Delta Registry is a pay-per-event (PPE) data infrastructure operation: 28 hosted Apify Actors that turn government registries, regulatory feeds, and compliance-adjacent public data sources into structured, delta-aware event streams. Every actor in the fleet shares the same design discipline — a dual-fingerprint (or hash-based) delta engine that tracks state across runs, a documented Pay-Per-Event pricing model billed only for genuinely new or changed records, zero-infrastructure hosting on Apify's platform, and honest, disclosed limitations rather than smoothed-over marketing copy. The fleet spans six practice areas: government procurement and grants, regulatory enforcement and litigation, patent and trademark monitoring, sanctions and compliance screening, AI/content infrastructure, and financial markets/sovereign debt.

This profile is the entry point to the whole fleet. Every listing below links to either a real, open-source integration repository (README plus working Node.js and Python apify-client examples under examples/, with an architecture diagram on most) or, for actors not yet mirrored to their own repository, directly to the live Apify Store listing.

Five new Actors shipped this cycle, each targeting a compliance-data niche with no existing structured feed:

All five are now live on the Apify Store. KIPRIS Patent & Trademark Status-Change Monitor's earlier platform-side publish error cleared and it went public on 2026-09-17.

Four new Actors shipped this cycle, extending the fleet into public procurement (EU-wide), UK statutory compliance, sovereign-debt markets, and Gulf corporate registries:

All four are live on the Apify Store as of 2026-09-17. Honest status note: ADGM and DIFC (two of the UAE actor's three data sources) are currently affected by live, ongoing outages on those registries' own servers (a NullPointerException on ADGM's side, an HTTP 500 on DIFC's) — confirmed independently, unrelated to this actor's code, and being monitored via a standalone health probe shipped in that actor's own repository.

• Pay only for signal. Every Actor bills on a Pay-Per-Event model — a baseline/no-diff record is always free; you're charged only when something genuinely new or changed is delivered.
• Delta-aware by default. Cross-run state (SHA-256 or content-hash fingerprints, persisted in a named Key-Value Store) means a scheduled run reports only what moved since the last check, never a full re-dump.
• Zero infrastructure. No server, cron host, proxy pool, or session-cookie logic to maintain — Apify's platform runs the schedule, the retries, and the persisted state.
• Disclosed limitations, not hidden ones. Every Actor's README states what it cannot do (fuzzy name matching, source refresh cadence, PDF text-layer failures) as plainly as what it can.
• BYOK where the underlying data source is itself a paid product (e.g. KIPRIS Plus) — so operator margin never rides on marking up someone else's license.

• Run any Actor today — browse the full catalog at apify.com/stefano_seggio; every listing is pay-per-event with no subscription.
• Enterprise licensing, custom monitors, or a new jurisdiction added to an existing fleet — reach out directly on LinkedIn.
• Integrating via API — every repository above ships real Node.js and Python apify-client examples under examples/; no SDK to install beyond the official Apify client.