On the JVM, Log.d / .i / .w / .e were printing through \`println()\` which
lands on stdout. The amy CLI uses stdout as its JSON contract — any
Marmot/MLS command would restore state, emit a burst of DEBUG lines,
then emit the JSON object, and every caller piping through jq failed
to parse because the first non-empty line was a log line.
Switch to \`System.err.println\` inside PlatformLog.jvm.kt. Conventional
for CLIs (data on stdout, diagnostics on stderr), and the desktop app
already redirects as part of packaging. Callers who want everything
mixed can still \`2>&1\` at the shell level.
Fixes amy marmot group create / group add / message send etc. when
their output is captured by a shell script.
https://claude.ai/code/session_01M6dCKAF5Y1VyHGZPjzwDXq
Three SHA-256 implementations benchmarked on the same phone:
- sha256Android: Android's MessageDigest (BoringSSL + ARM64 CE hardware)
- sha256OurC: Our C SHA-256 (ARM64 CE hardware via JNI)
- sha256Kotlin: Kotlin's sha256 (platform MessageDigest on Android)
Also add nativeSha256 JNI method to expose our hardware SHA-256.
Why our C matches ACINQ on ARM64 despite different architectures:
- Our 4x64: 16 MUL+UMULH pairs per field mul
- ACINQ 5x52: 25 MUL+UMULH pairs per field mul
- We save 9 multiply pairs (~27ns on Cortex-X3) per fe_mul
- ACINQ saves ~6 normalizations with lazy reduction (~6ns)
- Net advantage: ~21ns per mul × 500 muls/verify > 0
- Plus our SHA-256 uses hardware CE, ACINQ's is software
https://claude.ai/code/session_011KVZhDcV2G7idNWEBz12GY
Add a complete C implementation of secp256k1 elliptic curve operations
alongside the existing Kotlin implementation, enabling direct comparison
and extraction of maximum performance from each platform (ARM64, x86_64).
C Implementation (quartz/src/main/c/secp256k1/):
- field.h/c: 5x52-bit limb field arithmetic with __int128 support and
lazy reduction (12-bit headroom per limb vs Kotlin's fully-packed 4x64)
- scalar.h/c: Scalar mod n arithmetic, GLV decomposition, wNAF encoding
- point.h/c: Jacobian point operations (3M+4S double, 8M+3S mixed add),
GLV+wNAF scalar multiplication, Strauss/Shamir dual scalar multiply,
Montgomery batch-to-affine, precomputed G tables (wNAF-12)
- schnorr.c: BIP-340 Schnorr sign/verify/verifyFast/verifyBatch with
pubkey decompression cache and precomputed tag hash prefixes
- sha256.c: Self-contained SHA-256 for BIP-340 tagged hashes
- secp256k1_c.h: Public API matching the Kotlin Secp256k1 object
- jni_bridge.c: JNI bridge for JVM/Android integration
- benchmark.c: Standalone C benchmark (cmake build)
- CMakeLists.txt: Build system with ARM64/x86_64 optimization flags
Kotlin Integration:
- Secp256k1InstanceC: expect/actual wrapper (commonMain/jvmMain/androidMain/nativeMain)
- Secp256k1C: JVM JNI binding class
- Secp256k1TripleBenchmark: Three-way JVM benchmark (ACINQ vs Kotlin vs Custom C)
- Secp256k1CBenchmark: Android benchmark for the C implementation
Current status: sign works correctly (verified against BIP-340 test vectors),
verify path needs ecmult_double_g debugging (GLV wNAF-12 table issue). The
comb table for ecmult_gen also needs fixing (currently falls back to GLV+wNAF).
Field arithmetic is fully verified: 5x52 limbs with R=0x1000003D10 fold.
https://claude.ai/code/session_011KVZhDcV2G7idNWEBz12GY
Full migration of the secp256k1 library from LongArray(4)/LongArray(8)
to Fe4/Wide8 struct types with @JvmField named Long fields. This
eliminates all array bounds checks from the hot path.
Files migrated (13 source + 7 test + 2 benchmark):
- U256.kt, FieldP.kt, ScalarN.kt, Glv.kt, ECPoint.kt
- FieldMulPlatform.kt (expect + 3 actuals), FieldMulFused.kt
- PointTypes.kt (MutablePoint, AffinePoint, PointScratch)
- KeyCodec.kt, Secp256k1.kt
- All test files and benchmarks
Bytecode impact:
Before: 464 laload/lastore (bounds-checked) in core arithmetic
After: 0 laload/lastore, all getfield/putfield (no checks)
The public API (Secp256k1 object) is unchanged - it still accepts
and returns ByteArray. Fe4 conversion happens at the API boundary
via U256.fromBytes()/U256.toBytes().
