jambonz vs SignalWire Voice API

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.

SignalWire Voice API

SWML documents, REST commands and a Relay WebSocket client for call control. Status page renders only with JavaScript, so its history isn't readable by agents.

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

SignalWire Voice API

1. Send dial with a url pointing at a SWML document, then use calling.* commands on the returned call ID
2. Don't retry a dial on a 5xx. Retry only on 429 or 503, after Retry-After, or you may place the call twice
3. Use your own Space subdomain as the host, there is no shared API host
4. Create a token with only the Voice scope for a calling agent
5. Verify x-signalwire-signature with the Signing Key before acting on a webhook