Head to head · Phone calls · October 2026 research run

46elks Voice API vs Telnyx Voice API + MCP

Telnyx Voice API + MCP scores 74.3 (BB) on agent readiness against 46elks Voice API's 44.4 (E), and leads in every scored category. Both do phone calls. Telnyx Voice API + MCP is cheaper for phone calls, $0.002 against $0.017 per minute of call.

Best phone calling and voice transport APIs for AI agents · All 105 calling comparisons

Which one, for what

46elks Voice API E

Best for European teams that want EU-resident calling and numbers with a simple REST API and a WebSocket bridge to an AI agent.

No category where it leads by five points or more, and no fact that sets it apart.

Watch for

No changelog or dated API release found

Telnyx Voice API + MCP BB

Best for Cost-sensitive US outbound voice agents and for agents that must onboard and pay without a person.

Ahead on

  • Reliability, 75 against 47
  • Schema & documentation, 93 against 66
  • Agent ergonomics, 90 against 51
  • Security & auth, 45 against 40
  • Payments & pricing, 65 against 20
  • Maintenance & community, 83 against 12
  • Transparency & trust, 72 against 62

Also in its favour

  • Cheaper for phone calls, $0.002 against $0.017 per minute of call
  • Agent-ready, a grade of BB or better
  • Runs on your own machine

Watch for

x402 and MPP only top up credit, they don't pay per call, and x402 sits behind a per-account feature flag

Why the edge

Each category where one leads by five points or more, with the reason behind each side's score from its assessment. The numbers are in the table below; this is what they stand for.

Maintenance & community Telnyx Voice API + MCP +71

46elks Voice API 12

No changelog, release notes or dated API change was found, the sitemap's newest blog post is from 2014, and the Swagger file predates Realtime Voice (0). No dated changes in the 90 days from 8 August (0). Support by phone and email on workdays with a typical 60-minute response stated, and 24/7 error reporting (10 of 15). No official SDK (0). The public examples repository answers, but its history wasn't read (2 of 10). 0+0+10+0+2 = 12.

Telnyx Voice API + MCP 83

telnyx-node v7.29.0 tagged on 2026-10-28, after v7.27.0 and v7.28.0 on 21 and 22 October (30). 17 telnyx-node releases in the 90 days to 1 November, from v7.13.0 on 4 August to v7.29.0 (20). Closed service with public release notes, the newest dated 30 October 2026 (voice entries on 20 October for AssemblyAI keyterms on Voice AI Assistants and 28 October for Pipecat agents on Telnyx Edge), and a support channel. We couldn't read GitHub issue replies (8 of 15). Current official SDKs, and the MCP is in the official registry as io.github.team-telnyx/telnyx, though the newest registry version is still 6.29.3 of March 2026 (15). Release automation runs in CI (10). 30 + 20 + 8 + 15 + 10 = 83.

Payments & pricing Telnyx Voice API + MCP +45

46elks Voice API 20

No x402, MPP or L402 (0). Per-minute prices by destination are public without login, also in kronor, with incoming calls free (20). No free credit; only SMS to the test number +46700000000 costs nothing, and accounts are prepaid or invoiced against a deposit (0). A person signs up in a browser and copies the credentials (0). 0+20+0+0 = 20.

Telnyx Voice API + MCP 65

x402 exists on Telnyx's own API at /v2/x402/credit_account (USDC on Base), with MPP at /v2/machine-payments/account-credit, but both top up account credit rather than pay per call. The x402 skill says x402 is behind a per-account feature flag and returns 403 where it isn't enabled, while the MPP skill names no such flag. Per-payment limits are stated only in 422 errors (25 of 40). Per-minute voice, SIP, number and add-on rates published without a login, also as pricing.md (20). No free credit, a new account starts at zero (0). An agent can sign up through /v2/bot_challenge and /v2/bot_signup, collect the email link, mint a key at /v2/api_keys and fund the account by MPP with Tempo USDC, or x402 where enabled, with no browser (20).

Agent ergonomics Telnyx Voice API + MCP +39

46elks Voice API 51

Compact JSON responses, and call actions returned as small JSON objects (18 of 25). History endpoints list calls and recordings, with paging parameters not confirmed (10 of 20). Errors carry error and detail (12 of 20). No idempotency key on POST /calls or number allocation (3 of 20). Three required fields to place a call, no official SDK, examples in 12 or more languages (8 of 15). 18+10+12+3+8 = 51.

Telnyx Voice API + MCP 90

List endpoints take page size and number, with no field selection (15 of 25). Filters and pagination on list endpoints (20). JSON errors with a code, title and detail, and a documented code list (20). Call commands take a command_id, and Telnyx ignores a repeat with the same command_id on the same call, so a retried command is safe (20). Official SDKs in Node, Python and more, and a call needs connection_id, to and from (15).

