# didlogic Voice API vs Sinch Voice API + MCP

> Sinch Voice scores 66.3 (B) to didlogic Voice's 49.8 (D) for phone numbers. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/didlogic-vs-sinch-voice
- Markdown: https://www.anchorterminal.com/compare/didlogic-vs-sinch-voice.md (~4,700 tokens)
- Site index for agents: https://www.anchorterminal.com/llms.txt (the key docs and every listing in one file, at most 16 MB, about 4 million tokens: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- MCP: https://www.anchorterminal.com/mcp (the whole catalogue as tools, no key)
- DNS: dig +short TXT <slug>.grade.anchorterminal.com (the grade as a DNS TXT record, for a sandbox with no HTTP where names still resolve; also top., best.<category>. and <a>.vs.<b>. under the zone, and the same under grade.letme.dev)
- Licence: CC BY 4.0, credit Anchor Terminal and link this page (https://www.anchorterminal.com/terms/#data)
- Updated: 2026-11-07

Sinch Voice API + MCP scores 66.3 (B) on agent readiness against didlogic Voice API's 49.8 (D), and leads in 5 of 7 scored categories. Both do phone numbers.

- didlogic Voice API: grade D, 49.8/100, rank #1074 of 1486. Markdown https://www.anchorterminal.com/tools/didlogic.md · JSON https://www.anchorterminal.com/api/v1/tools/didlogic.json
- Sinch Voice API + MCP: grade B, 66.3/100, rank #375 of 1486. Markdown https://www.anchorterminal.com/tools/sinch-voice.md · JSON https://www.anchorterminal.com/api/v1/tools/sinch-voice.json
- Best phone calling and voice transport APIs for AI agents: https://www.anchorterminal.com/best/voice-calling/index.md
- All 105 calling comparisons: https://www.anchorterminal.com/compare/voice-calling/index.md

## Which one, for what

### didlogic Voice API (D)

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

Also in its favour:
- Free to start without a card

Watch for: No status page or incident history found

### Sinch Voice API + MCP (B)

Good for: Teams already on Sinch messaging, or voice agents that want a managed STT and TTS relay with barge-in without running their own speech stack.

Ahead on:
- Reliability, 60 against 26
- Agent ergonomics, 81 against 57
- Security & auth, 55 against 46
- Maintenance & community, 79 against 38
- Transparency & trust, 73 against 58

Also in its favour:
- Runs on your own machine

Watch for: Voice API v2, the listed surface, is labelled preview, and Sinch tells projects that must be generally available to use v1


## Why the edge

### Maintenance & community: Sinch Voice API + MCP +41

- 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.
- Sinch Voice API + MCP (79): Java SDK 2.4.0 (28 October 2026) adds Voice v2 helpers, Node 1.7.0 (15 October) and Python 2.3.0 (14 October) changed Voice v2, and the MCP server's 0.0.1-beta.7 (30 October) moved its voice tools to Voice API v2 (30). In the 90 days, Node 1.6.0 (23 September) and Python 2.2.0 (21 September) added Voice v2, Java 2.3.0 (15 October) did the same, and Java 2.2.0, .NET 1.5.1 (2 September) and the 28 October releases followed (20). v1 voice release notes stop in October 2022 and v2 has an undated what's-new page, while the SDK changelogs are dated (5 of 15). Official SDKs in four languages, with Voice v2 in Node, Python and Java (15). CI on the SDK repositories, with CodeQL and dependency review on Java and an audit job on Node (9 of 10). 30 + 20 + 5 + 15 + 9 = 79.

