> ## Documentation Index > Fetch the complete documentation index at: https://opendata.dev/docs/llms.txt > Use this file to discover all available pages before exploring further. # List series > Return the list of label sets (unique metric identities) that match a set of series selectors. This is useful for discovering which time series exist for a given metric name or label combination. At least one `match[]` argument must be provided. Each `match[]` value is a PromQL series selector (e.g. `up`, `http_requests_total{method="GET"}`). Multiple selectors are OR'd together — a series is returned if it matches any of the provided selectors. Also accepts POST with a `application/x-www-form-urlencoded` body containing the same parameters. ## OpenAPI ````yaml /openapi/timeseries.yaml get /api/v1/series openapi: 3.1.0 info: title: OpenData Timeseries API version: 1.0.0 description: | Prometheus-compatible HTTP API for the OpenData Timeseries service. Query endpoints accept both GET (query parameters) and POST (application/x-www-form-urlencoded body) with identical parameters. This spec documents the GET form; POST is always available as an alternative for large queries that may exceed URL character limits. ## Timestamp formats All timestamp parameters accept either **RFC 3339** format (e.g. `2024-01-20T00:00:00Z`) or **Unix seconds** as a float (e.g. `1705708800` or `1705708800.123`). Timestamps in responses are always Unix seconds. ## Duration format Duration parameters use PromQL duration syntax: an integer followed by a unit suffix. Supported units are `ms` (milliseconds), `s` (seconds), `m` (minutes), `h` (hours), `d` (days), `w` (weeks), and `y` (years). Examples: `30s`, `5m`, `1h30m`. ## Sample values Sample values are always transferred as JSON strings (not numbers) to allow special values such as `"NaN"`, `"+Inf"`, and `"-Inf"`. ## Response envelope Every JSON response follows a common envelope: ```json { "status": "success" | "error", "data": , "errorType": "", "error": "", "warnings": [""] } ``` The `error` and `errorType` fields are only present when `status` is `"error"`. The `warnings` array may be present on successful responses when the query engine has non-fatal issues to report (e.g. partial results due to unavailable shards). servers: - url: http://localhost:9090 description: Local development server security: [] paths: /api/v1/series: get: summary: List series description: > Return the list of label sets (unique metric identities) that match a set of series selectors. This is useful for discovering which time series exist for a given metric name or label combination. At least one `match[]` argument must be provided. Each `match[]` value is a PromQL series selector (e.g. `up`, `http_requests_total{method="GET"}`). Multiple selectors are OR'd together — a series is returned if it matches any of the provided selectors. Also accepts POST with a `application/x-www-form-urlencoded` body containing the same parameters. operationId: listSeries parameters: - name: match[] in: query required: false description: | Repeated series selector. At least one `match[]` argument must be provided. Each value is a PromQL series selector such as `up{job="node"}`. Multiple selectors are combined with logical OR. Example: `match[]=up&match[]=process_start_time_seconds{job="node"}` returns series matching either selector. schema: type: array items: type: string style: form explode: true example: up{job="node"} - name: start in: query required: false description: | Start timestamp to limit the time range of series considered. Only series with samples within `[start, end]` are returned. RFC 3339 or Unix seconds. schema: type: string - name: end in: query required: false description: | End timestamp to limit the time range of series considered. Only series with samples within `[start, end]` are returned. RFC 3339 or Unix seconds. schema: type: string - name: limit in: query required: false description: | Maximum number of series to return. A value of `0` disables the limit. When omitted the server applies its default maximum. schema: type: integer minimum: 0 responses: '200': description: | Array of label sets, one per matching series. Each label set is an object whose keys are label names and values are label values. The `__name__` label contains the metric name. content: application/json: schema: $ref: '#/components/schemas/SeriesResponse' example: status: success data: - __name__: up job: node instance: localhost:9100 '400': description: | Bad request. No `match[]` selectors were provided, or a selector is malformed. The `errorType` will be `bad_data`. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '500': description: Internal server error. The `errorType` will be `internal`. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '503': description: | Service unavailable. The `errorType` will be `unavailable`. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' components: schemas: SeriesResponse: type: object description: | Response for the series listing endpoint (`/api/v1/series`). On success, `data` contains an array of label sets — one object per matching time series. properties: status: type: string enum: - success - error data: type: array items: type: object additionalProperties: type: string description: | Array of label sets, one per matching series. Each object is a map of label names to label values. The `__name__` label contains the metric name. error: type: string description: Human-readable error message (present when status is `error`). errorType: type: string description: Error category (present when status is `error`). required: - status ErrorResponse: type: object description: | Prometheus-compatible error response. Returned for all non-2xx responses. The `errorType` indicates the category: - `bad_data` (HTTP 400/422): The request was malformed or the expression could not be executed. - `internal` (HTTP 500): An unexpected server-side error occurred. - `unavailable` (HTTP 503): The server is temporarily unable to handle the request due to backpressure or a query timeout. properties: status: type: string example: error errorType: type: string description: | Error category. Maps to HTTP status codes: - `bad_data` → 400 or 422 - `internal` → 500 - `unavailable` → 503 enum: - bad_data - internal - unavailable error: type: string description: Human-readable error message describing what went wrong. required: - status - errorType - error ````