---
title: "List deterministic signals available to evaluators"
method: GET
path: "/v1/evals/signals"
tags: ["evals", "evals"]
---

# List deterministic signals available to evaluators

`GET /v1/evals/signals`

Closed catalog of signals a deterministic evaluator can be bound to.

Drives the frontend's signal-picker UI when creating an evaluator with
``kind='deterministic'``. Sourced from the in-process probe registry —
no DB hit.

## Response `200`

Successful Response

- SignalCatalogResponse — Closed set of deterministic signals available to evaluators.
  - `signals` SignalCatalogItem[], required
    - `key` string, required
    - `label` string, required
    - `unit` string, required
    - `format` 'boolean' | 'enum' | 'numeric' | 'score', required
    - `aggregations` string[], required
    - `filters` SignalFilterDimResponse[]
      - `key` string, required
      - `type` 'string' | 'string_list' | 'string_to_string_map', required
      - `required` boolean
      - `description` string
    - `channels` string[], required
    - `description` string

## Other responses

- `400` — Bad request
- `401` — Authentication required

---

[API](https://skmtc.net/oneloop-hq/apis/feather-api.md) · [All operations](https://skmtc.net/oneloop-hq/apis/feather-api/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/oneloop-hq/feather-api/versions/888bdd5c076e/schema)