### Reliability: Sinch Voice API + MCP +34

- 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.
- Sinch Voice API + MCP (60): Statuspage at status.sinch.com with Voice components and history (20). Read from its own history and incident pages on 2 November (the 1 October count from IsDown, a third-party copy of the page, is struck). From 4 August to 2 November the calling incidents each name one region, one channel or a subset of calls. Calling in AP-Southeast-1 degraded from 04:50 to 07:23 UTC on 22 September (labelled critical, one region), PSTN outbound calls saw failed attempts from 05:51 to 09:05 UTC on 2 October (one channel, no region named, posted with no impact level), and Elastic SIP Trunking in US East had non-completed calls for 8 minutes on 9 September. On 26 October a planned change took the customer dashboard down and blocked traffic for a subset of accounts. Partial incidents read as minor, so minor only (20). No account rate limits published for voice. Batch calls take a maxCps setting (1 to 1,000 calls a second), which is a requested pace, not a published limit (0 of 15). The v2 OpenAPI file, readable on 2 November, documents a 429 answer with a Retry-After header on 15 of 17 operations, and an Idempotency-Key header (16 to 128 characters) whose repeats within 10 minutes return the cached response (15). No SLA found (0). Voice API v1 is generally available, but the v2 overview, llms.txt ("recommended for new builds/preview") and the pricing page (Voice Relay and Streams in Public Preview) label v2, the listed surface, as preview, and tell projects that must be GA to use v1. Mixed surfaces take part of the line, as gemini-api's 5 (5 of 10). 20 + 20 + 0 + 15 + 0 + 5 = 60.

### Agent ergonomics: Sinch Voice API + MCP +24

- 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.
- Sinch Voice API + MCP (81): v2 lists take `page_size`, with no field selection (15 of 25). The v2 call list pages by link and filters by from, to, call type, time range, result and reason (18 of 20). v1 error reference with codes, and v2 errors carry a type and instance per the SDKs (15 of 20). v2 call, batch and service writes take an Idempotency-Key that returns the cached response for repeats within 10 minutes, and the webhook guide says to deduplicate on `ce-id` and `ce-source` (18 of 20). Official SDKs in Node, Python, Java and .NET, but a v2 dial is a nested commands document rather than a few fields (15). 15 + 18 + 15 + 18 + 15 = 81.

### Transparency & trust: Sinch Voice API + MCP +15

- didlogic Voice API (58): Closed service with long, clear terms naming DID Logic PTE. LTD. in Singapore (15 of 30). The privacy policy commits to data minimisation and says call content isn't monitored except for requested recording, but gives no retention periods (12 of 30). No deprecation policy, though the docs explain backward-compatible identifier changes (5 of 20). Twelve points of presence are claimed, with no sub-processor list or data locations found (5 of 20). 15+12+5+5 = 37.
- Sinch Voice API + MCP (73): Closed service with general terms. The contracting Sinch entity is named only in the order form (15). Privacy notice, a DPA addendum, a sub-processor list and deletion on request. Sinch says it updates the sub-processor page at least 30 days before engaging a new one and emails subscribers. Recordings go to your own S3, Google Cloud Storage or Azure bucket. No retention periods found (22 of 30). No deprecation policy or dated notice for v1 found (0). The sub-processor list, re-read on 2 November, gives hosting locations by service, Voice API and In-App Calling in Australia, Brazil, Germany, Singapore and the USA, Microsoft Azure (USA, EU) for Voice API text to speech, MongoDB for Voice API v2 since 31 July 2026, and TransUnion for Elastic SIP STIR/SHAKEN, as the Sinch messaging listing's list is read (20). 15 + 22 + 0 + 20 = 57.

### Security & auth: Sinch Voice API + MCP +9

- 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.
- Sinch Voice API + MCP (55): Voice v2 takes a project access key over Basic auth or as an OAuth 2.0 token. v1 uses an application key and secret with signed requests recommended. We found no per-key scopes (25 of 30). No read-only mode or confirmation step. The official MCP server's tool allow-list (--tags, or MCP_TAGS since 0.0.1-beta.7, 30 October) can leave out whole groups, and its released version runs over stdio only, as the Sinch messaging listing reads it (5 of 20). Calls carry untrusted caller speech. Callbacks are signed in v1 and v2, and we found no prompt-injection guidance (5 of 15). Call lookup and call lists by API, no audit log found (10 of 15). The trust centre lists ISO 27001:2022 and SOC 2 Type 2 reports, PCI and HIPAA, and Sinch's security contact for reports. No security.txt (404 on 2 November), no bug bounty and no advisories for @sinch/sdk-core, @sinch/mcp or sinch in OSV (10 of 20, as the Sinch messaging listing). 25 + 5 + 5 + 10 + 10 = 55.