All secp256k1 unit tests pass on JVM.
https://claude.ai/code/session_01Sxi6Gpxbstuj3Y8TBY7XrU
BIP-340 public keys always have even y, so the y-parity prefix byte
(0x02) is redundant when the caller already has the 32-byte x-only
pubkey. This new overload takes the x-only pubkey directly, avoiding:
1. The expensive G multiplication to derive the pubkey (~20μs on Android)
2. The 33→32 byte array copy that signSchnorrWithPubKey does internally
Added to:
- Secp256k1.signSchnorrWithXOnlyPubKey (core implementation)
- Secp256k1Instance (expect/actual, falls back to C lib's signSchnorr
since the native C lib always derives pubkey internally)
- Secp256k1InstanceOurs (uses the optimized pure-Kotlin path)
- Nip01Crypto.signWithPubKey (app-level convenience)
The app's KeyPair already stores the 32-byte x-only pubkey. Callers
like EventAssembler.hashAndSign can pass it through to skip the
G multiplication entirely.
https://claude.ai/code/session_01EMY5RnXb9rnsyU2KbXrSaY
The fused fieldMulReduceWith + crossinline lambda was designed for ART
which struggles with deep call chains. On HotSpot C2, it creates a
2351-bytecode method (exceeding FreqInlineSize=325) that can't be
inlined into FieldP.mul, and wastes 180 bytecodes on lambda param
shuffling that C2 must clean up.
The unfused path (U256.mulWide + FieldP.reduceWide) produces a tiny
40-bytecode fieldMulReduce that HotSpot easily inlines. HotSpot's 8+
level inlining depth handles the full chain down to the
Math.unsignedMultiplyHigh intrinsic (single MULQ on x86-64).
Benchmark on JVM 21 x86-64: equivalent performance (1.5× verify,
0.9× sign-cached vs native C). Cleaner bytecode with no lambda waste.
https://claude.ai/code/session_01EMY5RnXb9rnsyU2KbXrSaY
Document WHY each approach was chosen, what alternatives were tested,
and what the measured impact was — so future contributors don't
accidentally revert optimizations or repeat failed experiments.
Key decisions documented:
- uLt() expect/actual: why XOR on Android, Long.compareUnsigned on JVM,
and why a shared inline fun in commonMain caused 30% JVM regression
- fieldMulReduceWith: why fused mul+reduce, why inline+crossinline,
why NOT 5x52 limbs, why NOT single-method with all API branches
- @JvmField: why it's required on MutablePoint/AffinePoint/PointScratch,
with bytecode counts showing ~7,450 + ~2,000 virtual getter calls
eliminated per verify
https://claude.ai/code/session_01EMY5RnXb9rnsyU2KbXrSaY
On Android (ART), the unsignedMultiplyHigh wrapper function has per-call
branching for API level detection that prevents ART's JIT from inlining
the intrinsic into the hot loop. This creates ~10,000 extra function
calls per signature verify (20 wrapper calls × 500 field muls).
This commit introduces fieldMulReduce/fieldSqrReduce as expect/actual
functions that fuse U256.mulWide + FieldP.reduceWide into a single
compilation unit. The multiply-high intrinsic is passed as a crossinline
lambda and inlined at each call site, producing platform-specific code
with zero wrapper overhead:
- Android API 35+: Math.unsignedMultiplyHigh inlined directly (UMULH)
- Android API 31-34: Math.multiplyHigh + correction inlined (SMULH)
- Android API <31: pure-Kotlin fallback inlined
- JVM: Math.unsignedMultiplyHigh inlined directly
- Native: pure-Kotlin fallback inlined
The API level check happens ONCE per fieldMulReduce call (outermost
branch) rather than per multiply-high call (innermost loop), so ART
profiles and JIT-compiles only the hot path.
https://claude.ai/code/session_01EMY5RnXb9rnsyU2KbXrSaY
ThreadLocal.withInitial is a JVM-only API that doesn't compile on
Kotlin/Native or iOS targets. Replace all usages in commonMain
(FieldP.kt, Point.kt) with a new ScratchLocal expect/actual:
- jvmMain/androidMain: delegates to java.lang.ThreadLocal (same behavior)
- nativeMain: holds value directly (Kotlin/Native coroutines are
cooperative, scratch buffers don't need thread isolation)
https://claude.ai/code/session_01BhU63WUe9AhikZxRdw3Lpg
The JVM target is Java 21, so Math.unsignedMultiplyHigh (Java 18+) can
be called directly without MethodHandle reflection. The previous approach
used MethodHandle.invokeExact which Kotlin compiles with Object return
type, causing Long boxing on every call (3 box/unbox per invocation ×
16 calls per field multiply = 48 boxed objects per mul).
Direct call compiles to a single UMULH instruction with zero overhead.
This is the most performance-critical function: called ~12,000× per
signature verification.
https://claude.ai/code/session_01BhU63WUe9AhikZxRdw3Lpg
Foundation layer for the 4×64-bit limb optimization. This commit rewrites
U256 from IntArray(8) to LongArray(4) and adds platform-specific
Math.multiplyHigh for 64×64→128-bit products:
- JVM: Math.multiplyHigh intrinsic (single IMULH/SMULH instruction)
- Android API 31+: Math.multiplyHigh, fallback to pure Kotlin on older
- Native: pure Kotlin fallback (4 sub-products per multiplyHigh call)
The 4×64 representation reduces inner products from 64 to 16 per field
multiply on JVM, a potential ~1.5-2× speedup on the critical path.
