Files
vercel__workflow/.changeset/gzip-ref-compression-core.md
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

674 B

@workflow/core
@workflow/core
minor

Compress serialized payloads (step inputs/outputs, workflow arguments/return values, errors, hook payloads) before storage using composable codec format prefixes. zstd is the preferred codec (markedly faster than gzip at an equal-or-better ratio, via node:zlib); gzip (CompressionStream) is the portable fallback when zstd is unavailable. Reads dispatch on the prefix, so both codecs are always decodable. Compression is applied before encryption, gated on run specVersion 5, and skipped for small or incompressible payloads. WORKFLOW_DISABLE_COMPRESSION=1 disables writes; WORKFLOW_COMPRESSION_CODEC=gzip forces the portable codec.