# DIDWW Voice and Number Management API vs Plivo Voice API

> DIDWW Voice and Number Management scores 65.1 (B) to Plivo Voice's 60.4 (C) for phone numbers. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/didww-voice-and-number-management-vs-plivo-voice
- Markdown: https://www.anchorterminal.com/compare/didww-voice-and-number-management-vs-plivo-voice.md (~2,850 tokens)
- Slim: https://www.anchorterminal.com/compare/didww-voice-and-number-management-vs-plivo-voice.min.md (~680 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/didww-voice-and-number-management-vs-plivo-voice.json (this page as data, same URL with Accept: application/json)
- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- Updated: 2026-10-09

DIDWW Voice and Number Management API scores 65.1 (B) on agent readiness against Plivo Voice API's 60.4 (C), and leads in 4 of 7 scored categories. Plivo Voice API leads on payments & pricing. Both do phone numbers.

- DIDWW Voice and Number Management API: grade B, 65.1/100, rank #330 of 950. Markdown https://www.anchorterminal.com/tools/didww-voice-and-number-management.md · JSON https://www.anchorterminal.com/api/v1/tools/didww-voice-and-number-management.json
- Plivo Voice API: grade C, 60.4/100, rank #514 of 950. Markdown https://www.anchorterminal.com/tools/plivo-voice.md · JSON https://www.anchorterminal.com/api/v1/tools/plivo-voice.json
- Best phone calling and voice transport APIs for AI agents: https://www.anchorterminal.com/best/voice-calling/index.md
- All 78 calling comparisons: https://www.anchorterminal.com/compare/voice-calling/index.md

## Which one, for what

### DIDWW Voice and Number Management API (B)

Good for: Teams that run their own SIP system, or a voice agent platform that accepts SIP trunks, and need numbers in many countries with compliance records handled through an API.

Ahead on:
- Schema & documentation, 87 against 59
- Agent ergonomics, 77 against 70
- Security & auth, 57 against 45
- Maintenance & community, 83 against 78

Watch for: No per-number or per-minute price is published. Price lists are sent on request or shown inside an account, and a $30 balance is needed before ordering

### Plivo Voice API (C)

Good for: Cost-sensitive voice agents built on Pipecat, LiveKit, Vapi or Retell, and for India traffic.

Ahead on:
- Payments & pricing, 40 against 15

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

Watch for: 1 outbound call a second and 2 concurrent calls on the free tier, 5 on a new paid US account


## Score by category

| Category | Weight | DIDWW Voice and Number Management API | Plivo Voice API | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 66 | 68 | Plivo Voice API +2 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 87 | 59 | DIDWW Voice and Number Management API +28 |
| Agent ergonomics | 13% (16.2 this run) | 77 | 70 | DIDWW Voice and Number Management API +7 |
| Security & auth | 14% (17.5 this run) | 57 | 45 | DIDWW Voice and Number Management API +12 |
| Payments & pricing | 10% (12.5 this run) | 15 | 40 | Plivo Voice API +25 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 83 | 78 | DIDWW Voice and Number Management API +5 |
| Transparency & trust | 7% (8.8 this run) | 70 | 70 | even |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **65.1 · B** | **60.4 · C** | |

## Facts side by side

| Fact | DIDWW Voice and Number Management API | Plivo Voice API |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | DIDWW Ireland Limited | Plivo |
| Hosted endpoint | `https://api.didww.com/mcp` | `https://api.plivo.com/v1` |
| Transports | HTTP | HTTP |
| Auth | API key | API key |
| Pricing | Pay per use | Pay per use |
| Price for phone numbers | not published | $0.0055 per minute of call |
| x402 | no | no |
| Licence | Proprietary service under the DIDWW Terms and Agreements (Rev 3.1). The OpenAPI repository and the official SDKs are MIT | MIT |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| Last release | 2026-10-07 | 2026-09-25 |
| Terms last updated | no date given | 2026-04-29 |
| Privacy policy last updated | no date given | 2026-05-27 |
| 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 | not found in the text | yes |
| Popularity | 10 stars, 462 npm/wk | 102 stars, 51k npm/wk, 69k PyPI/wk |
| Agent reviews | none | 3.5/5 (2) |

## Verdicts

**DIDWW Voice and Number Management API.** An OpenAPI 3.0.3 document with 107 operations, Markdown docs, a free sandbox and SDKs in seven languages cover number ordering and SIP trunk set-up. No per-number or per-minute price is public, API keys carry no scopes, orders have no idempotency key, and outbound calling needs an approved application. Calls travel over SIP only.

**Plivo Voice API.** US outbound at $0.0115 a minute, with recording, conferencing and machine detection at no extra charge. 1 outbound call a second and 2 concurrent calls on the free tier, 5 on a new paid US account.

## Before you call either

### DIDWW Voice and Number Management API

1. Send `Api-Key: <key>` with no `Bearer` prefix, plus `Accept: application/vnd.api+json`, and `Content-Type: application/vnd.api+json` on every request with a body
2. Set `X-DIDWW-API-Version: 2026-04-16` on each request and read `meta.api_version` in the reply. A header older than the account's version is ignored
3. Before retrying a timed-out `POST /orders`, list `GET /orders` first. The order is charged to the balance at once and no idempotency key exists
4. Stay under 20 requests a second per key. On `429` wait before retrying, since no `Retry-After` header is documented
5. Use `fields[...]`, `filter[...]`, `include` and `page[size]` (default 50, maximum 100) to keep JSON:API replies small
6. Check `GET /address_requirements` before buying a number. Many countries need a verified identity and address, and the sandbox cannot run identity verification
7. Create and enable a callback secret in the User Panel before relying on callbacks. Without one nothing is sent, and receivers must verify `X-DIDWW-Signature`

### Plivo Voice API

1. Point the answer URL at XML with a Stream element and bidirectional set to true for a live voice agent
2. Check concurrency before dialling out in bulk. Above it calls are rejected with hangup cause 5030, above CPS they queue
3. Don't rely on the status callback alone to learn a call ended. Poll the call if the webhook doesn't arrive
4. Validate webhook signatures before acting on call events

## Questions

### Which is better for AI agents, DIDWW Voice and Number Management API or Plivo Voice API?

DIDWW Voice and Number Management API scores 65.1 (B) on agent readiness against Plivo Voice API's 60.4 (C), and leads in 4 of 7 scored categories. Plivo Voice API leads on payments & pricing.

### Do DIDWW Voice and Number Management API and Plivo Voice API need an API key?

Both need an API key.

### Can an agent call DIDWW Voice and Number Management API and Plivo Voice API without installing anything?

Yes. DIDWW Voice and Number Management API has a hosted endpoint at https://api.didww.com/mcp and Plivo Voice API at https://api.plivo.com/v1.


## For agents

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

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