---
title: Provenance attestations
keywords: build, attestations, provenance, slsa, git, metadata
description: >
Provenance build attestations describe how and where your image was built.
aliases:
- /build/attestations/slsa-provenance/
---
The provenance attestations include facts about the build process, including
details such as:
- Build timestamps
- Build parameters and environment
- Version control metadata
- Source code details
- Materials (files, scripts) consumed during the build
Provenance attestations follow the
[SLSA provenance schema, version 0.2](https://slsa.dev/provenance/v0.2#schema).
For more information about how BuildKit populates these provenance properties, refer to
[SLSA definitions](slsa-definitions.md).
## Create provenance attestations
To create a provenance attestation, pass the `--attest type=provenance` option
to the `docker buildx build` command:
```console
$ docker buildx build --tag <namespace>/<image>:<version> \
--attest type=provenance,mode=[min,max] .
```
Alternatively, you can use the shorthand `--provenance=true` option instead of `--attest type=provenance`.
To specify the `mode` parameter using the shorthand option, use: `--provenance=mode=max`.
For an example on how to add provenance attestations with GitHub Actions, see
[Add attestations with GitHub Actions](/manuals/build/ci/github-actions/attestations.md).
## Mode
You can use the `mode` parameter to define the level of detail to be included in
the provenance attestation. Supported values are `mode=min` (default) and
`mode=max`.
### Min
In `min` mode, the provenance attestations include a minimal set of information,
such as:
- Build timestamps
- The frontend used
- Build materials
- Source repository and revision
- Build platform
- Reproducibility
Values of build arguments, the identities of secrets, and rich layer metadata is
not included `mode=min`. The `min`-level provenance is safe to use for all
builds, as it doesn't leak information from any part of the build environment.
The following JSON example shows the information included in a provenance
attestations created using the `min` mode:
```json
{
"_type": "https://in-toto.io/Statement/v0.1",
"predicateType": "https://slsa.dev/provenance/v0.2",
"subject": [
{
"name": "pkg:docker/<registry>/<image>@<tag/digest>?platform=<platform>",
"digest": {
"sha256": "e8275b2b76280af67e26f068e5d585eb905f8dfd2f1918b3229db98133cb4862"
}
}
],
"predicate": {
"builder": { "id": "" },
"buildType": "https://mobyproject.org/buildkit@v1",
"materials": [
{
"uri": "pkg:docker/docker/dockerfile@1",
"digest": {
"sha256": "9ba7531bd80fb0a858632727cf7a112fbfd19b17e94c4e84ced81e24ef1a0dbc"
}
},
{
"uri": "pkg:docker/golang@1.19.4-alpine?platform=linux%2Farm64",
"digest": {
"sha256": "a9b24b67dc83b3383d22a14941c2b2b2ca6a103d805cac6820fd1355943beaf1"
}
}
],
"invocation": {
"configSource": { "entryPoint": "Dockerfile" },
"parameters": {
"frontend": "gateway.v0",
"args": {
"cmdline": "docker/dockerfile:1",
"source": "docker/dockerfile:1",
"target": "binaries"
},
"locals": [{ "name": "context" }, { "name": "dockerfile" }]
},
"environment": { "platform": "linux/arm64" }
},
"metadata": {
"buildInvocationID": "c4a87v0sxhliuewig10gnsb6v",
"buildStartedOn": "2022-12-16T08:26:28.651359794Z",
"buildFinishedOn": "2022-12-16T08:26:29.625483253Z",
"reproducible": false,
"completeness": {
"parameters": true,
"environment": true,
"materials": false
},
"https://mobyproject.org/buildkit@v1#metadata": {
"vcs": {
"revision": "a9ba846486420e07d30db1107411ac3697ecab68",
"source": "git@github.com:<org>/<repo>.git"
}
}
}
}
}
```
### Max
The `max` mode includes all of the information included in the `min` mode, as
well as:
- The LLB definition of the build. These show the exact steps taken to produce
the image.
- Information about the Dockerfile, including a full base64-encoded version of
the file.
- Source maps describing the relationship between build steps and image layers.
When possible, you should prefer `mode=max` as it contains significantly more
detailed information for analysis.
> [!WARNING]
>
> Note that `mode=max` exposes the values of
> [build arguments](/reference/cli/docker/buildx/build.md#build-arg).
>
> If you're misusing build arguments to pass credentials, authentication
> tokens, or other secrets, you should refactor your build to pass the secrets using
> [secret mounts](/reference/cli/docker/buildx/build.md#secret) instead.
> Secret mounts don't leak outside of the build and are never included in provenance attestations.
## Inspecting Provenance
To explore created Provenance exported through the `image` exporter, you can
use [`imagetools inspect`](/reference/cli/docker/buildx/imagetools/inspect.md).
Using the `--format` option, you can specify a template for the output. All
provenance-related data is available under the `.Provenance` attribute. For
example, to get the raw contents of the Provenance in the SLSA format:
```console
$ docker buildx imagetools inspect <namespace>/<image>:<version> \
--format "{{ json .Provenance.SLSA }}"
{
"buildType": "https://mobyproject.org/buildkit@v1",
...
