oras manifest fetch

Fetch a manifest from a registry.

Synopsis 

oras manifest fetch <reference> [options]

Description

The manifest fetch command downloads an OCI manifest from a registry. The manifest contains metadata about the artifact, including layer digests, annotations, and artifact type.

Arguments

<reference>

Manifest reference in the format [registry/]repository[:tag|@digest].

Examples:

  • ghcr.io/myorg/app:v1.0 (by tag)
  • ghcr.io/myorg/app@sha256:abc123... (by digest)

Options

Output Options

--output <file>, -o

Write manifest to file instead of stdout.

Example: --output ./manifest.json

--descriptor

Output the manifest descriptor (metadata) instead of manifest content.

The descriptor includes media type, size, digest, and platform information.

--pretty

Pretty-print the JSON output with indentation.

By default, manifests are printed as compact JSON.

Platform Options

--platform <os/arch>

Select platform for multi-platform images (e.g., linux/amd64, linux/arm64).

When fetching an image index (multi-platform image), this returns the platform-specific manifest.

Remote Options

--username <username>, -u

Registry username.

--password <password>, -p

Registry password.

--password-stdin

Read password from stdin.

--insecure

Skip TLS certificate verification.

--plain-http

Use HTTP instead of HTTPS.

--ca-file <file>

Path to custom CA certificate.

--registry-config <file>

Path to registry configuration file (default: ~/.docker/config.json).

Common Options

--debug, -d

Enable debug logging to stderr.

--verbose, -v

Enable verbose output.

Examples

Fetch manifest to stdout 

oras manifest fetch ghcr.io/myorg/app:v1.0

Output (compact JSON):

{"schemaVersion":2,"mediaType":"application/vnd.oci.image.manifest.v1+json","config":{...},"layers":[...]}

Fetch manifest with pretty printing 

oras manifest fetch ghcr.io/myorg/app:v1.0 --pretty

Output (formatted JSON):

{
  "schemaVersion": 2,
  "mediaType": "application/vnd.oci.image.manifest.v1+json",
  "config": {
    "mediaType": "application/vnd.oci.image.config.v1+json",
    "digest": "sha256:config123...",
    "size": 1234
  },
  "layers": [
    {
      "mediaType": "application/vnd.oci.image.layer.v1.tar+gzip",
      "digest": "sha256:layer123...",
      "size": 5678
    }
  ]
}

Fetch manifest to file 

oras manifest fetch ghcr.io/myorg/app:v1.0 --output ./manifest.json

Fetch manifest descriptor 

oras manifest fetch ghcr.io/myorg/app:v1.0 --descriptor

Output:

{
  "mediaType": "application/vnd.oci.image.manifest.v1+json",
  "digest": "sha256:abc123...",
  "size": 1234
}

Fetch specific platform manifest 

oras manifest fetch ghcr.io/myorg/multiplatform:latest --platform linux/arm64

Fetch by digest 

oras manifest fetch ghcr.io/myorg/app@sha256:abc123... --pretty

Fetch and pipe to jq 

oras manifest fetch ghcr.io/myorg/app:v1.0 | jq '.layers[].digest'

Output:

"sha256:layer1..."
"sha256:layer2..."
"sha256:layer3..."

Exit Codes

  • 0 — Success (manifest written to output)
  • 1 — Network error, registry error, manifest not found
  • 2 — Usage error (invalid reference)

Notes

  • Use --pretty for human-readable output
  • Use --descriptor to get metadata without downloading the full manifest
  • For multi-platform images, use --platform to select a specific variant
  • Manifest content is JSON and can be piped to tools like jq for processing
  • Without --output, writes to stdout (redirect to save to file)

Manifest Structure

OCI manifests typically contain:

  • schemaVersion: Manifest schema version (usually 2)
  • mediaType: Manifest media type
  • config: Reference to configuration blob
  • layers: Array of layer descriptors (blobs)
  • annotations: Optional key-value metadata

See Also