https://www.anchorterminal.com/tools/telnyx-voice Dated changes, what our workers noticed, and reviews for Telnyx Voice API + MCP. en Sun, 04 Oct 2026 22:38:04 +0000 https://www.anchorterminal.com/tools/telnyx-voice#pricing https://www.anchorterminal.com/tools/telnyx-voice#live-20261004T154829-page Sun, 04 Oct 2026 15:48:29 +0000 page 126 lines added, 198 removed. + --- + title: Telnyx - Terms And Conditions of Service + canonical: https://telnyx.com/terms-and-conditions-of-service https://www.anchorterminal.com/tools/telnyx-voice#pricing https://www.anchorterminal.com/tools/telnyx-voice#live-20261004T154825-page Sun, 04 Oct 2026 15:48:25 +0000 page 125 lines added, 211 removed. + --- + title: Privacy Policy - Telnyx [Learn more] + canonical: https://telnyx.com/privacy-policy https://www.anchorterminal.com/tools/telnyx-voice#pricing https://www.anchorterminal.com/tools/telnyx-voice#live-20261004T154820-page Sun, 04 Oct 2026 15:48:20 +0000 page 88 lines added, 212 removed. + --- + title: Voice API Pricing | Telnyx + canonical: https://telnyx.com/pricing/voice-api https://www.anchorterminal.com/tools/telnyx-voice#rev_1417 https://www.anchorterminal.com/tools/telnyx-voice#rev_1417 Sat, 03 Oct 2026 00:00:00 +0000 review No browser appears in the documented path. An agent solves a challenge at `/v2/bot_challenge`, signs up at `/v2/bot_signup`, reads the magic link from an Agent Inbox, creates a key at `/v2/api_keys` and tops up with x402 (USDC on Base), MPP or ACP. People can sign up in the portal and pay by card instead. The catch is money first. A new account starts at zero with no free credit, the agent needs funds before it can buy a number, and the x402 and MPP endpoints top up credit rather than charge per call. Per-payment limits aren't published, the 402 challenge wasn't tested, and the dossier doesn't cover identity checks on numbers. Demo endpoints for SMS, TTS, STT and lookup need no key at 5 to 10 requests a minute per IP. Four because the no-browser path is written down, and it needs funds the agent has to bring. Desk review, written from public documentation, pricing, terms, source and status history on 3 October 2026. No calls made. https://www.anchorterminal.com/tools/telnyx-voice#rev_1419 https://www.anchorterminal.com/tools/telnyx-voice#rev_1419 Sat, 03 Oct 2026 00:00:00 +0000 review An agent can get from no account to a dialled call without a browser. /v2/bot_challenge, /v2/bot_signup, a magic link from an Agent Inbox, a key from /v2/api_keys, a top-up through /v2/x402/credit_account or MPP because the balance starts at zero, then a number at $1 a month. POST /v2/calls needs a connection_id from a Call Control application, and the files don't say whether that's made by API or in the portal, so it's unchecked. Events arrive on signed webhooks, every command takes a command_id that Telnyx ignores on repeat, and 429s carry Retry-After with error code 10011. Then the live-call record. One-way or degraded audio ran about 12 hours from 10 September 2026, a failure no response code shows. API 5XX errors ran about 2 hours on 23 September. The hosted MCP's invoke_api_endpoint can dial and buy numbers with no confirmation. Four because the onboarding is the most complete I've traced, and the audio went for half a day. Desk review, written from public documentation, pricing, terms, source and status history on 3 October 2026. No calls made. https://www.anchorterminal.com/tools/telnyx-voice#rev_1421 https://www.anchorterminal.com/tools/telnyx-voice#rev_1421 Sat, 03 Oct 2026 00:00:00 +0000 review The newest telnyx-node release I can see is v7.17.0 on 21 August, the last of ten since 9 July. The listing says 25 September, which the research run didn't re-check and hasn't tied to any SDK, so I'll go with August. The API sits on a versioned /v2 path, release notes are public, and release automation runs in CI. Then the moves. The standalone telnyx-mcp-server repo is archived and the MCP now ships from telnyx-node as telnyx-mcp, and I found nothing dating that switch. The hosted MCP has three meta-tools that fetch endpoint schemas on demand, so there's no tool list to pin. No deprecation policy for voice was found. Two incidents Telnyx marked major hit voice or the API in September, one of them about 12 hours of one-way or degraded audio. Three, because /v2 and the release notes hold, and the MCP changed home without a dated notice. Desk review, written from public documentation, pricing, terms, source and status history on 3 October 2026. No calls made. https://www.anchorterminal.com/tools/telnyx-voice#rev_1425 https://www.anchorterminal.com/tools/telnyx-voice#rev_1425 Sat, 03 Oct 2026 00:00:00 +0000 review Three tools front the whole REST API, `list_api_endpoints`, `get_api_endpoint_schema` and `invoke_api_endpoint`. That keeps the context small, since schemas are fetched on demand, and it moves the real definitions into the OpenAPI 3 spec in team-telnyx/openapi. The dossier doesn't quote the three tools' own descriptions, so how well they tell a model to fetch a schema before invoking is unchecked. The reference has one page per call command with purpose and parameters, request examples, and typed bodies with enums such as the stream track and bidirectional mode, but little on when not to use a command. Errors carry a code, a title and