Overview8,061 ✅ SwiftUI1,326 ✅ Stdlib691 ✅ Foundation198 ✅ Metal106 kw · 90+ builtins

What actually works

Counted from per-API matrices checked against the real Apple SDK — not asserted. ✅ means it compiles and runs. 🟡 means the common paths work and the edges don't.

Solid — write normal Swift against these3 frameworks

Core Data 1,111 ✅ · 100%

ImageIOReal pixel decode — PNG, JPEG and friends 770 ✅ · 93%

Compressionzlib · LZFSE · Brotli · LZMA byte-identical to Apple 67 ✅ · 93%

Strong — most of what you'd reach for6 frameworks

SwiftUICompiled to UIIR and painted by a real renderer — no JS reimplementation 1,326 ✅ · 1,410 🟡

SwiftData 445 ✅ · 73%

Swift stdlib 691 ✅ · 381 🟡

Core Image 431 ✅ · 265 🟡

CoreFoundationIncluding the toll-free bridge to Foundation 822 ✅ · 38%

Observation 29 ✅ · 19 🟡

Partial — the common paths11 frameworks

UIKit 1,607 ✅ · 19%

System 164 ✅ · 35%

Foundation 198 ✅ · 333 🟡

Accelerate 108 ✅ · 2%

simd 100 ✅ · 51 🟡

Core Graphics 65 ✅ · 5%

Combine 56 ✅ · 5%

AVFAudioWAV and FLAC decode, bit-identical to Apple 28 ✅ · 3%

Apple Archive 25 ✅ · 5%

AlarmKit 10 ✅ · 5%

QuickLook Thumbnailing 8 ✅ · 14%

MetalShader compiler — MSL → WGSL, counted separately from the API matrices 106 kw · 90+ builtins

How to read these numbers

Read the ✅ count, not the percentage

Percentages are against Apple's entire published surface — deprecated members, platform variants, initialisers nobody calls. Accelerate is 7,127 rows; UIKit is 8,467. 1,607 working UIKit APIs is a lot of UIKit, even at 19%.

The matrices are machine-checked

A guard script asserts every matrix's TOTAL row agrees with the rows above it. A matrix that overstates coverage is worse than no matrix — it is what planning decisions get made from.

374 frameworks are catalogued, not started

AppIntents, Contacts, EventKit, CallKit and the rest have their API surface mapped with matrices generated and nothing behind them. They are measured so the gap is known, not because they are close.

Two denominators exist

Per-framework pages measure against Apple's full surface; the in-repo matrices measure the surface MiniSwift targets. Where they differ, the number shown here is the one on the page it links to.