DIDWW Voice and Number Management API

# Fix list: DIDWW Voice and Number Management API

From Anchor Terminal's listing at https://www.anchorterminal.com/tools/didww-voice-and-number-management, the October 2026 research run, assessed 9 October 2026. Grade B, 65.1 out of 100.

This is everything the published grade says the listing lacks, the biggest possible gain to the total first. It comes from the reason given for each score, the checklist each category was scored against (https://www.anchorterminal.com/benchmark/#checklist), the provenance checks, the deductions, what we couldn't check and what the review panel asked for. A fix counts at the next check, once it's public.

For a coding agent working on DIDWW Voice and Number Management API: work through the items below in the product, its docs and its public pages. Each category gives the reason for its score, with the points each checklist item earned, and the checklist itself, so the gap is the items that earned less than their points. Change the product, not the wording, and keep a note of what you changed and where it's published.

## 1. Payments & pricing, 15 out of 100, up to 10.6 more on the total

Why it scored 15: No x402, MPP or L402 found (0). The pricing page explains the charging models, the $30 minimum balance and the waived activation fee for API orders, and gives no price for a number or a minute. Price lists are sent on request or shown inside an account, so we gave 5 of 20 for the public model. The sandbox is free with no real card, and production needs a $30 prepaid balance before any order (10 of 20). An account is created by a person in a browser with email confirmation, keys are created in the User Panel, and MCP access needs a browser sign-in (0).

The checklist (https://www.anchorterminal.com/benchmark/#checklist-payments):

The published rubric, also on the [x402 page](https://www.anchorterminal.com/x402/).

- 40, a machine payment protocol (x402, MPP or L402) on the tool's own endpoints. 10 to 30 when it covers only some endpoints or only goes through a third party, and the note says which.
- 20, per-call or per-unit pricing published without a login. 10 for public plan-only pricing, 0 for "contact sales" or prices behind a login.
- 20, a free tier or trial that doesn't need a card.
- 20, autonomous onboarding, meaning an agent can get access without a person signing up in a browser (keyless use, x402, a programmatic key API).

Payment platforms and agent wallets rarely charge for their own API over a machine protocol, so the first line has steps for them, and the highest one that applies counts. 40 when x402, MPP or L402 runs on all their own endpoints, 30 when it runs on part of their own API, 25 when their merchants can accept one, 20 for running a facilitator, 15 for paying as a buyer, and 0 when the only protocol is their own. Merchant acceptance sits above a facilitator because the platform's own customers can charge agents through it, while a facilitator settles for sellers who wire up the protocol themselves. The counter-argument (a facilitator does more for the protocol as a whole) has a point. Each note says which step applied.

Open-source software you run yourself is scored on its hosted or paid option if it has one. A free, self-hosted package with nothing to buy gets 20, 20 and 20 for the last three lines, and 0 to 40 for the first only if it ships a payment protocol.

## 2. Security & auth, 57 out of 100, up to 7.5 more on the total

Why it scored 57: REST API keys are named, revocable and can be limited to source IP addresses. Several keys can exist. They reach the whole account, with no scopes (22 of 30). No read-only key was found and an order placed through the API is charged with no confirmation step. The sandbox is separate, panel users have six roles, and the MCP server applies those roles and a server-side preview and confirmation before purchases and deletions (9 of 20). API replies are mostly the account's own records. Free-text descriptions, caller numbers in call records and inbound SMS routed to the customer are untrusted, and the MCP docs warn that clients can make mistakes. No prompt-injection guidance was found (9 of 15). DID history records the method of each change, such as `api3` or `user_panel`, for 90 days, and connected MCP clients are listed with recent activity and IP address. No log of API requests was found (8 of 15). The docs say DIDWW holds ISO/IEC 27001:2022 certification from Bureau Veritas. The certificate was not seen. No security.txt, disclosure policy, bug bounty or published advisory was found. Callbacks are signed with HMAC SHA-1 (9 of 20).

The checklist (https://www.anchorterminal.com/benchmark/#checklist-security):

- 0 to 30, the credential model. 30 for OAuth 2.1 with scopes, or scoped and revocable keys with rotation. 20 for plain revocable API keys. 10 for one all-powerful key. 10 off when a secret can travel in a URL query string as a documented option.
- 0 to 20, read-only or least-privilege modes, and confirmation or approval for destructive actions.
- 0 to 15, prompt-injection posture where the tool returns untrusted content (documented mitigations or guidance). A tool that returns no untrusted content gets 10.
- 0 to 15, audit logs or per-call visibility for the operator.
- 0 to 20, a security programme. security.txt or a disclosure policy, a bug bounty, SOC 2 or ISO 27001, advisories handled in public.

