. |
| Open-source frontend MVP + Filecoin persistence integration | 3,000–5,000 | ~40 working days of focused solo build using AI-assisted tooling. Repository published MIT/Apache 2.0. |
| Development assistant tooling (6 mo) | 2,000 | Implementation tooling for the solo build. |
| IPFS / Filecoin / infrastructure (6 mo) | 1,000 | Pinata, Lighthouse.storage / Filecoin deals, Alchemy RPC, Supabase EU, Privy, domain. |
| Outreach to galleries + intro materials | 500–1,000 | 30–50 gallery target list + email tool + 1-page Polish intro document. |
| Contingency / unscoped | 500–2,000 | Reserved for items discovered during the build. |
| **Total realistic range** | **10,000–16,000** | |

**External smart-contract audit is intentionally out of scope of this grant** — see attached master brief §5. Mainnet activation is gated by separate audit funding and lawyer green-light, both post-grant.

## Repository

GitHub: `github.com/trenie-trenie/bridge-contracts` (currently private — read access on request to reviewers).

## Attached materials

The full master grants brief is attached below in both PDF and DOCX formats:
- `certiart_grants_brief_EXTERNAL_v5.6.pdf` — full project state, success criteria, founder profile, anchor pilot disclosure (renders in-browser on GitHub)
- `certiart_grants_brief_EXTERNAL_v5.6.docx` — editable source format

[certiart_grants_brief_EXTERNAL_v5.6.pdf](https://github.com/user-attachments/files/28098191/certiart_grants_brief_EXTERNAL_v5.6.pdf)

[certiart_grants_brief_EXTERNAL_v5.6.docx](https://github.com/user-attachments/files/28098193/certiart_grants_brief_EXTERNAL_v5.6.docx)

Additional materials available on request:

- Internal state briefing (2026-05-20) — repository state, test counts, coverage tables, defense-in-depth case study
- Lawyer memo v4.0 PL — Polish, 4 priority questions to qualified IT/IP firms
- KIS ORD-IN individual tax interpretation request copy
- Architecture Decision Record for the BridgeDigital module (Mint Digital, separate audit scope)
- Read access to private repository github.com/trenie-trenie/bridge-contracts

## Contact

Mateusz Zabielski
Founder, certi.art
mateuszxzabielski@gmail.com