jambonz vs Voximplant

jambonz

OpenAPI 3.1 and AsyncAPI documents, an llms.txt and Markdown pages cover the REST and WebSocket APIs, and session prices are public. No status page, security.txt or advisory was found, API keys carry no scopes, and the 2021 privacy policy says audio is never stored while the October 2026 release notes say support keeps call audio for a few days.

Voximplant

Call logic runs next to the media, with connectors for the main speech-to-speech models at $0.004 a minute. Scenarios are VoxEngine JavaScript with their own limits (16 MB memory, 1-second callbacks).

jambonz

1. Send Authorization: Bearer <token> to https://api.jambonz.cloud/v1, the server in the OpenAPI files. The REST introduction page gives https://jambonz.cloud/api instead, so confirm the base URL with the operator
2. Create a call with from, to and either application_sid or call_hook. Do not retry a timed-out create without checking GET /Accounts/{AccountSid}/Calls first
3. Read ratelimit-remaining and ratelimit-reset on every response and stop when a 429 arrives
4. Append #rc=3&rp=5xx,ct to an application URL to turn on webhook retries. HTTP webhooks are not retried by default
5. Check the account has a carrier and speech credentials before dialling. jambonz does not supply numbers, minutes or speech services

Voximplant

1. Upload a VoxEngine scenario and a rule first, then start it with StartScenarios and pass the number in script_custom_data
2. Use a service-account JWT rather than api_key in the URL
3. Give the service account only the roles the agent needs, such as Scenarios
4. Ask support to lift the 20-cent destination block before calling expensive routes