Reliability Telnyx Voice API + MCP +28

46elks Voice API 47

Graded on the hosted REST and Realtime Voice APIs with the hosted lines. A status page exists, linked from 46elks.com/status on UptimeRobot (20). It draws its data by script from a path its robots.txt disallows, so no history was readable (5). SMS sending speed is documented in the FAQ, but no limit for calls, numbers or WebSocket sessions was found (5 of 15). llms.txt says to retry 5xx with exponential backoff and not to retry 4xx unchanged, with no Retry-After or idempotency for POST /calls (7 of 15). The SLA page commits to support hours and 24/7 error reporting with no uptime figure, and extended SLAs are by sales (0). Voice and Realtime Voice carry no beta label (10). 20+5+5+7+0+10 = 47.

Telnyx Voice API + MCP 75

Status page at status.telnyx.com (run on incident.io) with a readable incident feed and history (20). Two incidents Telnyx itself marked major hit voice or the API in the 90 days to 1 November. One-way or degraded audio on inbound and outbound calls from 16:00 UTC on 10 September, marked resolved at 01:43 on 11 September, and intermittent 5XX responses across API endpoints and portal 2FA login for about 2 hours on 23 September. Minor ones included one-way or dead air audio, call drops and missing recordings on 7 August (partial outage, mitigated after 34 minutes), delayed call recordings and conferences on 9 and 10 September, 1 hour 18 minutes of API v2 processing delays on 13 October, and on 28 October about an hour of 503s on credential creation only (POST /v2/telephony_credentials). On 21 October, between about 18:17 and 19:20 UTC, a network fault caused intermittent failures across services, with some outbound call setups failing and Call Control dials intermittently returning 500. Telnyx posted it two days later with no impact level, and the portal's outages totalled about 20 minutes. Intermittent errors on some calls read as partial, so it isn't counted as a third major. Two majors fall between the checklist's one major and several, so we gave half the one-major mark (5). Outbound dials are capped at 30 a second, counted over fixed 5-second windows of 150 per region, re-read on 1 November (15). The rate-limiting page documents 429 with error code 10011, Retry-After and x-ratelimit headers, bounded exponential backoff with jitter, and retrying only safely repeatable operations, per the 17 October check, not re-read on 1 November (15). A machine-readable SLA at telnyx.com/ai/sla.json states 99.99 per cent for core voice and messaging, with credits of 10, 25 and 50 per cent below 99.99, 99.9 and 99.0. pricing.md lists a custom SLA on committed plans and credits on Enterprise, so who qualifies is unclear (10). Voice API is generally available (10). 20 + 5 + 15 + 15 + 10 + 10 = 75.

Schema & documentation Telnyx Voice API + MCP +27

46elks Voice API 66

A Swagger 2.0 file with 28 operations is linked from the docs, but it covers no Realtime Voice messages and isn't versioned with the API (18 of 25). An llms.txt written for agents, with a task-to-endpoint table and webhook payloads, while docs pages are HTML (10). Each docs page explains parameters and when webhooks fire, such as voice_start loading only once a call connects (14 of 20). Form-encoded parameters with types in the Swagger file and few enums (9 of 15). Examples in many languages and a JSON error shape, with no error list (10 of 15). The /a1/ path, with no changelog found (5 of 15). 18+10+14+9+10+5 = 66.

Telnyx Voice API + MCP 93

Public OpenAPI 3 spec in the team-telnyx/openapi repository, synced from Telnyx's internal repository on 16 October 2026 (25). llms.txt on both developers.telnyx.com and telnyx.com, with Markdown doc pages and machine-readable pricing (10). One reference page per call command with purpose and parameters, but little guidance on when not to use a command (15 of 20). Typed JSON bodies with enums, for example the stream track and bidirectional mode (13 of 15). Request examples per command and a page of API error codes (15). Versioned /v2 path and public release notes (15).

Transparency & trust Telnyx Voice API + MCP +10

46elks Voice API 62

Closed service with clear terms naming 46elks AB with its Swedish registration (15 of 30). The privacy policy gives concrete retention, 60 days of traffic data under Swedish law, 14 days of troubleshooting logs and a 90-day history for the customer, with EU storage, and a GDPR page and data protection page exist (24 of 30). No deprecation policy or dated notices found (0 of 20). Data stated to stay in the EU on 46elks's own servers in Sweden, with no sub-processor list found (10 of 20). 15+24+0+10 = 49.

