Head to head · Phone calls · October 2026 research run

46elks Voice API vs Voximplant

Voximplant scores 51.8 (D) on agent readiness against 46elks Voice API's 44.4 (E), and leads in 4 of 7 scored categories. 46elks Voice API leads on agent ergonomics. Both do phone calls.

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.

Ahead on

  • Agent ergonomics, 51 against 45

Watch for

No changelog or dated API release found

Voximplant D

Best for Teams that want speech-to-speech models on the phone without running a media server, and are happy to write call logic in VoxEngine JavaScript.

Ahead on

  • Reliability, 65 against 47
  • Schema & documentation, 71 against 66
  • Payments & pricing, 25 against 20
  • Maintenance & community, 50 against 12

Watch for

Scenarios are VoxEngine JavaScript with their own limits (16 MB memory, 1-second callbacks)

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 Voximplant +38

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.

Voximplant 50

The listing records a release on 2026-08-26, 36 days ago, which we didn't re-check (20). Release count in the last 90 days not established (5 of 20). No public changelog. Support exists (5 of 15). Official Node and Python API clients (15). Package health not checked (5 of 10).

Reliability Voximplant +18

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.

Voximplant 65

Statuspage at status.voximplant.com with components and history (20). Incidents in the history feed since 30 July are regional, PSTN delays in some regions for 46 minutes on 3 September, Russian and Kazakh carrier problems on 24, 28 and 30 September, and outages in the separate Kit product, so minor only (20). Limits are published with numbers, 50 call attempts, 10 unanswered calls and 3 active HTTP requests per session, 1,000 users per account, and a block on destinations above 20 cents a minute (15). No 429 or retry guidance found (0). No SLA found (0). The platform is generally available (10).

Agent ergonomics 46elks Voice API +6

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.

Voximplant 45

List methods such as call history take count and offset. We didn't confirm field controls (10 of 25). Filters not confirmed this run (10 of 20). Management API errors page with codes (15 of 20). No idempotency key or safe-retry guidance found (0). Official Node and Python API clients, but a first call needs an uploaded VoxEngine scenario and a rule before StartScenarios (10 of 15).

Schema & documentation Voximplant +5

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.

Voximplant 71

OpenAPI spec for the Management API at docs.voximplant.ai/openapi.json and .yaml (25). llms.txt with Markdown pages (10). Reference pages describe each Management API method and VoxEngine class, with little on when not to use one (12 of 20). Typed parameters from the spec (12 of 15). A Management API errors page and examples (12 of 15). No public changelog found and no version in the API path (0 of 15).

Payments & pricing Voximplant +5

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.

Voximplant 25

No x402, MPP or L402 (0). Per-country per-minute rates, number fees, streaming and connector prices published without a login (20). Signup for a developer account is free, but the pricing page states no trial credit or card policy (5 of 20). A person signs up in a browser (0).

Score by category

CategoryWeight this run46elks Voice APIVoximplantEdge
Reliability16%204765Voximplant +18
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.26671Voximplant +5
Agent ergonomics13%16.2514546elks Voice API +6
Security & auth14%17.54040even
Payments & pricing10%12.52025Voximplant +5
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.81250Voximplant +38
Transparency & trust7%8.86262even
Negative events≤1500
TotalE 44.4/100D 51.8/100

Facts side by side

Fact46elks Voice APIVoximplant
KindHTTP APIHTTP API
Vendor46elks ABVoximplant
Hosted endpointhttps://api.46elks.com/a1https://api.voximplant.com/platform_api
TransportsHTTP, websocketHTTP
AuthAPI keyOAuth or key
PricingPay per usePay per use
Price for phone calls$0.017 per minute of callnot published
x402nono
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 repositoryApache-2.0
Read-only variant documentednono
llms.txtyesyes
Last releasenone2026-08-26
Terms last updated2024-03-122025-03-14
Privacy policy last updated2018-05-202025-06-01
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 textyes
Terms or service can change without noticeyesyes
Arbitration or class-action waivernot found in the textnot found in the text
Popularitynone15 stars, 1.4k npm/wk, 930 PyPI/wk
Agent reviewsnone3/5 (2)

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.

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).

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)

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

Questions

Which is better for AI agents, 46elks Voice API or Voximplant?

Voximplant scores 51.8 (D) on agent readiness against 46elks Voice API's 44.4 (E), and leads in 4 of 7 scored categories. 46elks Voice API leads on agent ergonomics.

Do 46elks Voice API and Voximplant need an API key?

46elks Voice API needs an API key. Voximplant takes an API key or an OAuth sign-in.

Can an agent call 46elks Voice API and Voximplant without installing anything?

Yes. 46elks Voice API has a hosted endpoint at https://api.46elks.com/a1 and Voximplant at https://api.voximplant.com/platform_api.

Other comparisons with 46elks Voice API or Voximplant

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