Kotoba API Reference
This API reference explains how to use Kotoba Technologies' REST API and Realtime API.
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Authentication
To use the API, sign up in the dashboard and create an API key.
Keep your API key secret. Never ship it in client-side code (browser/mobile). Use it only in a secure server environment.
You can immediately revoke your API key (or schedule it to expire) from the dashboard. Use the newly issued replacement key.
Use HTTP Bearer auth:
curl https://api.kotobatech.ai/v1/realtime/transcription_sessions \
-H "Authorization: Bearer $KOTOBA_API_KEY"
We also accept HTTP Basic auth with the API key as the username (empty password):
curl -u $KOTOBA_API_KEY: https://api.kotobatech.ai/v1/realtime/transcription_sessions
Rate limits
We apply rate limits per API key to protect system stability. If you are rate-limited, you’ll receive HTTP 429 with an Error JSON.
Realtime connections have separate concurrency limits. See Realtime ASR (Speech-to-Text) API.
As a rough guide, REST endpoints are limited to around 30 requests/sec per API key. The internal calculation and exact limits may change over time, and we may not be able to disclose detailed thresholds.
Request / response format
For POST, send a JSON body (Content-Type: application/json). For GET/DELETE, use query parameters. Responses are UTF-8 JSON.
Timestamps are generally returned as UNIX epoch seconds.
OpenAPI spec / mocking
We publish the OpenAPI spec at /openapi.yaml. For non-realtime REST APIs, you can run a local mock server using tools like Prism.