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Notes from the layer.

Engineering, product, and compliance writing from the people building OpenSettle.

Product·May 11, 2026

Your payment processor is holding your money right now. We built one that can't.

Card processors hold your revenue for days by design. PayPal can freeze a balance for up to 180. Stripe added USDC settlement and kept the holding model. There's a structural alternative — wallet-to-wallet, processor-never-touches-it — and it changes the math on what your billing layer can promise.

OpenSettle Team7 min read
Product·May 11, 2026

How protocols are billing in 2026 (and why it's not what you think)

The story you hear is "protocols capture value via a token." The story that's actually playing out is "protocols bill in USDC, route to a multisig, and skip the token entirely." The shift is real and almost certainly under-covered because it's not photogenic.

OpenSettle Team7 min read
Engineering·May 11, 2026

The one line of code that prevents fake payment notifications (and the seven that make it bulletproof)

An attacker who knows your webhook URL can post fake payment.confirmed events and convince your application to provision unpaid access. The defense is constant-time HMAC verification — one line of crypto, easy to get subtly wrong. Here's the canonical implementation and the four failure modes we've seen in incident reviews.

OpenSettle Team6 min read
Engineering·May 11, 2026

Accepting USDT on Polygon: the cheapest stablecoin rail for emerging-market SaaS

USDT on Polygon is the rail your customers in Argentina, Nigeria, Turkey, and the Philippines are already using. Gas typically sub-cent, settlement in seconds, zero card-network FX margin. Here's the integration guide and the unit-economics math that makes this the obvious choice for emerging-market B2B SaaS.

OpenSettle Team7 min read
Product·May 10, 2026

Stripe vs OpenSettle for stablecoin billing on a crypto SaaS

Stripe added USDC settlement. We never left. A side-by-side for engineers evaluating both — honest about what each does well, what each doesn't, and where the right answer is to run both.

OpenSettle Team9 min read
Compliance·May 9, 2026

The claims we removed from our marketing (and why)

Six weeks ago our marketing overstated chain support and quoted a settlement-time number that wasn't measured. Both were wrong in different ways. Here's the audit, the corrections, and the guard script that prevents a recurrence.

OpenSettle Team6 min read
Engineering·May 4, 2026

What "confirmed" actually means for stablecoin payments: a chain finality field guide

Block confirmation, probabilistic finality, and re-org probability across the four EVM networks where OpenSettle settles. Pick the right wait for your risk tolerance — and stop treating "one confirmation" as a synonym for "safe".

OpenSettle Team8 min read
Engineering·Apr 30, 2026

Reorg-safe payment confirmation: the failure mode nobody puts in their docs

Your customer pays, your dashboard says confirmed, then the chain re-organizes and the deposit transaction is no longer on the canonical chain. Here's how OpenSettle detects that, flips the state machine, and notifies the merchant — and how to design billing systems that don't blink when it happens.

OpenSettle Team7 min read
Product·Apr 27, 2026

Why we bill off-chain instead of running an on-chain splitter

Platform-fee architecture is a load-bearing decision. We picked the boring answer for a reason — and a smart-contract splitter is still on the roadmap as an opt-in.

OpenSettle Team6 min read
Engineering·Apr 22, 2026

Verifying wallet signatures across EVM, Solana, and Tron

Three signature schemes, three wire formats, one product surface. A walkthrough of how we cryptographically verify a merchant owns the wallet they say they own.

OpenSettle Team8 min read
Engineering·Apr 18, 2026

Worker heartbeats and a production preflight that fails fast

When a worker silently stops ticking, payments stop confirming. Here's how we use heartbeat rows in Postgres and a single preflight endpoint to catch that before customers do.

OpenSettle Team7 min read