EAS · IPFS · Base Mainnet
Verify any
data point independently
Every response from the AssayChain API includes an EAS attestation UID and an IPFS CID. No trust required — verify the source data directly on base.easscan.org and IPFS.
How provenance works
From field to API in four steps
Field collection
Each run is recorded in the field using MineFlowTrack — AssayChain’s dedicated field data capture tool (a Quetzal Collective progressive web app). Data is captured against the locked v1 schema: run ID, date, site coordinates (rounded to ±0.1°), feed type, tray geometry, ultrasound parameters, flow rate, feed mass, and recovery rate. Stored in Firebase Firestore.
IPFS storage
The completed run JSON is stored on IPFS — a distributed network where each file gets a unique address derived from its content (called a CID). If the data ever changes, the CID changes too, making tampering immediately detectable. The file is content-addressed, not URL-addressed: no central server can alter what the address points to.
EAS attestation on Base
An EAS attestation is created on Base mainnet, encoding the run data fields and IPFS CID against the registered schema. The resulting UID is a permanent, on-chain record. The attesting wallet is the single source of truth for the operator's identity.
API delivery
When you call /benchmark/research/mineral-processing/{study} via the x402-gated API, each run in the response includes its attestation_uid and run_cid. You can verify either independently, any time, without AssayChain's involvement.
EAS Schemas on Base mainnet
Three registered schemas
All three schemas are registered and UID-committed on Base mainnet in the EAS Schema Registry.
Benchmark schema
Used for USGS commodity summaries (gold, silver, copper).
Schema name: mineral-intel-benchmark-v1
0xde9e029944dd16f3dad09458ec50b1823e4fbeaa35e6779509aeb84059bb8531
District report schema Live on Base
Used for curated historical mining district reports (/historical). Revocable — a new attestation is issued when district data is enriched.
Schema name: mineral-intel-district-v1
0x4a7843b41982a42f574c2afab7bab592c0bcce1930ce3d3afae300a1084bf620
Committed fields: string district_slug, string source, string source_url, string result_cid, string attestation_date
Run log schema Live on Base
Used for each field season run log attestation.
Schema name: mineral-intel-processing-run-v1
0x043a1d38402b3026ab8512a38d72fc0b88afbf3b6a95468e889212a582d2943a
Registered on Base mainnet 2026-05-19. Zero resolver, revocable: false. Each field run attestation encodes the 10-field canonical set on-chain; full measurements live in the IPFS-pinned JSON at run_cid.
Committed fields: string run_id, string date_utc, string site_district, string feed_type, string tray_geometry, uint32 ultrasound_frequency_khz, uint32 ultrasound_power_w, uint32 recovery_pct_estimated, string run_cid, string notes
Independent verification
Three ways to verify
Verify on EASScan
Take the eas_uid from any run log response. Go to base.easscan.org, search the UID. The full attestation — schema, data fields, attester wallet, timestamp — is on-chain.
Verify on IPFS
Take the ipfs_cid from any response. Fetch it via any IPFS gateway: https://ipfs.io/ipfs/<cid>. The returned JSON should match the data in the API response exactly — content-addressed, immutable.
Query EAS directly
Use the EAS SDK or GraphQL API to query all attestations against the run log schema UID on Base mainnet. You can reconstruct the full run log history without using the AssayChain API at all.
Infrastructure
How the stack is composed
| Layer | Technology | Role |
|---|---|---|
| On-chain attestations | Ethereum Attestation Service (EAS) | Permanent, typed records on Base mainnet. Two locked v1 schemas — one for commodity benchmarks, one for field run logs. |
| Decentralized storage | IPFS | Full run JSON stored before attestation. Each file is content-addressed — the CID is committed to the EAS record, making tampering detectable. |
| Payment settlement | x402 + CDP Facilitator | $0.10 USDC per call settled on Base mainnet via EIP-3009 authorization. No accounts, no API keys. |
| API | Cloud-hosted REST API | Single Express endpoint serving benchmark and run log data. All data endpoints gated by x402 middleware. |
| Web presence | CDN hosting | Dual-domain global edge delivery for resilience and availability. Agents that cache a base URL keep working through any single-domain incident — no retry logic, no failover code required. Fewer redundant HTTP retries means lower AI inference energy per successful call. |
| Field data capture | MineFlowTrack (PWA) | MineFlowTrack — AssayChain’s offline-capable field data tool. Exports v1 bundles for attestation. |