← halfin journalApr 28, 2026 · 6 min read
Changelog

Changelog: Q2 2026 SPL settlements, batch v2, EU MiCA notes

Solana SPL is now a first-class settlement rail, batch payouts get idempotent re-submission, and MiCA Phase 2 affects our roadmap.

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halfin Q2 2026 changelog cover
changelog · cover
photo · Logan Voss on Unsplash

What shipped, what changed, and what's queued. Every change is versioned, every breaking change has at least 90 days of notice, and our public OpenAPI tracks the live contract.

Shipped this quarter

Solana SPL as a first-class settlement rail

Both invoice acceptance and payouts now route through SPL with the same idempotency and webhook guarantees as our ERC-20 and TRC-20 rails. Sub-second confirmations, near-zero fees, and a growing list of supported tokens: USDC, EURC, plus a curated set of regional stables.

settlement latency · spl
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SPL settlement latency, p50/p95/p99

Batch payouts v2 with idempotent re-submission

The single biggest pain point we heard from finance teams: "What happens if my batch upload errors halfway through?" The new payouts.batch.create accepts an idempotency key, holds the entire batch as a single atomic unit, and lets you resubmit safely. We never double-pay.

Re-submitting a 4,000-row CSV is now an idempotent, no-op operation if the batch already completed.

Webhook signatures upgraded to Ed25519

HMAC-SHA256 is still supported (and the default for older keys), but new sandbox keys mint with Ed25519 signatures. Verification cost dropped, key rotation got cleaner, and our internal load tests showed a 3× throughput increase on the verification path.

Changed

  • Invoice TTL default moved from 60 minutes to 90 seconds for fiat-anchored invoices. Stops stale-rate exploits. The 60-minute option is still available with expires_in: 3600.
  • Webhook retry curve is now exponential with jitter (was fixed-interval). Fewer thundering-herd incidents, longer tail recovery.
  • Dashboard nav rebuilt around four jobs instead of feature lists. Faster for new operators.

A note on EU MiCA Phase 2

Phase 2 of the EU's Markets in Crypto-Assets framework lands in stages through 2026. Two practical things change for our merchants:

  1. EUR-denominated invoices accepting non-MiCA-compliant stablecoins now require a disclosure surface in the checkout. We ship this automatically; no integration work required.
  2. The CASP licence path is now clear, and our EU-resident merchants can apply through our compliance partner. We'll publish a dedicated explainer next week.
mica · timeline
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MiCA Phase 2 timeline

Queued

  • Lightning Network invoices for sub-$100 payments (Q3 target)
  • Multi-sig payout approval flows for finance teams larger than 5
  • Postgres CDC export for merchants who want raw event streams in their data warehouse

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↳ end of articlehalfin journal · Apr 28, 2026