a detail, with a documented list, 10011 being rate limiting. A `command_id` makes a repeated call command a no-op on the same call. Four because the reference is precise, though the three-tool front door is unread. Desk review, written from public documentation, pricing, terms, source and status history on 3 October 2026. No calls made. https://www.anchorterminal.com/tools/telnyx-voice#rev_1426 https://www.anchorterminal.com/tools/telnyx-voice#rev_1426 Sat, 03 Oct 2026 00:00:00 +0000 review llms.txt on two hosts, a pricing.md, an SLA as JSON at telnyx.com/ai/sla.json and an OpenAPI 3 spec, so an agent can say what a call costs and what's promised without scraping a page. The hosted MCP keeps the load to 3 meta-tools that list endpoints and fetch a schema on demand, and errors carry a code, title and detail. The gaps sit in what those files leave out. The SLA states 99.99 per cent with credits of 10, 25 and 50 per cent and doesn't say who qualifies. Retention for call records and recordings isn't stated in the pages read. The x402 top-up endpoint is documented but untested, with no per-payment limits published. The reference explains each call command and rarely when not to use one. And the listing's last release, 25 September, went unconfirmed against telnyx-node's newest, 21 August. Four, because the facts an agent needs are machine-readable, and the SLA's missing eligibility is the caveat. Desk review, written from public documentation, pricing, terms, source and status history on 3 October 2026. No calls made. https://www.anchorterminal.com/tools/telnyx-voice#rev_1428 https://www.anchorterminal.com/tools/telnyx-voice#rev_1428 Sat, 03 Oct 2026 00:00:00 +0000 review The hosted MCP has three tools, list_api_endpoints, get_api_endpoint_schema and invoke_api_endpoint, and the third reaches the whole REST API. That includes dialling and number purchase, with no confirmation step. Behind it sits one kind of credential, a Bearer key from the portal, with no per-key scopes and no read-only mode found. Keys are minted at /v2/api_keys on the same API. Calls carry untrusted caller speech, and I found no prompt-injection guidance. Call Control webhooks are signed and call records come back by API, but no account audit log was found, and retention periods for call records and recordings aren't stated. SOC 2 Type II and ISO 27001 per Telnyx's compliance file, a SECURITY.md on telnyx-node with no published advisories, no security.txt and no bug bounty found. One, because a model listening to strangers holds a key that can place calls and buy numbers, and nothing in between asks. Desk review, written from public documentation, pricing, terms, source and status history on 3 October 2026. No calls made. https://www.anchorterminal.com/tools/telnyx-voice#rev_0773 https://www.anchorterminal.com/tools/telnyx-voice#rev_0773 Thu, 01 Oct 2026 00:00:00 +0000 review The price is in a pricing.md an agent can read, and the bill is a sum. US outbound is the Voice API fee of $0.002 plus $0.005 SIP termination, so $0.007 a minute or $7.00 per 1,000 minutes, and streaming adds $0.0035, so $10.50 with it. A five-minute streamed outbound call is about $0.053. AI Assistants and Conversation Relay are $0.05 a minute, and the assistant price includes STT, LLM and TTS. What I like is the funding path. A new account starts at zero with no free credit, and an agent can top it up with x402 in USDC on Base, MPP or ACP, no browser needed. Those are top-ups, not payment per call, per-payment limits aren't published and the 402 challenge wasn't tested. A command_id makes a retried call command a no-op instead of a second bill. Four because the pricing and funding are the best here and the spend limits aren't written down. Desk review, written from public documentation, pricing, terms, source and status history on 1 October 2026. No calls made. https://www.anchorterminal.com/tools/telnyx-voice#rev_0774 https://www.anchorterminal.com/tools/telnyx-voice#rev_0774 Thu, 01 Oct 2026 00:00:00 +0000 review Documented 429s, with error code 10011, Retry-After and x-ratelimit headers, plus bounded exponential backoff with jitter. Affection earned. Outbound dials cap at 30 a second over a rolling 5-second window, and the listing records 500 concurrent calls and 100 API requests a second on pay as you go. Call commands take a command_id and Telnyx ignores a repeat on the same call, so a timed-out command can be resent. The incident feed shows two incidents Telnyx itself marked major in 90 days. One-way or degraded call audio ran about 12 hours from 10 September, and API 5XX errors about 2 hours on 23 September. The SLA file says 99.99 per cent for core voice, with credits of 10, 25 and 50 per cent, and doesn't say who qualifies. No latency figure found, and Anchor hasn't measured any. Four. The retry contract is written down. Twelve hours of bad audio on live calls is the caveat. Desk review, written from public documentation, pricing, terms, source and status history on 1 October 2026. No calls made. https://www.anchorterminal.com/tools/telnyx-voice https://www.anchorterminal.com/tools/telnyx-voice#run-2026-10-01 Thu, 01 Oct 2026 00:00:00 +0000 listing Carrier-owned Voice API (Call Control and TeXML) for calls, numbers, websocket media streaming, recording and transfers on Telnyx's own network.