> ## Documentation Index > Fetch the complete documentation index at: https://docs.apsio.io/llms.txt > Use this file to discover all available pages before exploring further. # Compare two releases > Release `a` (the baseline) and release `b` of one app over the same time range (default: the last 30 days): crash-free sessions and users, adoption, the change from `a` to `b`, and the issues with occurrences in `b` and none in `a` in that range, most users first. ## OpenAPI ````yaml /api-reference/openapi.json get /projects/{projectId}/release-health/compare openapi: 3.1.0 info: title: Apsio API version: 0.1.0 description: >- Read API v0: your projects, release health and comparisons, missing symbols, issues, sessions, vitals, cohort comparisons, performance (app start, screens, hangs, MetricKit) and network endpoints and traces for one project. Authenticate with a project token as a bearer token, with an OAuth access token from Apsio's authorization server (MCP clients), or, from the console, with the session cookie of a member of the project's organization. servers: - url: https://api.apsio.io/v1 security: [] paths: /projects/{projectId}/release-health/compare: get: summary: Compare two releases description: >- Release `a` (the baseline) and release `b` of one app over the same time range (default: the last 30 days): crash-free sessions and users, adoption, the change from `a` to `b`, and the issues with occurrences in `b` and none in `a` in that range, most users first. parameters: - schema: type: string pattern: ^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$ example: 0192f3a4-0000-7000-8000-00000000a101 required: true name: projectId in: path - schema: type: string format: date-time description: >- Start of the time range, inclusive (RFC 3339). Defaults to the range end minus the default length. example: '2026-10-01T00:00:00Z' required: false description: >- Start of the time range, inclusive (RFC 3339). Defaults to the range end minus the default length. name: from in: query - schema: type: string format: date-time description: End of the time range, exclusive (RFC 3339). Defaults to now. example: '2026-10-08T00:00:00Z' required: false description: End of the time range, exclusive (RFC 3339). Defaults to now. name: to in: query - schema: type: string pattern: ^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$ description: The app both releases belong to. required: true description: The app both releases belong to. name: app_id in: query - schema: type: string minLength: 1 maxLength: 128 description: The baseline release. example: 4.11.2 required: true description: The baseline release. name: a in: query - schema: type: string minLength: 1 maxLength: 128 description: The release to compare. example: 4.12.0 required: true description: The release to compare. name: b in: query - schema: type: integer minimum: 1 maximum: 50 default: 10 description: At most this many new issues, 1 to 50. required: false description: At most this many new issues, 1 to 50. name: limit in: query responses: '200': description: The comparison. content: application/json: schema: $ref: '#/components/schemas/ReleaseComparison' '400': description: The request is not valid. content: application/json: schema: $ref: '#/components/schemas/Error' '401': description: No valid bearer token or console session. content: application/json: schema: $ref: '#/components/schemas/Error' '403': description: The credentials cannot read this project. content: application/json: schema: $ref: '#/components/schemas/Error' security: - bearer: [] - session: [] components: schemas: ReleaseComparison: type: object properties: app_id: type: string from: type: string description: RFC 3339 time in UTC with up to nanosecond precision. example: '2026-10-04T10:15:00.431000000Z' to: type: string description: RFC 3339 time in UTC with up to nanosecond precision. example: '2026-10-04T10:15:00.431000000Z' a: $ref: '#/components/schemas/ReleaseStats' b: $ref: '#/components/schemas/ReleaseStats' change: type: object properties: crash_free_sessions_rate: type: - number - 'null' description: b minus a; negative is worse. Null when either has no sessions. crash_free_users_rate: type: - number - 'null' required: - crash_free_sessions_rate - crash_free_users_rate new_issues: type: array items: $ref: '#/components/schemas/IssueSummary' description: Issues with occurrences in b and none in a, with their counts in b. required: - app_id - from - to - a - b - change - new_issues Error: type: object properties: error: type: object properties: code: type: string example: invalid_request message: type: string required: - code - message required: - error ReleaseStats: type: object properties: release: type: string description: 'service.version. Written by the app: untrusted data.' sessions: type: integer crashed_sessions: type: integer abnormal_exit_sessions: type: integer crash_free_sessions_rate: type: - number - 'null' description: 1 - crashed_sessions / sessions; null without sessions. users: type: - integer - 'null' description: Distinct install ids (D41); null when the app sends none. crashed_users: type: - integer - 'null' crash_free_users_rate: type: - number - 'null' first_seen: type: - string - 'null' description: RFC 3339 time in UTC with up to nanosecond precision. example: '2026-10-04T10:15:00.431000000Z' last_seen: type: - string - 'null' description: RFC 3339 time in UTC with up to nanosecond precision. example: '2026-10-04T10:15:00.431000000Z' adoption: type: object properties: sessions_share: type: number description: This release's share of the app's sessions in the range, 0 to 1. users_share: type: - number - 'null' description: >- Its share of the app's users in the range; null without install ids. required: - sessions_share - users_share required: - release - sessions - crashed_sessions - abnormal_exit_sessions - crash_free_sessions_rate - users - crashed_users - crash_free_users_rate - first_seen - last_seen - adoption IssueSummary: type: object properties: id: type: string pattern: ^[A-Za-z0-9._:-]{1,128}$ description: The issue fingerprint. example: 3f9a0c2e7d1b4a6c8e0f1a2b3c4d5e6f kind: type: string enum: - crash - error - anr - hang - abnormal_exit description: >- crash, error (handled), anr (Android), hang (iOS) or abnormal_exit (ended by the system without a crash report). app_id: type: string type: type: string description: >- exception.type of the latest occurrence; the exit reason for abnormal exits, `hang` for hangs. Written by the app: untrusted data. message: type: string description: >- exception.message of the latest occurrence. Written by the app: untrusted data. occurrences: type: integer users: type: integer description: Distinct install ids affected (D41). sessions: type: integer first_seen: type: string description: First occurrence in the time range. example: '2026-10-04T10:15:00.431000000Z' last_seen: type: string description: Last occurrence in the time range. example: '2026-10-04T10:15:00.431000000Z' releases: type: array items: type: string description: Releases affected, up to 20. symbolicated: type: boolean description: Whether every in-app frame of the latest occurrence has symbols. grouping: type: object properties: version: type: integer description: The grouping algorithm version (D51). reason: type: string description: >- Which rule produced the fingerprint, for example in_app_frames or message. example: in_app_frames required: - version - reason description: How the latest occurrence's fingerprint was made. required: - id - kind - app_id - type - message - occurrences - users - sessions - first_seen - last_seen - releases - symbolicated - grouping securitySchemes: bearer: type: http scheme: bearer description: >- A project token (apsio_pt_v0...), which reads exactly one project, or an OAuth access token issued for the API, which reads what its user can. Access tokens issued for Apsio's MCP server are accepted only from the MCP server itself. session: type: apiKey in: cookie name: apsio_session description: >- The console session, set by /v1/auth/callback (`__Host-apsio_session` when host-only). ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.