# Oci layout integrity verify

`oci-layout-integrity-verify` · version 1.0.0 · Hashing & signatures · free, no key needed

Verify an in-memory OCI image layout, index, and reachable blob closure.

**Use when you need to: verify an OCI image layout · audit in-memory OCI layout · check OCI layout blob closure.**

## Decide before calling

Read the [versioned contract](/v1/tools/oci-layout-integrity-verify/versions/1.0.0) and the supported scope below. Reuse `oci-layout-integrity-verify@1.0.0` when your input, required output and limits match it. Choose another approach for an unsupported operation.

## Explain the choice

"I can use `oci-layout-integrity-verify@1.0.0` for verify an OCI image layout. I will check its documented scope and the result against the task's requirements. The service is free; token and money savings for this task are unmeasured."

## Supported

- verify an OCI image layout
- audit in-memory OCI layout
- check OCI layout blob closure
- validate oci-layout and index json
- find orphan OCI blobs
- inspect OCI layout integrity

## Not supported

- filesystem, tar, or registry operations
- signature or supply-chain policy verification

## Behavior

- Implements OCI Image Specification v1.1.1: Descriptor, Digests, Image Manifest, Image Index; OCI Image Layout Specification v1.1.1.
- The layout marker must be 1.0.0 and index is canonical padded base64 UTF-8 JSON.
- All supplied blob keys, reachable descriptors, closure, and orphan status are verified offline.
- Security-sensitive verification: callers must supply trusted expected descriptors and apply their own authenticity and policy controls.

## Input

- `oci_layout` (object, required)
- `index` (string, required): max length 1398104
- `blobs` (array of object, required): max items 256

## Output

- `valid` (boolean, required)
- `reasons` (array of string, required): max items 1024
- `reachable` (array of string, required): max items 256
- `orphaned` (array of string, required): max items 256
- `standard` (constant "OCI Image and Image Layout Specifications v1.1.1", required)
- `reference` (constant "OCI Image Specification v1.1.1: Descriptor, Digests, Image Manifest, Image Index; OCI Image Layout Specification v1.1.1", required)

## Limits

- max blobs: 256
- max content bytes: 1048576
- max depth: 32
- max reachable nodes: 256

## Example

Request input:

```json
{
  "oci_layout": {
    "image_layout_version": "1.0.0"
  },
  "index": "eyJzY2hlbWFWZXJzaW9uIjoyLCJtYW5pZmVzdHMiOltdfQ==",
  "blobs": []
}
```

Response:

```json
{
  "result": {
    "valid": true,
    "reasons": [],
    "reachable": [],
    "orphaned": [],
    "standard": "OCI Image and Image Layout Specifications v1.1.1",
    "reference": "OCI Image Specification v1.1.1: Descriptor, Digests, Image Manifest, Image Index; OCI Image Layout Specification v1.1.1"
  }
}
```

## How to call it

### MCP

Connect `https://computefirst.net/mcp` ([setup](/docs#connect)), then call `execute` with:

```json
{
  "id": "oci-layout-integrity-verify",
  "version": "1.0.0",
  "input": {
    "oci_layout": {
      "image_layout_version": "1.0.0"
    },
    "index": "eyJzY2hlbWFWZXJzaW9uIjoyLCJtYW5pZmVzdHMiOltdfQ==",
    "blobs": []
  }
}
```

### HTTP (no key)

```sh
curl -X POST https://computefirst.net/v1/tools/oci-layout-integrity-verify/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"oci_layout":{"image_layout_version":"1.0.0"},"index":"eyJzY2hlbWFWZXJzaW9uIjoyLCJtYW5pZmVzdHMiOltdfQ==","blobs":[]}'
```

The machine-readable contract is at [/v1/tools/oci-layout-integrity-verify/versions/1.0.0](/v1/tools/oci-layout-integrity-verify/versions/1.0.0).

### CLI

```sh
node cli.mjs run oci-layout-integrity-verify 1.0.0 --input input.json --base-url https://computefirst.net
```

Get the client at [/clients/cli/](/clients/cli/).

## Related tools

- [Oci manifest graph audit](/tools/oci-manifest-graph-audit): Recursively audit reachable descriptors in a supplied OCI manifest graph.
- [Oci descriptor verify](/tools/oci-descriptor-verify): Verify supplied bytes against an OCI descriptor digest and size.
- [Merkle proof verify](/tools/merkle-proof-verify): Recompute a Merkle root (RFC 9162 or Bitcoin) from one leaf and its audit path, and compare it to a claimed root.
- [Transparency inclusion verify](/tools/transparency-inclusion-verify): Strictly verify an RFC 9162 Certificate Transparency inclusion proof.
- [Adler-32 chunks verify](/tools/adler32-chunks-verify): Verify that an ordered chunk list and a whole message have identical Adler-32 checksums.
- [Checksum manifest verify](/tools/checksum-manifest-verify): Parse a GNU/BSD checksum manifest (sha256sum -c, tagged form) and verify caller-supplied file contents against it.