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Pranay Prakash 5f0b845211 RFC: compress serialized payload refs — zstd (gzip fallback), specVersion 5 (#2394)
* feat(core,world): gzip-compress serialized payloads behind specVersion 5

Add a composable 'gzip' format prefix layer to the serialization
pipeline (compress before encrypt: encr(gzip(devl))), cutting stored
payload bytes by ~70-87% on real-world-style workloads. Compression is
gated on run specVersion 5 (new SPEC_VERSION_SUPPORTS_COMPRESSION) and
on target-deployment capabilities for cross-deployment writes; payloads
under 1KB or that don't compress meaningfully are stored unchanged.
Reads dispatch on the format prefix so both compressed and uncompressed
data are always readable. WORKFLOW_DISABLE_COMPRESSION=1 disables
writes.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* test(core): add CPU/perf compression benchmark + shared workloads

Split the compression benchmark into reproducible size and CPU scripts
sharing deterministic workloads (lib/workloads.mjs). The CPU benchmark
measures serialize/deserialize overhead per payload, total CPU across
thousands of events, and compares gzip levels/brotli/deflate. Documents
how to run the size, CPU, and end-to-end (bench.bench.ts) benchmarks
against local and Vercel in scripts/README.md.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* feat(world-vercel): advertise specVersion 5 to enable compression on Vercel

Now that workflow-server declares spec-5 support (vercel/workflow-server#520),
bump the Vercel world's advertised specVersion from 4 to 5 so new Vercel runs
are stamped spec 5 and become eligible for gzip payload compression. Payloads
stay opaque to the server (compression is client-side); spec 5 is a superset of
spec 4, so initial run attributes still work.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* feat(core): emit OTel span attributes for compression impact

Track gzip payload compression on both the serialize (write) and
deserialize (read) paths via span attributes:
workflow.serialization.{operation,compressed,uncompressed_bytes,
stored_bytes,compression_ratio}. Sizes are measured at the compression
boundary (pre-encryption), so they reflect compression's effect rather
than the at-rest size.

The compression codec stays pure — compress/decompress optionally
populate a CompressionStats sink, threaded through CodecOptions to the
mode serializers and read by the dehydrate/hydrate wrappers, which set
attributes on the active span. Telemetry failures are swallowed so they
can never break the serialize/deserialize data path.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* feat(core,web-shared): prefer zstd compression codec (gzip fallback)

Switch the payload compression codec to zstd, which benchmarks 3–7×
faster than gzip at an equal-or-better ratio on representative workloads
(compression runs at every step boundary, so the write CPU is a per-step
tax). zstd uses node:zlib (>= 22.15); gzip via the portable
CompressionStream remains the fallback when zstd is unavailable, and
WORKFLOW_COMPRESSION_CODEC=gzip forces it. Reads dispatch on the format
prefix, so 'zstd' and 'gzip' payloads are both always decodable.

zstd is Node-only (Web CompressionStream has no zstd), so the browser
o11y read path registers a WASM-backed decoder (@tootallnate/zstd-wasm)
via a new registerZstdDecoder hook; node:zlib handles Node-side reads
(runtime replay, CLI, server o11y). A new workflow.serialization.codec
span attribute reports which codec applied. gzip and zstd read support
co-ship, so the existing specVersion-5 capability gate is unchanged.

Verified end-to-end: spec-5 runs store zstd-prefixed payloads on disk
and replay/complete correctly; the WASM decoder round-trips node:zlib
zstd output. Benchmarks updated to compare zstd vs gzip.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
2026-06-16 23:27:47 +00:00
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