OCI-native file artifacts

Every file, provably authentic.

Sign and attest file archives in OCI registries. Carry cryptographic provenance wherever they go.

Get Started View on GitHub

99.99%less bandwidth on partial reads

Integrity LedgerSigned chain of custody

Signed

Sigstore signature

sig-2f9a

Manifest

Manifest digest

sha256:9d2f...c8e1

Index

Index blob digests

idx:3c91

Per-file

SHA256 on read

file:7b1e

The gap

You sign your container images. What about everything else?

Config files. ML models. Deployment artifacts. Certificates. They move between systems with no provenance, no integrity, and full downloads every time.

Unsigned fileNo provenance

Blob fileVerified

sha2561f8c...b91a

Trust, end-to-end

Make provenance visible, then prove it.

Blob turns file archives into verifiable, browsable artifacts that behave like container images.

Sigstore + SLSA

Prove origin

Attach signatures and attestations to file archives in OCI registries—then verify every file on read.

Per-file SHA256

Verify on read

Tamper with a single byte and verification fails instantly.

Range reads

Only fetch what you use

Browse and stream without downloading a 1GB archive.

SignedSigstore signature

ManifestDigest anchor

Index BlobFile map

Per-fileSHA256 on read

Every file inherits the signature above it.

Flow

Provenance Flow

Same guarantees as container images, for any file.

Build

GitHub Actions

Sign

Sigstore

Attest

SLSA provenance

Push

OCI registry

Pull

Consumer system

Verify + Extract

Policy checks on read

Example: GitHub Actions → GHCR → production host

Performance

Built for speed at file granularity.

Why download 1GB to read a 64KB config? Blob uses HTTP Range Requests to fetch exactly what you need, when you need it.

Overview
Detailed Benchmarks
vs eStargz

Traditional archive

1.0 GB

Blob range fetch

~65 KB

26 ns

lookup

43x

faster

99.99%

saved

API

Simple Go API

Push with signing in one call.Pull with policy enforcement and lazy reads.

// Push a directory to registry
c, _ := blob.NewClient(blob.WithDockerConfig())
c.Push(ctx, "ghcr.io/org/configs:v1", "./src")

// Pull with verification policies
sigPolicy, _ := sigstore.GitHubActionsPolicy("myorg/myrepo")
slsaPolicy, _ := slsa.GitHubActionsWorkflow("myorg/myrepo")

c, _ := blob.NewClient(
    blob.WithDockerConfig(),
    blob.WithPolicy(policy.RequireAll(sigPolicy, slsaPolicy)),
)

// Lazy load - only downloads what you read
archive, _ := c.Pull(ctx, "ghcr.io/org/configs:v1")
stats, _ := archive.CopyDir("./output", "configs/")
fmt.Printf("Extracted %d files
", stats.FileCount)