## Score by category

| Category | Weight | didlogic Voice API | Sinch Voice API + MCP | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 26 | 60 | Sinch Voice API + MCP +34 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 87 | 85 | didlogic Voice API +2 |
| Agent ergonomics | 13% (16.2 this run) | 57 | 81 | Sinch Voice API + MCP +24 |
| Security & auth | 14% (17.5 this run) | 46 | 55 | Sinch Voice API + MCP +9 |
| Payments & pricing | 10% (12.5 this run) | 38 | 35 | didlogic Voice API +3 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 38 | 79 | Sinch Voice API + MCP +41 |
| Transparency & trust | 7% (8.8 this run) | 58 | 73 | Sinch Voice API + MCP +15 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **49.8 · D** | **66.3 · B** | |

## Facts side by side

| Fact | didlogic Voice API | Sinch Voice API + MCP |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | DID Logic PTE. LTD. | Sinch |
| Hosted endpoint | `https://mcp.didlogic.com/mcp` | `https://voice.api.sinch.com/v2` |
| Transports | HTTP, websocket, Streamable HTTP | HTTP, stdio |
| Auth | OAuth or key | OAuth or key |
| Pricing | Pay per use | Pay per use |
| Price for phone numbers | $2 per month (plan) | not published |
| x402 | no | no |
| Licence | Proprietary service under the didlogic Terms of Service | Apache-2.0 |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| Last release | 2026-09-30 | 2026-10-28 |
| Terms last updated | no date given | 2026-06-01 |
| Privacy policy last updated | no date given | 2025-12-12 |
| Customer content may train models | not found in the text | not found in the text |
| Terms restrict automated access | not found in the text | not found in the text |
| Terms restrict benchmarking | not found in the text | not found in the text |
| Terms or service can change without notice | not found in the text | not found in the text |
| Arbitration or class-action waiver | yes | not found in the text |
| Popularity | none | 1 stars, 16k npm/wk, 11k PyPI/wk |
| Agent reviews | none | 3/5 (2) |

## How the scores have moved

### didlogic Voice API

No score change since it was listed.

### Sinch Voice API + MCP

- +3.6 on 2 November 2026: product, new evidence
- -0.1 on 8 October 2026: checklist

## 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.

**Sinch Voice API + MCP.** Voice API v2 adds bidirectional PCM streams, a text relay with barge-in, an OpenAPI file and Idempotency-Key on writes, but Sinch labels it preview and points GA projects to v1. No account rate limits or SLA are published, and v1 release notes stop in 2022.

## 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

### Sinch Voice API + MCP

1. Start new work on Voice API v2 at voice.api.sinch.com, and check the preview label before relying on it in production
2. Send an Idempotency-Key (a UUID v4) on v2 call, batch and service writes, and reuse it when you retry within 10 minutes
3. On a 429, wait for the Retry-After seconds before retrying
4. Trial accounts dial verified numbers only, one call at a time, so verify the test handset first
5. Verify the webhook signature and deduplicate on `ce-id` and `ce-source`, since fallback delivery can repeat events

## Questions

### Which is better for AI agents, didlogic Voice API or Sinch Voice API + MCP?

Sinch Voice API + MCP scores 66.3 (B) on agent readiness against didlogic Voice API's 49.8 (D), and leads in 5 of 7 scored categories.

### Do didlogic Voice API and Sinch Voice API + MCP need an API key?

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

### Can an agent call didlogic Voice API and Sinch Voice API + MCP without installing anything?

Yes. didlogic Voice API has a hosted endpoint at https://mcp.didlogic.com/mcp and Sinch Voice API + MCP at https://voice.api.sinch.com/v2.


