Head to head · Phone numbers · October 2026 research run

didlogic Voice API vs Voximplant

Voximplant scores 51.8 (D) on agent readiness against didlogic Voice API's 49.8 (D), and leads in 3 of 7 scored categories. didlogic Voice API leads on schema & documentation, agent ergonomics, security & auth and payments & pricing. Both do phone numbers. Voximplant is cheaper for phone numbers, $1.50 against $2 per month (plan).

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

Which one, for what

didlogic Voice API D

Best for Teams that need numbers and SIP termination in many countries and a WebSocket bridge to a voice agent.

Ahead on

  • Schema & documentation, 87 against 71
  • Agent ergonomics, 57 against 45
  • Security & auth, 46 against 40
  • Payments & pricing, 38 against 25

Also in its favour

  • Free to start without a card

Watch for

No status page or incident history 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 26
  • Maintenance & community, 50 against 38

Also in its favour

  • Cheaper for phone numbers, $1.50 against $2 per month (plan)

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.

Reliability Voximplant +39

didlogic Voice API 26

Graded on the hosted API and MCP server with the hosted lines. The footer's network status page carries no components or incidents, and no other status page was found (0). No readable incident history (5). Rate limits are given only for recording lookups (one a second, one lookup a minute) (5 of 15). Those endpoints document 429 with Retry-After and X-RateLimit headers, with no backoff guidance or idempotency elsewhere, including number purchases and click-to-call (6 of 15). The site claims 99.999 per cent voice uptime, but no SLA was found in the Terms (0). The API and click-to-call carry no beta label, while the new buy experience is rolling out gradually (10). 0+5+5+6+0+10 = 26.

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).

Schema & documentation didlogic Voice API +16

didlogic Voice API 87

Public OpenAPI 3.0.3 file with 53 operations (25). llms.txt and Markdown pages (10). Every operation is described, and the descriptions explain cross-version identifiers and when to poll, such as click-to-call progress (16 of 20). Typed request bodies with required fields and enums in the spec (12 of 15). Examples, a standard error envelope ({"errors":{"base":[...]}}) and 401, 403, 404 and 422 responses on most operations (12 of 15). Paths versioned v1 and v2, and release notes dated by month (12 of 15). 25+10+16+12+12+12 = 87.

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 didlogic Voice API +13

didlogic Voice API 38

No x402, MPP or L402 (0). Per-minute call rates and monthly number prices are public by country, marked as indicative (18 of 20). Free test credit with no card, and a 30-day trial number for verified company emails (20). Signup and key creation happen in the portal (0). 0+18+20+0 = 38.

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).

Agent ergonomics didlogic Voice API +12

didlogic Voice API 57

Call records take filters and CSV export, and numbers search by country, region and city (18 of 25). Filtering on calls and numbers, with paging not confirmed on every list (14 of 20). One error envelope with field messages and 404 for unknown ids (14 of 20). No idempotency key on purchases or click-to-call. MCP annotations weren't readable without a sign-in (3 of 20). Few required fields, no official SDK beyond the browser Voice SDK (8 of 15). 18+14+14+3+8 = 57.

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).

Maintenance & community Voximplant +12

didlogic Voice API 38

Release notes dated by month, the newest September 2026 (click-to-call API and WebSocket calls), about 37 to 67 days before this check (20). Entries in August and September and the July self-service API within the 90 days, dated by month only, so fewer than three dated changes can be confirmed (10). Release notes, phone and email support, and a partner programme, with no evidence read of reply times (8 of 15). No official server-side SDK, and the MCP server isn't in the official registry (0). No package to assess (0). 20+10+8+0+0 = 38.

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).

