---
id: specification-snapshot
title: "Specification snapshot"
description: "Append-only snapshots of service, action and link specifications. A write that changes a specification's watched fields mints a new snapshot, and content identical to the latest snapshot never mints twice. Snapshot ids are what package bills of materials pin as resource_revision_id, which freezes the exact specification content a package revision uses."
sidebar_label: Introduction
sidebar_position: 0
hide_title: true
custom_edit_url: null
---

import ApiLogo from "@theme/ApiLogo";
import Heading from "@theme/Heading";
import SchemaTabs from "@theme/SchemaTabs";
import TabItem from "@theme/TabItem";
import Export from "@theme/ApiExplorer/Export";

<span
  className={"theme-doc-version-badge badge badge--secondary"}
  children={"Version: 1.0.0"}
>
</span>

<Heading
  as={"h1"}
  className={"openapi__heading"}
  children={"Specification snapshot"}
>
</Heading>



Append-only snapshots of service, action and link specifications. A write that changes a specification's watched fields mints a new snapshot, and content identical to the latest snapshot never mints twice. Snapshot ids are what package bills of materials pin as resource_revision_id, which freezes the exact specification content a package revision uses.

<div
  style={{"marginBottom":"2rem"}}
>
  <Heading
    id={"authentication"}
    as={"h2"}
    className={"openapi-tabs__heading"}
    children={"Authentication"}
  >
  </Heading><SchemaTabs
    className={"openapi-tabs__security-schemes"}
  >
    <TabItem
      label={"HTTP: Bearer Auth"}
      value={"bearerAuth"}
    >
      
      
      
      
      <div>
        <table>
          <tbody>
            <tr>
              <th>
                Security Scheme Type:
              </th><td>
                http
              </td>
            </tr><tr>
              <th>
                HTTP Authorization Scheme:
              </th><td>
                bearer
              </td>
            </tr><tr>
              <th>
                Bearer format:
              </th><td>
                JWT
              </td>
            </tr>
          </tbody>
        </table>
      </div>
    </TabItem>
  </SchemaTabs>
</div>