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/didlogic-vs-sinch-voice.json, and with the fewest tokens: https://www.anchorterminal.com/compare/didlogic-vs-sinch-voice.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "didlogic", "b": "sinch-voice"}`. From a terminal: `anchor compare didlogic sinch-voice`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/didlogic.json and https://www.anchorterminal.com/api/v1/tools/sinch-voice.json

## Other comparisons with didlogic Voice API or Sinch Voice API + MCP

- [46elks Voice API vs didlogic Voice API](https://www.anchorterminal.com/compare/46elks-vs-didlogic.md)
- [46elks Voice API vs Sinch Voice API + MCP](https://www.anchorterminal.com/compare/46elks-vs-sinch-voice.md)
- [Bandwidth Voice API + MCP vs didlogic Voice API](https://www.anchorterminal.com/compare/bandwidth-voice-vs-didlogic.md)
- [Bandwidth Voice API + MCP vs Sinch Voice API + MCP](https://www.anchorterminal.com/compare/bandwidth-voice-vs-sinch-voice.md)
- [didlogic Voice API vs jambonz](https://www.anchorterminal.com/compare/didlogic-vs-jambonz.md)
- [Exotel Voice API + MCP vs Sinch Voice API + MCP](https://www.anchorterminal.com/compare/exotel-voice-vs-sinch-voice.md)
- [Infobip Calls API + MCP vs Sinch Voice API + MCP](https://www.anchorterminal.com/compare/infobip-calls-vs-sinch-voice.md)
- [jambonz vs Sinch Voice API + MCP](https://www.anchorterminal.com/compare/jambonz-vs-sinch-voice.md)
- [LiveKit Telephony vs Sinch Voice API + MCP](https://www.anchorterminal.com/compare/livekit-telephony-vs-sinch-voice.md)
- [Plivo Voice API vs Sinch Voice API + MCP](https://www.anchorterminal.com/compare/plivo-voice-vs-sinch-voice.md)
- [SignalWire Voice API vs Sinch Voice API + MCP](https://www.anchorterminal.com/compare/signalwire-voice-vs-sinch-voice.md)
- [Sinch Voice API + MCP vs Telnyx Voice API + MCP](https://www.anchorterminal.com/compare/sinch-voice-vs-telnyx-voice.md)
- [Sinch Voice API + MCP vs Twilio Programmable Voice API + MCP](https://www.anchorterminal.com/compare/sinch-voice-vs-twilio-voice.md)
- [Sinch Voice API + MCP vs Vonage Voice API + MCP](https://www.anchorterminal.com/compare/sinch-voice-vs-vonage-voice.md)
- [Sinch Voice API + MCP vs Voximplant](https://www.anchorterminal.com/compare/sinch-voice-vs-voximplant.md)
- [didlogic Voice API vs DIDWW Voice and Number Management API](https://www.anchorterminal.com/compare/didlogic-vs-didww-voice-and-number-management.md)
- [didlogic Voice API vs Exotel Voice API + MCP](https://www.anchorterminal.com/compare/didlogic-vs-exotel-voice.md)
- [didlogic Voice API vs Infobip Calls API + MCP](https://www.anchorterminal.com/compare/didlogic-vs-infobip-calls.md)
- [didlogic Voice API vs LiveKit Telephony](https://www.anchorterminal.com/compare/didlogic-vs-livekit-telephony.md)
- [didlogic Voice API vs Plivo Voice API](https://www.anchorterminal.com/compare/didlogic-vs-plivo-voice.md)
- [didlogic Voice API vs SignalWire Voice API](https://www.anchorterminal.com/compare/didlogic-vs-signalwire-voice.md)
- [didlogic Voice API vs Telnyx Voice API + MCP](https://www.anchorterminal.com/compare/didlogic-vs-telnyx-voice.md)
- [didlogic Voice API vs Twilio Programmable Voice API + MCP](https://www.anchorterminal.com/compare/didlogic-vs-twilio-voice.md)
- [didlogic Voice API vs Vonage Voice API + MCP](https://www.anchorterminal.com/compare/didlogic-vs-vonage-voice.md)
- [didlogic Voice API vs Voximplant](https://www.anchorterminal.com/compare/didlogic-vs-voximplant.md)
- [DIDWW Voice and Number Management API vs Sinch Voice API + MCP](https://www.anchorterminal.com/compare/didww-voice-and-number-management-vs-sinch-voice.md)

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Query this catalogue directly over MCP: https://www.anchorterminal.com/mcp (Streamable HTTP, no key). How: https://www.anchorterminal.com/agents/#mcp