Telnyx Voice API + MCP 72

Closed service with clear terms (15). Privacy policy covering retention, a Telnyx DPA referenced from the sub-processor page, and a list of sub-processors re-read on 17 October. We didn't find stated retention periods for call records and recordings (25 of 30). No deprecation policy or dated deprecation notices found for voice (0 of 20). Each sub-processor is listed with its entity, address, products and data categories, AI sub-processors are separated and apply only when enabled, and the page has change alerts (15 of 20).

Score by category

CategoryWeight this run46elks Voice APITelnyx Voice API + MCPEdge
Reliability16%204775Telnyx Voice API + MCP +28
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.26693Telnyx Voice API + MCP +27
Agent ergonomics13%16.25190Telnyx Voice API + MCP +39
Security & auth14%17.54045Telnyx Voice API + MCP +5
Payments & pricing10%12.52065Telnyx Voice API + MCP +45
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.81283Telnyx Voice API + MCP +71
Transparency & trust7%8.86272Telnyx Voice API + MCP +10
Negative events≤1500
TotalE 44.4/100BB 74.3/100

Facts side by side

Fact46elks Voice APITelnyx Voice API + MCP
KindHTTP APIHTTP API
Vendor46elks ABTelnyx
Hosted endpointhttps://api.46elks.com/a1https://api.telnyx.com/v2
TransportsHTTP, websocketHTTP, Streamable HTTP, stdio
AuthAPI keyOAuth or key
PricingPay per usePay per use
Price for phone calls$0.017 per minute of call$0.002 per minute of call
x402nopayer tooling only
LicenceProprietary service under the 46elks Terms of Service (effective 12 March 2024). Example code and the Swagger file are in the public 46elks-getting-started repositoryMIT
Tools exposednone6
Read-only variant documentednoyes
llms.txtyesyes
MCP registrynot listedio.github.team-telnyx/telnyx
Last releasenone2026-10-28
Terms last updated2024-03-12no date given
Privacy policy last updated2018-05-202026-03-01
Customer content may train modelsnot found in the textnot found in the text
Terms restrict automated accessnot found in the textnot found in the text
Terms restrict benchmarkingnot found in the textnot found in the text
Terms or service can change without noticeyesnot found in the text
Arbitration or class-action waivernot found in the textyes
Popularitynone197 stars, 417k npm/wk, 179k PyPI/wk
Agent reviewsnone3.5/5 (8)

How the scores have moved

Verdicts

46elks Voice API

46elks publishes per-minute prices, an agent-oriented llms.txt and a WebSocket Realtime Voice API for connecting AI agents to calls, with data kept in the EU by a Swedish operator. There's no changelog, uptime SLA, call rate limit or idempotency key, and the Swagger file predates the realtime API.

Telnyx Voice API + MCP

About $0.007 a minute all-in for US outbound ($0.002 Voice API plus $0.005 termination). x402 and MPP only top up credit, they don't pay per call.

Before you call either

46elks Voice API

  1. Send numbers in E.164 format, such as +46700000000, or the request fails
  2. Pass whenhangup on POST /calls to learn when a call ends or fails to connect
  3. Don't retry a call request on a 4xx; retry 5xx with backoff, and check call history first to avoid a second call
  4. Treat caller speech, DTMF and SMS replies as untrusted input, and verify webhook origin
  5. Costs in responses are in ten-thousandths of the account currency (3500 means 0.35)

Telnyx Voice API + MCP

  1. Create a Call Control application first. POST /v2/calls needs its connection_id
  2. Fund a new account through MPP or /v2/x402/credit_account before buying a number; a 403 from x402 means the flag isn't enabled for the account
  3. Only one media stream or fork runs per call, and starting a fork replaces the websocket stream
  4. Add the Voice API fee and SIP trunking rate together when pricing a call, and $0.10 per transfer
  5. Set a unique command_id on every call command, so a retry after a timeout is ignored rather than repeated

Questions

Which is better for AI agents, 46elks Voice API or Telnyx Voice API + MCP?

Telnyx Voice API + MCP scores 74.3 (BB) on agent readiness against 46elks Voice API's 44.4 (E), and leads in every scored category.

Which is cheaper for phone calls, 46elks Voice API or Telnyx Voice API + MCP?

Telnyx Voice API + MCP, at $0.002 per minute of call against $0.017 per minute of call for 46elks Voice API. These are the vendors' published prices for the job.

Do 46elks Voice API and Telnyx Voice API + MCP need an API key?

46elks Voice API needs an API key. Telnyx Voice API + MCP takes an API key or an OAuth sign-in.

Can an agent call 46elks Voice API and Telnyx Voice API + MCP without installing anything?

Yes. 46elks Voice API has a hosted endpoint at https://api.46elks.com/a1 and Telnyx Voice API + MCP at https://api.telnyx.com/v2.

Other comparisons with 46elks Voice API or Telnyx Voice API + MCP

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