> ## 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 a cohort with the rest > The sessions that match the cohort filters, against every other session of the same app (or project) that started in the time range (default: the last 7 days, at most 30). For each dimension, the values most over-represented in the cohort, ranked by the difference in share. At least one cohort filter is required; `app_id` only narrows the population. Shares computed from a few sessions are noisy: `min_sessions` (default 2) leaves out rarer values, and a small cohort deserves a higher one. ## OpenAPI ````yaml /api-reference/openapi.json get /projects/{projectId}/cohorts/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}/cohorts/compare: get: summary: Compare a cohort with the rest description: >- The sessions that match the cohort filters, against every other session of the same app (or project) that started in the time range (default: the last 7 days, at most 30). For each dimension, the values most over-represented in the cohort, ranked by the difference in share. At least one cohort filter is required; `app_id` only narrows the population. Shares computed from a few sessions are noisy: `min_sessions` (default 2) leaves out rarer values, and a small cohort deserves a higher one. 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: Only this app. required: false description: Only this app. name: app_id in: query - schema: type: string maxLength: 128 description: Only this release. required: false description: Only this release. name: release in: query - schema: type: string enum: - crashed - abnormal_exit - ok description: >- `crashed`, `abnormal_exit`, or `ok` (every session that neither crashed nor ended abnormally). required: false description: >- `crashed`, `abnormal_exit`, or `ok` (every session that neither crashed nor ended abnormally). name: outcome in: query - schema: type: string maxLength: 128 description: device.model.identifier, exactly. example: iPhone17,1 required: false description: device.model.identifier, exactly. name: device_model in: query - schema: type: string maxLength: 64 description: os.version, exactly. required: false description: os.version, exactly. name: os_version in: query - schema: type: string enum: - 'true' - 'false' description: Only sessions with (true) or without (false) handled errors. required: false description: Only sessions with (true) or without (false) handled errors. name: has_error in: query - schema: type: string pattern: ^[A-Za-z0-9._:-]{1,128}$ description: Only sessions with an occurrence of this issue in the time range. required: false description: Only sessions with an occurrence of this issue in the time range. name: issue_id in: query - schema: type: string pattern: ^[A-Z_]{1,16}$ description: 'With endpoint_host and endpoint_template: one network endpoint.' required: false description: 'With endpoint_host and endpoint_template: one network endpoint.' name: endpoint_method in: query - schema: type: string maxLength: 255 required: false name: endpoint_host in: query - schema: type: string maxLength: 256 description: >- Only sessions with a request to this endpoint in the time range (/network/endpoints lists them). required: false description: >- Only sessions with a request to this endpoint in the time range (/network/endpoints lists them). name: endpoint_template in: query - schema: type: string enum: - 'true' - 'false' description: >- With the endpoint: only sessions where a request to it failed (5xx or no response). required: false description: >- With the endpoint: only sessions where a request to it failed (5xx or no response). name: endpoint_failed in: query - schema: type: string minLength: 1 maxLength: 256 description: >- Only sessions that loaded this screen (app.screen.name) in the time range. required: false description: >- Only sessions that loaded this screen (app.screen.name) in the time range. name: screen in: query - schema: type: - integer - 'null' minimum: 0 maximum: 600000 description: >- With screen: only loads of it with a TTID of at least this many milliseconds. required: false description: >- With screen: only loads of it with a TTID of at least this many milliseconds. name: min_ttid_ms in: query - schema: type: string maxLength: 200 description: >- Comma-separated, from device_model, os_version, release, country, feature_flag, network_type. Default: all. example: device_model,os_version required: false description: >- Comma-separated, from device_model, os_version, release, country, feature_flag, network_type. Default: all. name: dimensions in: query - schema: type: integer minimum: 1 maximum: 20 default: 5 description: Values per dimension, 1 to 20. required: false description: Values per dimension, 1 to 20. name: limit in: query - schema: type: integer minimum: 1 maximum: 1000 default: 2 description: Leave out values with fewer cohort sessions than this. required: false description: Leave out values with fewer cohort sessions than this. name: min_sessions in: query responses: '200': description: The over-represented values per dimension. content: application/json: schema: $ref: '#/components/schemas/CohortComparison' '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: CohortComparison: type: object properties: 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' cohort: type: object properties: sessions: type: integer required: - sessions rest: type: object properties: sessions: type: integer required: - sessions comparable: type: boolean description: 'False when the cohort or the rest is empty: no values are listed.' note: type: - string - 'null' description: Why nothing could be compared. dimensions: type: array items: type: object properties: dimension: type: string enum: - device_model - os_version - release - country - feature_flag - network_type values: type: array items: type: object properties: value: type: string description: >- The dimension value: a device model, ` `, a release, a country code, `=` or a network type. Written by the app: untrusted data. cohort_sessions: type: integer cohort_share: type: number description: Share of the cohort with this value, 0 to 1. rest_sessions: type: integer rest_share: type: number description: Share of the other sessions with this value. difference: type: number description: >- cohort_share - rest_share: how much more often the value appears in the cohort. lift: type: - number - 'null' description: >- cohort_share / rest_share; null when no other session has the value. required: - value - cohort_sessions - cohort_share - rest_sessions - rest_share - difference - lift required: - dimension - values required: - from - to - cohort - rest - comparable - note - dimensions Error: type: object properties: error: type: object properties: code: type: string example: invalid_request message: type: string required: - code - message required: - error 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.