}
```
You can also construct more complex expressions using the full functionality of
Go templates. For example, for provenance generated with `mode=max`, you can
extract the full source code of the Dockerfile used to build the image:
```console
$ docker buildx imagetools inspect <namespace>/<image>:<version> \
--format '{{ range (index .Provenance.SLSA.metadata "https://mobyproject.org/buildkit@v1#metadata").source.infos }}{{ if eq .filename "Dockerfile" }}{{ .data }}{{ end }}{{ end }}' | base64 -d
FROM ubuntu:24.04
RUN apt-get update
...
```
## Provenance attestation example
<!-- TODO: add a link to the definitions page, imported from moby/buildkit -->
The following example shows what a JSON representation of a provenance
attestation with `mode=max` looks like:
```json
{
"_type": "https://in-toto.io/Statement/v0.1",
"predicateType": "https://slsa.dev/provenance/v0.2",
"subject": [
{
"name": "pkg:docker/<registry>/<image>@<tag/digest>?platform=<platform>",
"digest": {
"sha256": "e8275b2b76280af67e26f068e5d585eb905f8dfd2f1918b3229db98133cb4862"
}
}
],
"predicate": {
"builder": { "id": "" },
"buildType": "https://mobyproject.org/buildkit@v1",
"materials": [
{
"uri": "pkg:docker/docker/dockerfile@1",
"digest": {
"sha256": "9ba7531bd80fb0a858632727cf7a112fbfd19b17e94c4e84ced81e24ef1a0dbc"
}
},
{
"uri": "pkg:docker/golang@1.19.4-alpine?platform=linux%2Farm64",
"digest": {
"sha256": "a9b24b67dc83b3383d22a14941c2b2b2ca6a103d805cac6820fd1355943beaf1"
}
}
],
"buildConfig": {
"llbDefinition": [
{
"id": "step4",
"op": {
"Op": {
"exec": {
"meta": {
"args": ["/bin/sh", "-c", "go mod download -x"],
"env": [
"PATH=/go/bin:/usr/local/go/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
"GOLANG_VERSION=1.19.4",
"GOPATH=/go",
"CGO_ENABLED=0"
],
"cwd": "/src"
},
"mounts": [
{ "input": 0, "dest": "/", "output": 0 },
{
"input": -1,
"dest": "/go/pkg/mod",
"output": -1,
"mountType": 3,
"cacheOpt": { "ID": "//go/pkg/mod" }
},
{
"input": 1,
"selector": "/go.mod",
"dest": "/src/go.mod",
"output": -1,
"readonly": true
},
{
"input": 1,
"selector": "/go.sum",
"dest": "/src/go.sum",
"output": -1,
"readonly": true
}
]
}
},
"platform": { "Architecture": "arm64", "OS": "linux" },
"constraints": {}
},
"inputs": ["step3:0", "step1:0"]
}
]
},
"metadata": {
"buildInvocationID": "edf52vxjyf9b6o5qd7vgx0gru",
"buildStartedOn": "2022-12-15T15:38:13.391980297Z",
"buildFinishedOn": "2022-12-15T15:38:14.274565297Z",
"reproducible": false,
"completeness": {
"parameters": true,
"environment": true,
"materials": false
},
"https://mobyproject.org/buildkit@v1#metadata": {
"vcs": {
"revision": "a9ba846486420e07d30db1107411ac3697ecab68-dirty",
"source": "git@github.com:<org>/<repo>.git"
},
"source": {
"locations": {
"step4": {
"locations": [
{
"ranges": [
{ "start": { "line": 5 }, "end": { "line": 5 } },
{ "start": { "line": 6 }, "end": { "line": 6 } },
{ "start": { "line": 7 }, "end": { "line": 7 } },
{ "start": { "line": 8 }, "end": { "line": 8 } }
]
}
]
}
},
"infos": [
{
"filename": "Dockerfile",
"data": "RlJPTSBhbHBpbmU6bGF0ZXN0Cg==",
"llbDefinition": [
{
"id": "step0",
"op": {
"Op": {
"source": {
"identifier": "local://dockerfile",
"attrs": {
"local.differ": "none",
"local.followpaths": "[\"Dockerfile\",\"Dockerfile.dockerignore\",\"dockerfile\"]",
"local.session": "s4j58ngehdal1b5hn7msiqaqe",
"local.sharedkeyhint": "dockerfile"
}
}
},
"constraints": {}
}
},
{ "id": "step1", "op": { "Op": null }, "inputs": ["step0:0"] }
]
}
]
},
"layers": {
"step2:0": [
[
{
"mediaType": "application/vnd.docker.image.rootfs.diff.tar.gzip",
"digest": "sha256:261da4162673b93e5c0e7700a3718d40bcc086dbf24b1ec9b54bca0b82300626",
"size": 3259190
},
{
"mediaType": "application/vnd.docker.image.rootfs.diff.tar.gzip",
"digest": "sha256:bc729abf26b5aade3c4426d388b5ea6907fe357dec915ac323bb2fa592d6288f",
"size": 286218
},
{
"mediaType": "application/vnd.docker.image.rootfs.diff.tar.gzip",
"digest": "sha256:7f1d6579712341e8062db43195deb2d84f63b0f2d1ed7c3d2074891085ea1b56",
"size": 116878653
},
{
"mediaType": "application/vnd.docker.image.rootfs.diff.tar.gzip",
"digest": "sha256:652874aefa1343799c619d092ab9280b25f96d97939d5d796437e7288f5599c9",
"size": 156
}
]
]
}
}
}
}
}
```