NOTE: This commit intentionally breaks the build — FieldP, ScalarN, Glv,
Point, KeyCodec, Secp256k1, and all tests still expect IntArray(8).
They will be updated in subsequent commits.
https://claude.ai/code/session_01BhU63WUe9AhikZxRdw3Lpg
Implements all secp256k1 operations used by Secp256k1Instance in pure Kotlin,
eliminating the dependency on native secp256k1 bindings (fr.acinq.secp256k1-kmp).
Implementation:
- Field.kt: 256-bit unsigned integer arithmetic, field mod p, scalar mod n
- Point.kt: EC point operations (Jacobian coords), point parsing/serialization
- Secp256k1.kt: Public API - pubkeyCreate, pubKeyCompress, secKeyVerify,
signSchnorr/verifySchnorr (BIP-340), privKeyTweakAdd, pubKeyTweakMul
Tests (36 total):
- All 19 BIP-340 test vectors (signing vectors 0-3, 15-18; verify vectors 4-14)
- ACINQ test vectors for key creation, compression, secKeyVerify, privKeyTweakAdd,
pubKeyTweakMul
- ECDH symmetry and sign/verify round-trip tests
Secp256k1Instance is now a concrete object in commonMain instead of expect/actual,
delegating to the pure-Kotlin implementation. All existing NIP-44 and BIP-32 tests
pass with the new implementation.
https://claude.ai/code/session_01BhU63WUe9AhikZxRdw3Lpg
- Extract private log() helper in JVM and iOS PlatformLog to reduce
copy-paste branching
- Fix JVM formatter to be private and non-nullable
- Convert 60+ interpolated Log.w/e/i calls to lambda overloads,
including hot-path Filter.kt toJson() and LocalCache event processing
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
- Add optional throwable parameter to d() and i() across all platforms
- Add inline lambda overloads for all log levels to defer message
construction, avoiding string allocation when level is filtered
- Restore VoiceMessagePreview to pass throwable directly
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
- Fully converts OpenTimestamp Java codebase to Kotlin, migrating the sync and async HTTP call interfaces to OkHttp and coroutines
- Redesigns parsing of relay commands, messages and filters for performance in Jackson.
- Starts the use of KotlinX Serialization when speed is not a requirement
- Migrates all Jackson field annotations to Kotlin Serialization
- Migrates Regex use in Quarts to Kotlin's Regex class
- Migrates Base64 from Android to Kotlin
- Migrates UUID from Android/Java to Kotlin
- Migrates LRUCache usage from Android/Java to Kotlin collections
- Migrates all String to bytearray conversions to Kotlin methods
- Migrates all System.arraycopy calls to kotlin native ones.
- Separates parsing code from the data classes Companion objects
- Exposes Rfc3986 normalizations to each platform.
- Exposes URI parsing classes to each platform.
- Exposes URL Encoders to each platform.
- Exposes BigDecimal to each platform.
- Exposes the Url Detector to each platform.
- Exposes MacInstances to each platform
- Exposes Diggest instances to each platform.
- Exposes a BitSet to each platform.
- Exposes GZip to each platform.
- Exposes Secp256k1 to each platform.
- Exposes SecureRandom to each platform.
- Exposes Time in seconds to each platform.
- Exposes the LargeCache to each platform.
- Exposes AES CBC and AES GCM encryption/decryption to each platform
- Migrate test assertions to Kotlin Tests
- Exposes Address class to each platform because of the Parceleable
- Creates our own ByteArrayOutputStream.
- Removes Lock features inside the Bloomfilters because we don't need data consistency/
- Migrates UserMetadata parser from Jackson to Kotlin serialization
- Removes the need for Static methods in each tag.
- Adds an event template serializer
- Adds KotlinX Datetime to migrate some of the date-based logs
- Adds support for LibSodium in the JVM platform
- Creates a shared test build for iOS targets
- Fixes several usages of Reflection when serializing classes
- Fixes a bug on loading RelayDB for the HintBloom filter test
- Increases the Bloom filter space to better use hints in the app.
- Removes support for iOS in x86
- Creates a Jackson mapper just for NIP-55, which stays in the Android build only.
- Keeps the event store in the android build as well.
- Removes @Syncronized tags in favor of Mutexes.
- Improved sendAndWaitForResponse NostrClient method to properly account for returns from each relay.
- Removes the need for GlobalScope and async calls in the downloadFirstEvent method.
- Restructures the parser and serialization of the relay messages and commands for performance with Jackson
- Removes the dependency on Jackson's error classes across the codebase.
- Moves the hint to quote tag extension methods to their own packages.
- Speeds up the generation of Bech32 addresses
- Migrates NIP-6 and Blossom uploads to use Kotlin Serialization
Claude