Get Cohort Stats

GET

sessions

:id

cohort-stats

curl https://api.promptster.ai/v1/sessions/sess_abc123/cohort-stats \
  -H "Authorization: Bearer psk_live_abc123def456"

{
  "cohortStats": {
    "sessionCount": 5,
    "metrics": {
      "avgDurationMs": 3600000,
      "avgPromptCount": 15.2,
      "avgCommandFailRate": 0.082,
      "avgVerifyIntensity": 2.1,
      "avgManualEditRatio": 0.28,
      "avgFirstChangeLatencyMs": 95000,
      "testPassRate": 60
    },
    "percentiles": {
      "durationMs": 0.75,
      "promptCount": 0.5,
      "commandFailRate": 0.25,
      "verifyIntensity": 0.75,
      "manualEditRatio": 0.5,
      "firstChangeLatencyMs": 0.75
    }
  }
}

Returns aggregate metrics across all completed sessions for the same assessment, plus percentile ranks showing how this candidate compares to the cohort. Requires at least 2 completed sessions for percentile computation.

Authentication

Requires either an org API key or a candidate key.

Authorization: Bearer psk_live_...

string

required

The session ID.

object | null

Cohort statistics, or null if no completed sessions exist for this assessment.

Show properties

integer

Number of completed sessions in the cohort.

object

Aggregate metrics across the cohort.

Show properties

number | null

Average session duration in milliseconds.

number

Average number of prompts per session.

number

Average command failure rate (0-1).

number

Average verification intensity score.

number

Average ratio of manual vs AI edits.

number | null

Average time to first code change in milliseconds.

integer

Percentage of candidates who passed all tests (0-100).

object

Percentile ranks for this candidate (0.0 = bottom, 1.0 = top). Only present when cohort has 2+ sessions.

Show properties

number | null

Duration percentile.

number | null

Prompt count percentile.

number | null

Command fail rate percentile (higher = fewer failures).

number | null

Verification intensity percentile.

number | null

Manual edit ratio percentile.

number | null

First change latency percentile.

{
  "cohortStats": {
    "sessionCount": 5,
    "metrics": {
      "avgDurationMs": 3600000,
      "avgPromptCount": 15.2,
      "avgCommandFailRate": 0.082,
      "avgVerifyIntensity": 2.1,
      "avgManualEditRatio": 0.28,
      "avgFirstChangeLatencyMs": 95000,
      "testPassRate": 60
    },
    "percentiles": {
      "durationMs": 0.75,
      "promptCount": 0.5,
      "commandFailRate": 0.25,
      "verifyIntensity": 0.75,
      "manualEditRatio": 0.5,
      "firstChangeLatencyMs": 0.75
    }
  }
}

curl https://api.promptster.ai/v1/sessions/sess_abc123/cohort-stats \
  -H "Authorization: Bearer psk_live_abc123def456"

curl https://api.promptster.ai/v1/sessions/sess_abc123/cohort-stats \
  -H "Authorization: Bearer psk_live_abc123def456"

{
  "cohortStats": {
    "sessionCount": 5,
    "metrics": {
      "avgDurationMs": 3600000,
      "avgPromptCount": 15.2,
      "avgCommandFailRate": 0.082,
      "avgVerifyIntensity": 2.1,
      "avgManualEditRatio": 0.28,
      "avgFirstChangeLatencyMs": 95000,
      "testPassRate": 60
    },
    "percentiles": {
      "durationMs": 0.75,
      "promptCount": 0.5,
      "commandFailRate": 0.25,
      "verifyIntensity": 0.75,
      "manualEditRatio": 0.5,
      "firstChangeLatencyMs": 0.75
    }
  }
}

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