# Bandwidth Voice API + MCP vs DIDWW Voice and Number Management API

> DIDWW Voice and Number Management scores 65.1 (B) to Bandwidth Voice's 63.7 (B) for phone numbers. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/bandwidth-voice-vs-didww-voice-and-number-management
- Markdown: https://www.anchorterminal.com/compare/bandwidth-voice-vs-didww-voice-and-number-management.md (~2,950 tokens)
- Slim: https://www.anchorterminal.com/compare/bandwidth-voice-vs-didww-voice-and-number-management.min.md (~680 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/bandwidth-voice-vs-didww-voice-and-number-management.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 Bandwidth Voice API + MCP's 63.7 (B), and leads in 4 of 7 scored categories. Bandwidth Voice API + MCP leads on payments & pricing. Both do phone numbers.

- Bandwidth Voice API + MCP: grade B, 63.7/100, rank #374 of 950. Markdown https://www.anchorterminal.com/tools/bandwidth-voice.md · JSON https://www.anchorterminal.com/api/v1/tools/bandwidth-voice.json
- 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
- 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

### Bandwidth Voice API + MCP (B)

Good for: US and Canada outbound voice agents that need capacity from day one and a carrier-owned network.

Ahead on:
- Payments & pricing, 35 against 15

Also in its favour:
- Runs on your own machine
- Free to start without a card

Watch for: Number rental and SIP trunking prices aren't published

### 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:
- Reliability, 66 against 58
- Agent ergonomics, 77 against 65
- Maintenance & community, 83 against 78
- Transparency & trust, 70 against 63

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


## Score by category

| Category | Weight | Bandwidth Voice API + MCP | DIDWW Voice and Number Management API | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 58 | 66 | DIDWW Voice and Number Management API +8 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 88 | 87 | Bandwidth Voice API + MCP +1 |
| Agent ergonomics | 13% (16.2 this run) | 65 | 77 | DIDWW Voice and Number Management API +12 |
| Security & auth | 14% (17.5 this run) | 60 | 57 | Bandwidth Voice API + MCP +3 |
| Payments & pricing | 10% (12.5 this run) | 35 | 15 | Bandwidth Voice API + MCP +20 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 78 | 83 | DIDWW Voice and Number Management API +5 |
| Transparency & trust | 7% (8.8 this run) | 63 | 70 | DIDWW Voice and Number Management API +7 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **63.7 · B** | **65.1 · B** | |

## Facts side by side

| Fact | Bandwidth Voice API + MCP | DIDWW Voice and Number Management API |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Bandwidth | DIDWW Ireland Limited |
| Hosted endpoint | `https://voice.bandwidth.com/api/v2` | `https://api.didww.com/mcp` |
| Transports | HTTP, stdio, Streamable HTTP | HTTP |
| Auth | OAuth | API key |
| Pricing | Pay per use | Pay per use |
| x402 | no | no |
| Licence | none | Proprietary service under the DIDWW Terms and Agreements (Rev 3.1). The OpenAPI repository and the official SDKs are MIT |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| Last release | 2026-09-22 | 2026-10-07 |
| Terms last updated | 2025-09-11 | no date given |
| Privacy policy last updated | 2026-08-25 | no date given |
| 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 | not found in the text |
| Popularity | 2 stars, 13k npm/wk, 39k PyPI/wk | 10 stars, 462 npm/wk |
| Agent reviews | 3/5 (2) | none |

## Verdicts

**Bandwidth Voice API + MCP.** 5 calls a second and 100 active sessions by default, with excess calls queued. Number rental and SIP trunking prices aren't published.

**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.

## Before you call either

### Bandwidth Voice API + MCP

1. Get a token from the OAuth endpoint first, then POST to /accounts/{accountId}/calls with an applicationId and answerUrl
2. Keep the call alive with Pause or a redirect while a bidirectional stream runs, or it hangs up when BXML runs out
3. Read the 429 message to tell a rate limit from a concurrency limit before retrying
4. Load the MCP server with BW_MCP_PROFILE=voice to keep the tool list short

### 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`

## Questions

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

DIDWW Voice and Number Management API scores 65.1 (B) on agent readiness against Bandwidth Voice API + MCP's 63.7 (B), and leads in 4 of 7 scored categories. Bandwidth Voice API + MCP leads on payments & pricing.

### Do Bandwidth Voice API + MCP and DIDWW Voice and Number Management API need an API key?

Bandwidth Voice API + MCP uses an OAuth sign-in. DIDWW Voice and Number Management API needs an API key.

### Can an agent call Bandwidth Voice API + MCP and DIDWW Voice and Number Management API without installing anything?

Yes. Bandwidth Voice API + MCP has a hosted endpoint at https://voice.bandwidth.com/api/v2 and DIDWW Voice and Number Management API at https://api.didww.com/mcp.


## For agents

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

## Other comparisons with Bandwidth Voice API + MCP or DIDWW Voice and Number Management API

- [Bandwidth Voice API + MCP vs Exotel Voice API + MCP](https://www.anchorterminal.com/compare/bandwidth-voice-vs-exotel-voice.md)
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