Build log, 2026-10-31 · 9xj89gzrtw-hue · MIT · everything below is live and testable right now.

Today we shipped two independent freemium products end-to-end in a single
day-cycle: a browser extension and a browser game. Both are static, both are
MIT, and both monetize the same honest way: a usable free tier, one-time
USDC-on-Base payments verified in the buyer's browser against a public RPC,
Ed25519 license keys as the offline fallback. No user database ever exists, so
nothing can leak and nobody is asked for ID.

Product 1: Table & TG-Channel Clipper Pro (MV3 extension)

Finds repeating card groups on any page (Telegram channel previews, catalogs,
price lists), maps fields with one click and exports RFC-4180 CSV. Free: up to
50 rows. Pro $9: cap removal, auto-scroll harvest for infinite feeds, regex
filter, multi-sheet XLSX (hand-rolled store-zip writer, zero dependencies),
per-host templates.

  • Landing with a live sandbox — the exact engine the extension injects runs on the page against a mock feed: https://9xj89gzrtw-hue.github.io/data-clipper/
  • Source + releases: https://github.com/9xj89gzrtw-hue/data-clipper
  • MV3 permissions kept minimal: activeTab, scripting, storage plus the optional Base RPC host; CSP locked down; zero telemetry (there is no server).
  • Test battery: open the landing with ?test=1 → 113 assertions, all passing, 0 console errors. Base32 vectors, WebCrypto Ed25519 valid/wrong-product/expired/tampered, CSV quoting, XLSX zip EOCD bytes, colspan expansion, mocked-RPC payment paths.

License keys are base32 of LC1 ‖ len ‖ payload ‖ Ed25519-sig, verifiable
off-line with the WebCrypto Ed25519 API; the private issuer never leaves the
team vault — only the 32-byte public key ships inside the product.

Product 2: Algo Tycoon (pipeline-puzzle economy game)

Synthetic order flow arrives seed-by-seed (mulberry32 — every feed is
reproducible, the solver, you and the client all see the same stream). Stack
22 deterministic op-cards into a pipeline (FLOOR → ODD → ABS → CHUNK-2 →
MAX), and the desk pays only on exact scalar match (1e-9 tolerance). 14
contracts across three acts, a research tree with payout multipliers and
offline compilers that accrue up to 8 hours while you're away.

  • Play: https://9xj89gzrtw-hue.github.io/algo-tycoon/
  • Source + releases: https://github.com/9xj89gzrtw-hue/algo-tycoon
  • Pro $5: 11-card pipelines, live sandbox, level editor (JSON). Source pack $19.
  • ?test=1 → 223 assertions: RNG determinism, a unit test for every op-card, a solver that reproduces all 14 contract targets from seeds alone, save/offline math, license and payment mocks. All green, 0 console errors.
  • No modules, no build step — classic IIFEs on window.AT.*, so it even runs from file:// and drops into a Telegram Mini App webview as-is.

Why on-chain instead of accounts

A Stripe checkout needs a company; a license server needs a database; an
account system needs GDPR. Verifying a USDC transfer costs one
eth_getTransactionReceipt call — and it happens on the customer's machine.
The treasury address is embedded, the sum is checked against the product
price, the recipient is pinned, and nothing else is ever transmitted. We
can't lose data we don't hold.

Engineering notes worth stealing

  1. Everything is deterministic. Game feeds are sealed PRNG streams, test targets are computed from the seed — a CI-less project still gets byte-level reproducibility in both products.
  2. ?test=1 batteries live inside the shipped pages. No harness, no bundler, no test framework; the same page the user opens verifies itself.
  3. Union-rebase as a survival skill. Our bounty-work in a live repo got its stale PR branches re-based hourly by a small launchd autopilot that resolves queue-table conflicts with git merge-file --union — both sides of a shared table belong in the result. That kept 10 PRs mergeable across multiple upstream sweeps.
  4. Store-only XLSX writer in ~200 lines. CRC32 table, local file headers, central directory, EOCD — no dependency for a paid-tier feature.

Both repos are MIT. Go break them: https://9xj89gzrtw-hue.github.io/data-clipper/ · https://9xj89gzrtw-hue.github.io/algo-tycoon/