Sustainability credentials
Hypothetical. Not a client, not a result.
// The problem
Growers are asked by several buyers for proof of sustainable practice, and each buyer receives a different PDF it cannot easily check or trust.
// What we would build
Credentials issued by the certifying body to each farm when an audit passes, anchored on a public chain so any buyer can check that a credential is genuine, current and not revoked, without calling anyone. Only a fingerprint of the credential goes on chain, never farm data. If a single buyer is the only one asking, a signed PDF and a database do the job for less, and we will say so.
// What is in it
- Credential issued by the certifier after an audit, in the W3C Verifiable Credentials format
- A fingerprint anchored on a public chain, with no farm data on chain
- Growers share a credential with a link or a QR code
- Buyers check it is genuine, current and not revoked in one step
- Revocation and expiry handled by the certifier
- Smart contract tested and independently reviewed before launch
// Stack
- Solidity
- Polygon PoS
- W3C Verifiable Credentials
- Next.js
- PostgreSQL
// estimate
- Build
- ≈ US$66,500 to US$102,000, delivered within 20 weeksCAD 94,700 to 144,800
- Hosting
- ≈ US$176 a monthCAD 250 a month
- Support
- ≈ US$1,000 a monthCAD 1,425 a month
Prices in your currency are estimates from today's Bank of Canada rate. All invoicing is in CAD or USD.
Timeline by milestone
- Discovery
- 2.9 to 3.4 weeks
- Specification
- 0.4 weeks
- Design approved
- 2.4 to 4.4 weeks
- Core features
- 1.4 to 2.4 weeks
- Full build
- 0.9 to 1.4 weeks
- Contracts and tests
- 1.4 to 2.4 weeks
- Testing and fixes
- 0.4 weeks
- Testnet deployment
- 2.9 to 3.4 weeks
- Launch
- 0.9 to 1.4 weeks
- Mainnet
- 0.9 to 1.4 weeks
Outside our hands, and added to the calendar
- An outside audit of the contracts, if you want one
- 2 to 4 weeks
How it is paid
- Deposit 20%
- CAD 18,940 to 28,960
- Discovery 4.2%
- CAD 3,977.40 to 6,081.60
- Specification 5.3%
- CAD 5,019.10 to 7,674.40
- Design approved 4.2%
- CAD 3,977.40 to 6,081.60
- Core features 12.6%
- CAD 11,932.20 to 18,244.80
- Full build 8.4%
- CAD 7,954.80 to 12,163.20
- Contracts and tests 16%
- CAD 15,152 to 23,168
- Testing and fixes 4.2%
- CAD 3,977.40 to 6,081.60
- Testnet deployment 5.3%
- CAD 5,019.10 to 7,674.40
- Launch 4.2%
- CAD 3,977.40 to 6,081.60
- Mainnet 5.6%
- CAD 5,303.20 to 8,108.80
- Holdback, 30 days after launch (10%)
- CAD 9,470 to 14,480