Prebuilt binaries

Upstream stopped publishing standalone Hermes VM binaries as GitHub release assets in August 2024, at v0.13.0. Tags keep flowing but carry no assets, and modern upstream CI builds the VM for macOS only.

Building from source is cheap and exact, so Argus builds its own and publishes them.

Published platforms

Platform	Asset
darwin-arm64	hermes-<version>-darwin-arm64.tar.gz
darwin-x64	hermes-<version>-darwin-x64.tar.gz
linux-x64	hermes-<version>-linux-x64.tar.gz
linux-arm64	hermes-<version>-linux-arm64.tar.gz

Windows is absent deliberately — it needs a different toolchain and a different binary layout (.exe, bundled ICU DLLs), and no part of Argus is verified on it yet. On Windows, use --provision or name a binary with --hermes.

Each archive holds three executables:

File	What it is
hermes	The VM. Runs JavaScript or compiled bytecode.
hermesc	The compiler. Emits HBC bytecode.
hvm	The bytecode-only VM.

Releases, not npm

The releases are tagged hermes-bin-v<hermes version> — versioned by the Hermes version, not the Argus version. No Argus package depends on them.

That is the whole point. npm versions a package once, at publish time. Which Hermes binary you need depends on your project: React Native 0.83 wants 250829098.0.4 and 0.86 wants 250829098.0.16, with the same Argus installed for both. A dependency fixed at publish time cannot express that.

This is where Argus differs from the esbuild model, which pins one binary per esbuild release — esbuild only ever needs one.

A release on a public repository also needs no authentication to download, has no practical size limit, and is CDN-served. npm stays reserved for the Argus code packages, which is a separate concern.

The hermes-bin-v prefix keeps the two tag namespaces separable: Argus tags its own releases v0.1.0, and both live on the same repository. A hyphen rather than a slash keeps the tag usable verbatim in an asset URL path.

Verifying

Every asset ships a .sha256 next to it, and checksums.txt covers the whole release:

shasum -a 256 -c checksums.txt

The two are redundant by design: the aggregate is what a human verifies the whole release with in one command; the per-asset file is what the provisioning chain fetches when it wants exactly one archive and should not pay for the others.

Argus verifies the checksum on download before it trusts an archive, and extracts through a temporary directory so an interrupted run cannot leave a half-populated cache entry behind.

The parity gate

Every published build is gated on bytecode parity with the official compiler React Native ships: the same source compiled by our hermesc and by hermes-compiler@<version> must produce a byte-identical .hbc.

That is what makes “the same engine” a checkable claim rather than a marketing line. A build that fails the gate is not published.

Downloading by hand

You do not need to. Argus fetches the right one at run time and caches it under ~/.argus/cache/.

If you want one anyway — an air-gapped machine, a container image, a shared CI cache:

curl -LO https://github.com/malopezr7/argus/releases/download/hermes-bin-v250829098.0.16/hermes-250829098.0.16-linux-x64.tar.gz
curl -LO https://github.com/malopezr7/argus/releases/download/hermes-bin-v250829098.0.16/checksums.txt
shasum -a 256 -c checksums.txt --ignore-missing

tar xzf hermes-250829098.0.16-linux-x64.tar.gz
argus --hermes ./hermes "src/**/*.test.ts"

The asset name carries the version as well as the platform even though the release tag already pins it — assets get downloaded, renamed by browsers, and pasted into issue reports detached from the release they came from, and a bare linux-x64.tar.gz is unidentifiable once that happens.

Licensing

Hermes is MIT licensed. These builds statically link llvh, a fork of LLVM vendored in the Hermes tree, covered by Apache-2.0 WITH LLVM-exception. Argus itself is MIT.

What is published today

One release so far:

Release	Engine	Covers	Platforms
hermes-bin-v250829098.0.16	V1	React Native 0.86 and 0.87	all four

Every other pinned version is publishable but not yet cut. Until its release exists, the prebuilt step reports a 404 and the chain falls through to the bundled VM or --provision — see the version table for which React Native releases that affects and the roadmap for the rest of the matrix.