---
title: "Quantiles"
method: GET
path: "/internal/v1/spans/{project_id}/quantiles"
tags: ["Querying"]
---

# Quantiles

`GET /internal/v1/spans/{project_id}/quantiles`

Query duration percentiles (p50, p90, p99) and count/error rate over time. Use this to identify latency outliers, track performance degradation, or compare SLO compliance. Returns named timeseries: count, countPerMin, errorCount, errorCountPerMin, durationP50, durationP90, durationP99, durationMax. Supports WHERE filters (e.g. where service_name = 'myservice'), full-text search, system filtering (e.g. httpserver:all), and duration filtering. Use timeseries instead when you need custom aggregation queries with GROUP BY. Use list_span_groups instead when you need a single aggregated snapshot. Documentation: https://uptrace.dev/features/querying/spans

## Path parameters

- `project_id` integer, required

## Query parameters

- `time_start` string, date-time, required — RFC3339 timestamp.
- `time_end` string, date-time, required — RFC3339 timestamp.
- `query` string
- `where` string
- `search` string
- `search_attrs` string[]
- `system` string[]
- `duration_gte` integer
- `duration_lt` integer
- `limit` integer

## Response `200`

Quantile timeseries data.

- object
  - `timeseries` Timeseries[], required — Array of named timeseries. Names include: count, countPerMin, errorCount, errorCountPerMin, durationP50, durationP90, durationP99, durationMax.
    - `name` string, required — Metric name (e.g., countPerMin, errorCountPerMin, durationP50, durationP90, durationP99).
    - `value` number[], required — Array of metric values.
    - `time` number[], required — Array of timestamps as unix milliseconds.

## Other responses

- `400` — Invalid request
- `401` — Authentication required
- `403` — Insufficient permissions
- `500` — Internal server error

---

[API](https://skmtc.net/uptrace/apis/uptrace-json-api.md) · [All operations](https://skmtc.net/uptrace/apis/uptrace-json-api/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/uptrace/uptrace-json-api/revisions/550c8881ab9a/schema)