Models are read for retention, whether API data trains models (and whether that's off by default), zero-retention options and certifications. Frameworks for telemetry defaults, approval hooks, guardrails and sandboxing.

## 3. Reliability, 66 out of 100, up to 6.8 more on the total

Why it scored 66: Graded as a hosted service on the REST API v3. A public status page on Instatus lists eight components, among them DIDWW API, Inbound Voice and Outbound Voice (20). Its 90 day history shows no incident on the API component, a 13 hour 9 minute Inbound Voice incident for Guatemala numbers on 4 October 2026, one of 3 hours 56 minutes for Mexico numbers on 3 October, a 47 minute phone.systems incident on 5 October and one planned maintenance. Both voice incidents were limited to one country's numbers, so we read them between minor and major (15 of 30). Rate limits are published as 20 requests a second per API key (15). `429` is documented with advice to wait before retrying. No `Retry-After` header and no idempotency key were found for the REST API. Callbacks are retried nine times at a widening interval (6 of 15). No SLA was found, and the terms give no warranty of continuous service (0). API v3 is generally available with a sandbox. Outbound trunks need an approved application (10).

The checklist (https://www.anchorterminal.com/benchmark/#checklist-reliability):

Hosted APIs, MCP servers, models and platforms.

- 20, a public status page with component history (Statuspage, Instatus, BetterStack or the vendor's own).
- 0 to 30, the incident record for the last 90 days on that page. 30 for a clean record or trivial incidents only, 20 for minor incidents only, 10 for one major outage (an hour or more of a core API down, or errors across the board), 0 for several. 5 when there's no history we could read, and the note says so.
- 15, rate limits documented with numbers.
- 15, documented 429 or overload handling (Retry-After, backoff guidance), and idempotency keys or safe-retry guidance where writes are involved.
- 10, an SLA published for any paid tier.
- 10, the surface agents use is generally available, not beta or preview.

Local packages, SDKs, frameworks and stdio MCP servers.

- 20, installs from an official package with supported runtimes stated.
- 25, a public CI and test suite, passing on the default branch.
- 0 to 25, open crash or regression issues relative to activity (25 for few and handled, 0 for many, old and unanswered).
- 15, semver discipline and breaking changes called out in a changelog.
- 15, version 1.0 or later, or declared stable.

Protocols are read from their reference implementations, the public facilitators or servers, spec stability and test vectors.

## 4. Agent ergonomics, 77 out of 100, up to 3.7 more on the total

Why it scored 77: Sparse fieldsets with `fields[...]`, `include` for related resources and `page[size]` let a caller size replies. JSON:API envelopes add some weight (22 of 25). Pagination defaults to 50 and allows 100 a page, with documented filters and sorting on each collection (20). Errors are JSON:API objects with `title`, `detail`, `code` and `source.pointer`, and an insufficient balance error returns the order cost and the available balance (17 of 20). No idempotency key was found on `POST /orders`, which charges the balance at once, so a retried request can buy twice. Reservations and order polling help a caller check first, and MCP confirmations work once (5 of 20). Every request needs an `Accept` header and writes need a JSON:API body. Official SDKs exist for TypeScript, Python, PHP, Java, Go, .NET and Ruby (13 of 15).

The checklist (https://www.anchorterminal.com/benchmark/#checklist-ergonomics):

- 0 to 25, context cost. For MCP, the number and size of the tool definitions (25 for ten or fewer compact tools, 15 for 11 to 30, 5 for more than 30, plus up to 10 back for toolsets, dynamic loading or read-only subsets). For APIs, whether responses can be sized (field selection, limits, summaries).
- 20, pagination, filtering and output-size controls.
- 20, actionable, documented error responses, codes and messages an agent can recover from.
- 20, idempotency or safe retries, and for MCP the `readOnlyHint` and `destructiveHint` annotations.
- 15, sensible defaults, few required parameters, and official SDKs in at least two languages.

Models are read for tool use, structured output, prompt caching, context length, batch and SDKs. Frameworks for how much code and how many defaults a tool-calling agent with MCP needs.

## 5. Transparency & trust, 70 out of 100, up to 2.6 more on the total

Made of editorial 55, provenance 85.

