> ## Documentation Index > Fetch the complete documentation index at: https://docs.barndoor.ai/llms.txt > Use this file to discover all available pages before exploring further. # Get Policy Revision > Return a single policy revision by ID, scoped to the given policy. ## OpenAPI ````yaml /api-reference/openapi.yaml get /api/policy/v2/policies/{policy_id}/revisions/{revision_id} openapi: 3.1.0 info: title: Barndoor.ai Public API description: Unified public API specification for Barndoor.ai platform version: 2.18.0 servers: - url: https://{host} description: Barndoor public API variables: host: default: platform.barndoor.ai description: >- The host serving your Barndoor deployment. Defaults to production; override it for another environment or a dedicated deployment. security: - ApiKey: [] - OAuth2: - openid - profile - email tags: - name: dlp x-group: Data Control Center - name: identity x-group: Identity - name: llm-gateway x-group: LLM Gateway - name: notification x-group: Notifications - name: policy x-group: Policies - name: registry x-group: MCP Gateway - name: system-management x-group: Log Exports paths: /api/policy/v2/policies/{policy_id}/revisions/{revision_id}: get: tags: - policy summary: Get Policy Revision description: Return a single policy revision by ID, scoped to the given policy. operationId: get_policy_revision parameters: - name: policy_id in: path required: true schema: type: string title: Policy Id - name: revision_id in: path required: true schema: type: string title: Revision Id responses: '200': description: Successful Response content: application/json: schema: $ref: '#/components/schemas/PolicyRevisionDetailResponse' '422': description: Validation Error content: application/json: schema: $ref: '#/components/schemas/HTTPValidationError' components: schemas: PolicyRevisionDetailResponse: properties: revision: $ref: '#/components/schemas/PolicyRevisionSummary' rule_titles: additionalProperties: type: string type: object title: Rule Titles type: object required: - revision title: PolicyRevisionDetailResponse HTTPValidationError: properties: detail: items: $ref: '#/components/schemas/ValidationError' type: array title: Detail type: object title: HTTPValidationError PolicyRevisionSummary: properties: id: type: string format: uuid title: Id policy_id: type: string format: uuid title: Policy Id changes: additionalProperties: true type: object title: Changes description: Changes made in this revision revised_at: type: string format: date-time title: Revised At revised_by: type: string title: Revised By revised_by_name: anyOf: - type: string - type: 'null' title: Revised By Name description: >- Display name for the revision author. For cascade rows (revised_by == CASCADE_SYSTEM_USER_ID), this carries the composed string e.g. 'System (on behalf of Alice)' when the upstream actor is known. triggered_by: anyOf: - type: string - type: 'null' title: Triggered By description: UUID of the upstream actor for cascade rows; NULL for direct edits. triggered_by_name: anyOf: - type: string - type: 'null' title: Triggered By Name description: Resolved display name for triggered_by (NULL if unknown or N/A). categories: items: type: string type: array title: Categories description: Category chips classified at write time. changes_summary: items: type: string type: array title: Changes Summary description: Human-readable change descriptions. resolved_refs: additionalProperties: $ref: '#/components/schemas/ResolvedRef' type: object title: Resolved Refs description: '{uuid: {name, type}} for whitelisted refs.' version_number: type: integer title: Version Number description: 1-indexed position in the policy's revision history. default: 0 type: object required: - id - policy_id - changes - revised_at - revised_by title: PolicyRevisionSummary description: Summary of a policy revision. ValidationError: properties: loc: items: anyOf: - type: string - type: integer type: array title: Location msg: type: string title: Message type: type: string title: Error Type input: title: Input ctx: type: object title: Context type: object required: - loc - msg - type title: ValidationError ResolvedRef: properties: name: type: string title: Name type: type: string enum: - mcp_server - application title: Type type: object required: - name - type title: ResolvedRef description: Aligns with design §4 — only two ref types are ever stored. securitySchemes: ApiKey: type: http scheme: bearer description: >- A Barndoor API key, sent as `Authorization: Bearer `. Keys are prefixed `bdai_` and are opaque — do not attempt to decode one. Interchangeable with an OAuth 2.0 access token. OAuth2: type: oauth2 x-issuer: https://auth.barndoor.ai/realms/barndoor description: >- An OAuth 2.0 access token from Barndoor's identity provider, sent as `Authorization: Bearer `. Public clients must use PKCE. Interchangeable with an API key. flows: authorizationCode: authorizationUrl: >- https://auth.barndoor.ai/realms/barndoor/protocol/openid-connect/auth tokenUrl: >- https://auth.barndoor.ai/realms/barndoor/protocol/openid-connect/token scopes: openid: Issue an OIDC ID token identifying the caller. profile: Read the caller's basic profile claims. email: Read the caller's email address. offline_access: Issue a refresh token. Optional — no operation requires it. clientCredentials: tokenUrl: >- https://auth.barndoor.ai/realms/barndoor/protocol/openid-connect/token scopes: openid: Issue an OIDC ID token identifying the caller. profile: Read the caller's basic profile claims. email: Read the caller's email address. offline_access: Issue a refresh token. Optional — no operation requires it. ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.