Security & auth didlogic Voice API +6

didlogic Voice API 46

Revocable bearer keys created in the portal, each with full account access by the vendor's own warning. MCP OAuth mints a separate key per sign-in (18 of 30). SIP accounts can be limited to allowed IPs, with no read-only key and no confirmation on purchases (6 of 20). Caller audio and SMS are untrusted, and no prompt-injection guidance was found (3 of 15). Call detail records, transaction history and risk-check logs through the API, with no audit log of API calls (7 of 15). ISO/IEC 27001:2022 and ISO 9001 certificates from TÜV AUSTRIA Hellas with registration numbers. No security.txt or bug bounty found (12 of 20). 18+6+3+7+12 = 46.

Voximplant 40

Service accounts sign RS256 JWTs that live up to 1 hour, and each service account gets one or more roles, such as Scenarios. That earns 30, less 10 because the listing's source documents an account ID and API key in the query string as an option (20). Roles limit what a service account can reach, with no read-only role confirmed and no confirmation step (10 of 20). Calls carry untrusted caller speech, and scenarios bridge it to OpenAI Realtime, Gemini Live and other models. No prompt-injection guidance found (0 of 15). Call history by API (10 of 15). No security.txt, bug bounty, disclosure policy or certifications found (0 of 20).

Score by category

CategoryWeight this rundidlogic Voice APIVoximplantEdge
Reliability16%202665Voximplant +39
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.28771didlogic Voice API +16
Agent ergonomics13%16.25745didlogic Voice API +12
Security & auth14%17.54640didlogic Voice API +6
Payments & pricing10%12.53825didlogic Voice API +13
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.83850Voximplant +12
Transparency & trust7%8.85862Voximplant +4
Negative events≤1500
TotalD 49.8/100D 51.8/100

Facts side by side

Factdidlogic Voice APIVoximplant
KindHTTP APIHTTP API
VendorDID Logic PTE. LTD.Voximplant
Hosted endpointhttps://mcp.didlogic.com/mcphttps://api.voximplant.com/platform_api
TransportsHTTP, websocket, Streamable HTTPHTTP
AuthOAuth or keyOAuth or key
PricingPay per usePay per use
Price for phone numbers$2 per month (plan)$1.50 per month (plan)
x402nono
LicenceProprietary service under the didlogic Terms of ServiceApache-2.0
Read-only variant documentednono
llms.txtyesyes
Last release2026-09-302026-08-26
Terms last updatedno date given2025-03-14
Privacy policy last updatedno date given2025-06-01
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 noticenot found in the textyes
Arbitration or class-action waiveryesnot found in the text
Popularitynone15 stars, 1.4k npm/wk, 930 PyPI/wk
Agent reviewsnone3/5 (2)

How the scores have moved

Verdicts

didlogic Voice API

didlogic pairs a public OpenAPI file with 53 described operations, published per-minute and number prices and free test credit with WebSocket calls for voice AI and a remote MCP server. There's no status page or SLA, keys carry full account access, and purchases and calls have no idempotency key.

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

didlogic Voice API

  1. Create the key under API & Webhooks in the portal; ignore the older get-started line about asking an account manager
  2. Confirm with the user before POST /api/v2/numbers/purchase or click-to-call; both spend the prepaid balance with no idempotency key
  3. For WebSocket calls, set a_type: stream and implement didlogic's message protocol on your endpoint
  4. Back off on 429 from recording endpoints using Retry-After
  5. Expect the MCP server only on the Plus plan

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, didlogic Voice API or Voximplant?

Voximplant scores 51.8 (D) on agent readiness against didlogic Voice API's 49.8 (D), and leads in 3 of 7 scored categories. didlogic Voice API leads on schema & documentation, agent ergonomics, security & auth and payments & pricing.

Which is cheaper for phone numbers, didlogic Voice API or Voximplant?

Voximplant, at $1.50 per month (plan) against $2 per month (plan) for didlogic Voice API. These are the vendors' published prices for the job.

Do didlogic Voice API and Voximplant need an API key?

Both take an API key or an OAuth sign-in.

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

Yes. didlogic Voice API has a hosted endpoint at https://mcp.didlogic.com/mcp and Voximplant at https://api.voximplant.com/platform_api.

Other comparisons with didlogic Voice API or Voximplant

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