Speko Docs
API Reference

TTS Models

Compare the TTS models your organization can route on measured naturalness, robustness, cost and first-audio latency, with the regional and per-language readings alongside.

GET
/v1/tts/models

Authorization

bearerAuth
AuthorizationBearer <token>

In: header

Query Parameters

language?string

Which language cell to report. Robustness is measured for English only.

Default"en"
use_case?string

Narrow to models with at least one voice meeting this use case. Rows included only by include_unroutable=true are not narrowed, since no voice evidence exists for a model this organization cannot route.

Value in"longform" | "phone"
sort?string
Default"natural"
Value in"natural" | "latency" | "cost" | "robustness"
order?string

Defaults to ascending for latency and cost, descending for the other axes.

Value in"asc" | "desc"
include_unroutable?string
Default"false"
Value in"true" | "false" | "1" | "0"

Response Body

application/json

application/json

{
  "object": "string",
  "language": "string",
  "sort": "string",
  "order": "string",
  "data": [
    {
      "id": "cartesia:sonic-3.5",
      "provider": "string",
      "model": "string",
      "routable": true,
      "routable_via": "platform_key",
      "benchmark": {
        "language": "string",
        "board": "string",
        "naturalness": {
          "value": 0,
          "unit": "string",
          "higher_is_better": true,
          "board": "string",
          "ci": [
            0
          ],
          "n": 0,
          "basis": "string",
          "unjudgeable": 0,
          "field_mean": 0,
          "comparable_across_languages": true,
          "estimated": true
        },
        "robustness": {
          "value": 0,
          "unit": "string",
          "higher_is_better": true,
          "board": "string",
          "ci": [
            0
          ],
          "n": 0,
          "basis": "string",
          "unjudgeable": 0,
          "field_mean": 0,
          "comparable_across_languages": true,
          "estimated": true
        },
        "panel_mos": {
          "value": 0,
          "unit": "string",
          "higher_is_better": true,
          "board": "string",
          "ci": [
            0
          ],
          "n": 0,
          "basis": "string",
          "unjudgeable": 0,
          "field_mean": 0,
          "comparable_across_languages": true,
          "estimated": true
        },
        "panel_named_pct": {
          "value": 0,
          "unit": "string",
          "higher_is_better": true,
          "board": "string",
          "ci": [
            0
          ],
          "n": 0,
          "basis": "string",
          "unjudgeable": 0,
          "field_mean": 0,
          "comparable_across_languages": true,
          "estimated": true
        },
        "latency_ms": 0,
        "latency_evidence": {
          "board": "string",
          "region": "string",
          "n": 0,
          "p90_ms": 0
        },
        "latency": {
          "vendor_direct": [
            {
              "region": "string",
              "location": "string",
              "p50_ms": 0,
              "p90_ms": 0
            }
          ],
          "per_language": [
            {
              "language": "string",
              "p50": 0,
              "p90": 0,
              "n": 0,
              "sweeps": 0,
              "wide_tail": true,
              "voice": "string"
            }
          ]
        },
        "cost": {
          "per_1m_chars_usd": 0,
          "per_min_usd": 0,
          "higher_is_better": true
        }
      },
      "languages": {
        "measured": [
          "string"
        ],
        "vendor_claimed": [
          "string"
        ],
        "count": 0
      },
      "voices": {
        "total": 0,
        "measured": 0,
        "compatibility": "verified"
      }
    }
  ],
  "meta": {
    "benchmark": {
      "schema": 0,
      "routing_policy_version": "string"
    },
    "quality_overlay": {
      "generated_at": "string",
      "run_id": "string"
    },
    "org_routable_vendors": [
      "string"
    ],
    "coverage": {
      "models_routable": 0,
      "models_measured": 0,
      "voices_routable": 0,
      "voices_measured": 0
    },
    "notes": [
      "string"
    ]
  }
}
Empty
{
  "error": "Unauthorized",
  "code": "UNAUTHORIZED"
}

Voices

Read-only catalog of TTS voices grouped by provider. ElevenLabs voices are account-scoped and fetched live from ElevenLabs rather than returned here.

TTS Voices

Browse voices by measured quality (no hiss, steady to the end, repeatable, characters per call) and get the provider, model and voice ids to synthesize with.