Four layers, each doing one job.
Meridian is the engineering behind KTE, the Kenya Traceability Ecosystem. It exists because the evidence a European buyer now has to produce about a consignment — which plot, whose land, which inspection, what cold chain — is evidence that was never collected in one place, and the parts that were collected were on paper, in the hands of whoever benefits from them being favourable.
Identity
Who is this, and who says so?
Every participant — a farmer, a cooperative, a packhouse, an inspecting authority — holds a Decentralised Identifier, a W3C standard for an identity that is not issued by, and cannot be revoked by, whoever happens to run the platform.
Certifications and registrations are issued against those identifiers as Verifiable Credentials, signed by the body that granted them. When KEPHIS passes an inspection, the pass is signed by KEPHIS. Meridian carries it; Meridian does not vouch for it, and could not forge it.
Events
What happened, where, and when?
Each handoff is recorded as a GS1 EPCIS 2.0 event — the international standard for supply chain events. Harvest, collection, aggregation, packing, inspection, loading, departure: each one is written by the party performing it, at the time they perform it.
Using the standard vocabulary rather than a Meridian-specific one is the difference between a record a European buyer's own systems can read and one that needs an integration project first.
Ledger
Can anyone quietly change it later?
Activity is recorded on Hyperledger Fabric, a permissioned ledger shared between participants. Permissioned matters here: commercial volumes and prices are not public information, and a fully public chain would make them so.
So that the permissioned ledger is not simply trusted on its own word, batches of issued credentials are hashed into a Merkle tree and the root is written to a public chain. Anyone can later prove a specific credential was in a specific batch, and has not been altered since, without asking Meridian anything at all.
Access
Who can actually use it?
A traceability system that only works for the well-equipped end of the chain produces a record that starts at the packhouse — which is to say, a record that cannot answer the question buyers are now legally required to ask about the farm.
So the entry points run from a USSD menu on any GSM handset, through offline-capable Android apps for field agents and inspectors working outside network coverage, to browser portals and an API for exporters and importers.
The chain, stage by stage
- Stage 01
Farm
The plot is registered with its geolocation and the farmer receives a registration credential. Harvest is recorded against that plot.
- Stage 02
Cooperative
Collection and aggregation are recorded by the cooperative, which may sign on a member's behalf under an explicit, revocable delegation.
- Stage 03
Packhouse
Grading, packing and palletising. Cartons and pallets get GS1 identifiers, and the cold chain starts being recorded.
- Stage 04
Inspection
KEPHIS inspects the consignment and signs the result as a credential bound to it — the pass travels with the goods.
- Stage 05
Freight
Export declaration, airline acceptance and departure are captured as events, not as a separate paper file.
- Stage 06
Shelf
The importer verifies on receipt. The consumer scans the pack and sees the same record, from the same source.
What that buys you
- GS1 EPCIS 2.0
- The event vocabulary is the GS1 standard, not a Meridian invention. An external system can read the record without an adapter written for us.
- W3C DIDs and VCs
- Identity and certification use open W3C specifications, so a credential Meridian issues can be checked by software Meridian did not write.
- Public anchoring
- Credential batches are Merkle-rooted and the root is written to a public chain. Inclusion can be proven independently, without asking Meridian anything.
- Authority-signed, not self-declared
- A certification credential is signed by the body that granted it. Meridian carries it; Meridian does not vouch for it.