---
title: "Metric and label names"
description: "The metric and label names endpoints of the HTTP API."
---

> Documentation Index
> Fetch the complete documentation index at: https://slashobserve.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Metric and label names

## GET /datasources/{uid}/metrics

List the metric names of a datasource, up to a limit.

The browser's only path to metric names; it never calls a datasource directly. It runs the same code, validation and limits as the agent's `list_metrics` tool: a Prometheus datasource lists its metrics with their type and help, and a ClickHouse datasource lists the OpenTelemetry metric names of its `otel_metrics_*` tables with the OTel kind as `type` and the table. The call takes one of the server's shared upstream slots, waiting at most 5 seconds for one before it answers 429 `too_many_requests` with `Retry-After`, counts against the per-caller in-flight limit, times out after 15 seconds and is never cached. Any query parameter not listed below, or one given twice, is a 400.

### Parameters

| Name | In | Type | Description |
| --- | --- | --- | --- |
| `uid` (required) | path | `string` |   |
| `search` | query | `string` | Case-insensitive substring filter. |
| `limit` | query | `integer` | Maximum names to return. Between 1 and 500. Default `100`. |

### Responses

| Status | Description | Body |
| --- | --- | --- |
| `200` | Up to `limit` metrics; `truncated` is true when there were more. | `object` |
| `400` | The request is malformed or fails validation. | [`Error`](/docs/reference/api/schemas/#error) |
| `401` | Authentication is missing or invalid. | [`Error`](/docs/reference/api/schemas/#error) |
| `404` | The resource does not exist. | [`Error`](/docs/reference/api/schemas/#error) |
| `422` | The query or its variables cannot run, or its result exceeds a limit. | [`Error`](/docs/reference/api/schemas/#error) |
| `429` | The caller already has the maximum number of query requests in flight, or the server's shared upstream call slots stayed busy for 5 seconds. | [`Error`](/docs/reference/api/schemas/#error) |
| `500` | The server failed to handle the request. | [`Error`](/docs/reference/api/schemas/#error) |
| `502` | The datasource is unavailable. | [`Error`](/docs/reference/api/schemas/#error) |
| `504` | The datasource did not answer within the query timeout. | [`Error`](/docs/reference/api/schemas/#error) |

## GET /datasources/{uid}/labels

List the label names of a datasource, or its OpenTelemetry attribute keys on ClickHouse, up to a limit.

The browser's only path to label names; it never calls a datasource directly. It runs the same code, validation and limits as the agent's `list_labels` tool. ClickHouse labels need `table` or `metric`: with only `metric` the server uses the first `otel_metrics_*` table that holds it, and answers 404 `not_found` when none does. A ClickHouse request with neither is a 400. The call takes one of the server's shared upstream slots, waiting at most 5 seconds for one before it answers 429 `too_many_requests` with `Retry-After`, counts against the per-caller in-flight limit, times out after 15 seconds and is never cached. Any query parameter not listed below, or one given twice, is a 400.

### Parameters

| Name | In | Type | Description |
| --- | --- | --- | --- |
| `uid` (required) | path | `string` |   |
| `metric` | query | `string` | Only names seen on this metric. On ClickHouse it also finds the metric's table when `table` is not given. |
| `table` | query | `string` | ClickHouse table such as `otel_logs`; Prometheus ignores it. |
| `search` | query | `string` | Case-insensitive substring filter. |
| `limit` | query | `integer` | Maximum names to return. Between 1 and 500. Default `100`. |

### Responses

| Status | Description | Body |
| --- | --- | --- |
| `200` | Up to `limit` label names; `truncated` is true when there were more. | `object` |
| `400` | The request is malformed or fails validation. | [`Error`](/docs/reference/api/schemas/#error) |
| `401` | Authentication is missing or invalid. | [`Error`](/docs/reference/api/schemas/#error) |
| `404` | The resource does not exist. | [`Error`](/docs/reference/api/schemas/#error) |
| `422` | The query or its variables cannot run, or its result exceeds a limit. | [`Error`](/docs/reference/api/schemas/#error) |
| `429` | The caller already has the maximum number of query requests in flight, or the server's shared upstream call slots stayed busy for 5 seconds. | [`Error`](/docs/reference/api/schemas/#error) |
| `500` | The server failed to handle the request. | [`Error`](/docs/reference/api/schemas/#error) |
| `502` | The datasource is unavailable. | [`Error`](/docs/reference/api/schemas/#error) |
| `504` | The datasource did not answer within the query timeout. | [`Error`](/docs/reference/api/schemas/#error) |

## GET /datasources/{uid}/labels/{name}/values

List the values of one label of a datasource, up to a limit.

The browser's only path to label values; it never calls a datasource directly. It runs the same code, validation and limits as the agent's `list_label_values` tool. ClickHouse labels need `table` or `metric`, as for the label names operation, and a malformed label name is a 422 `query_invalid`. The call takes one of the server's shared upstream slots, waiting at most 5 seconds for one before it answers 429 `too_many_requests` with `Retry-After`, counts against the per-caller in-flight limit, times out after 15 seconds and is never cached. Any query parameter not listed below, or one given twice, is a 400.

### Parameters

| Name | In | Type | Description |
| --- | --- | --- | --- |
| `uid` (required) | path | `string` |   |
| `name` (required) | path | `string` |   |
| `metric` | query | `string` | Only names seen on this metric. On ClickHouse it also finds the metric's table when `table` is not given. |
| `table` | query | `string` | ClickHouse table such as `otel_logs`; Prometheus ignores it. |
| `search` | query | `string` | Case-insensitive substring filter. |
| `limit` | query | `integer` | Maximum names to return. Between 1 and 500. Default `100`. |

### Responses

| Status | Description | Body |
| --- | --- | --- |
| `200` | Up to `limit` values of the label; `truncated` is true when there were more. | `object` |
| `400` | The request is malformed or fails validation. | [`Error`](/docs/reference/api/schemas/#error) |
| `401` | Authentication is missing or invalid. | [`Error`](/docs/reference/api/schemas/#error) |
| `404` | The resource does not exist. | [`Error`](/docs/reference/api/schemas/#error) |
| `422` | The query or its variables cannot run, or its result exceeds a limit. | [`Error`](/docs/reference/api/schemas/#error) |
| `429` | The caller already has the maximum number of query requests in flight, or the server's shared upstream call slots stayed busy for 5 seconds. | [`Error`](/docs/reference/api/schemas/#error) |
| `500` | The server failed to handle the request. | [`Error`](/docs/reference/api/schemas/#error) |
| `502` | The datasource is unavailable. | [`Error`](/docs/reference/api/schemas/#error) |
| `504` | The datasource did not answer within the query timeout. | [`Error`](/docs/reference/api/schemas/#error) |

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