API reference

Base URL: https://api.mistral.ai/v1/observability, with Authorization: Bearer $MISTRAL_API_KEY. Access is controlled by your workspace role; see Before you start.

Scorers

Method	Path	Notes
`POST`	`/scorers`	Create. Returns 201 with the generated `slug`.
`GET`	`/scorers`	List. `q` filters on slug, name, or description. Paginated (`page`, `page_size`).
`GET`	`/scorers/{scorer_slug}`	Includes `latest_version` (`version`, `config`, `variables`).
`PATCH`	`/scorers/{scorer_slug}`	Any of `name`, `description`, `config`. A changed `config` creates a new version.

There is no delete. Body fields are described in Scorers.

Live evals (pipelines)

Method	Path	Notes
`POST`	`/pipelines`	Create. Returns 201 with `pipeline_configs[]`.
`GET`	`/pipelines`	List. `q` filters on name, `enabled` filters. Paginated (`page`, `page_size`).
`GET`	`/pipelines/{pipeline_id}`
`PUT`	`/pipelines/{pipeline_id}`	Partial: send only the fields to change. Explicit `null` is rejected, except for `description`.
`DELETE`	`/pipelines/{pipeline_id}`	204. Hard delete.

Body fields and update semantics are described in Live evals.

The response for a live eval:

{
  "id": "018f1a2b-…",
  "slug": "support-answers-1c2d3e4f",
  "name": "Support answers",
  "description": "…",
  "enabled": true,
  "selectors": [{ "source_kind": "span", "filter": "…" }],
  "pipeline_configs": [
    {
      "slug": "helpfulness-1a2b3c4d-7b04d1aa",
      "scorer_slug": "helpfulness-1a2b3c4d",
      "scorer_version": 3,
      "pipeline_kind": "judge-v1",
      "sampling": { "type": "probabilistic", "percentage": 20 },
      "definition": { "model": "…", "prompt": "…", "result_spec": { "…": "…" }, "mapping": { "…": "…" }, "use_cache": true },
      "…": "…"
    }
  ],
  "creator_id": "…",
  "created_at": "…",
  "updated_at": "…"
}

{
  "id": "018f1a2b-…",
  "slug": "support-answers-1c2d3e4f",
  "name": "Support answers",
  "description": "…",
  "enabled": true,
  "selectors": [{ "source_kind": "span", "filter": "…" }],
  "pipeline_configs": [
    {
      "slug": "helpfulness-1a2b3c4d-7b04d1aa",
      "scorer_slug": "helpfulness-1a2b3c4d",
      "scorer_version": 3,
      "pipeline_kind": "judge-v1",
      "sampling": { "type": "probabilistic", "percentage": 20 },
      "definition": { "model": "…", "prompt": "…", "result_spec": { "…": "…" }, "mapping": { "…": "…" }, "use_cache": true },
      "…": "…"
    }
  ],
  "creator_id": "…",
  "created_at": "…",
  "updated_at": "…"
}

Results

All results routes require a workspace role with access to observability traffic and take from and to as query parameters (default: the last hour, maximum: 750 hours).

Method	Path	Body	Pagination
`POST`	`/spans/evaluations/search`	`search_expression`	`page_size`, `cursor`
`POST`	`/spans/evaluations/search/latest`	`search_expression`	`page_size`, `cursor`
`POST`	`/pipeline-results/search`	`pipeline_config_slugs` (1–100), `search_expression`	`page_size`, `cursor`
`POST`	`/spans/evaluations/aggregate`	`metric`, `dimensions`, `time_dimension`, `search_expression`, `order_by`, `limit`	—
`GET`	`/spans/evaluations/fields`	—	—
`GET`	`/spans/evaluations/fields/{field_name}/options`	—	—

Response shapes are described in Reading results.

Errors

Status	When
400	Invalid `search_expression` (syntax error or unknown field) or invalid Jinja2 template.
403	Access denied: your role lacks the permission, your organization isn't on the Enterprise tier or disabled observability, or you used a service account key to create a live eval. Ask your workspace administrator to check your role.
404	Unknown scorer slug or pipeline id in this workspace.
409	A live eval with the same name exists in the workspace, or a generated slug collided. Rename the live eval, or retry.
422	Validation: bad filter syntax, a mapping key that is not a scorer variable, `source_kind` other than `span`, a scorer name starting with a digit, a time window over the maximum, or `from` after `to`.