Why it scored 70: The service is closed, under the DIDWW Terms and Agreements, Rev 3.1, with a named Irish legal entity. The OpenAPI document and SDKs are MIT (17 of 30). The Privacy Notice, Rev 2.1, lists the data collected and the legal basis for each kind, and says data may be processed in the USA, Singapore and Germany among other countries. It gives no retention periods, and no data processing agreement was found. The MCP data handling page says what an MCP client receives and what DIDWW logs (14 of 30). A published policy says released dated API versions are not retired, and deprecated fields are marked in the schema. The callback change of 6 October 2026 altered a released version without an entry on its changelog page (16 of 20). Points of presence are listed with street addresses. No sub-processor list was found, and payment processors are not named in the notice (8 of 20).

The checklist (https://www.anchorterminal.com/benchmark/#checklist-transparency):

- 0 to 30, source availability and licence clarity. 30 for open source under an OSI licence, 15 for closed with clear terms, 0 for unclear terms.
- 0 to 30, data handling and retention statements that agree with each other (privacy policy, DPA, retention periods, subprocessors).
- 0 to 20, a deprecation policy or notices with dates.
- 0 to 20, telemetry disclosed with an opt-out (local software), or subprocessors and data locations disclosed (hosted).

The other half of Transparency and trust is the provenance score, computed from checked facts (below). The category score is the mean of the two.

Provenance checks not met in full (half of this category, computed from checked facts):

- Terms of service: read, states 4 of the 7 things a reader expects (7.4 of 10)
- Privacy policy: read, states 5 of the 8 things a reader expects (7.8 of 10)
- security.txt: not found (0 of 10)

## 6. Schema & documentation, 87 out of 100, up to 2.1 more on the total

Why it scored 87: A public OpenAPI 3.0.3 document for version 2026-04-16 describes 107 operations on 67 paths with 242 schemas, in JSON and YAML, with a discovery manifest at `/.well-known/openapi.json` (25). Both sites publish llms.txt indexes and a Markdown twin of each page (10). 105 of 107 operations carry a description, and those read say what the call does, what it charges and what to do next, such as polling an order until it leaves `pending` (16 of 20). The document has 325 enums, required fields and patterns, within JSON:API envelopes that need nested `data`, `attributes` and `relationships` objects (13 of 15). 52 of 107 operations have examples. Responses 400, 401, 403, 404, 406, 415 and 422 are documented and an error object page explains codes. `429` is in the prose docs and not in the OpenAPI responses (12 of 15). Versions are dated and selected by header, with a changelog page per version. Entries are not dated, and the callback secret change of 6 October 2026 is not on the 2026-04-16 changelog page (11 of 15).

The checklist (https://www.anchorterminal.com/benchmark/#checklist-schema):

APIs and MCP servers.

- 25, a machine-readable contract (a public OpenAPI file or similar; for MCP, typed JSON Schema inputs on every tool).
- 10, llms.txt or Markdown docs served for agents.
- 0 to 20, descriptions that say what a tool is for, when to use it and when not to, read from the tool definitions in the source or the API reference.
- 0 to 15, typed inputs with enums, constraints and required fields, and no free-form JSON blobs.
- 0 to 15, examples and documented error responses.
- 15, versioning and a public changelog.

Models are read from the API reference, the OpenAPI file, llms.txt, the structured-output and tool-use docs and the model cards. Frameworks from docs a model can follow, typed interfaces, examples and the API reference.

## 7. Maintenance & community, 83 out of 100, up to 1.5 more on the total

Why it scored 83: The public OpenAPI document was last revised on 6 October 2026 and the Ruby, Python and TypeScript SDKs were tagged on 7 October 2026 (30). The OpenAPI repository has six dated revisions of the 2026-04-16 document from 20 August to 6 October 2026 (20). As a closed service, responsiveness is read from the public changelog, a support address with a stated 24 hour service, and GitHub, where the three repositories checked have no open issues and a pull request from a fork of the TypeScript SDK was merged on 3 September 2026, a day after its commit (11 of 15). Official SDKs for seven languages follow API version 2026-04-16 (15). The SDK repositories carry CI workflows, tests and lock files. We did not see the latest run results (7 of 10).

The checklist (https://www.anchorterminal.com/benchmark/#checklist-maintenance):

- 0 to 30, time since the last release, or the last published model or API change for a closed service. 30 within 30 days, 20 within 90, 10 within 180, 0 older.
- 20, at least three releases or dated changelog entries in the last 90 days.
- 0 to 25, responsiveness. Issues and pull requests answered on GitHub (the open issues and how recent the replies are). For closed services, a public changelog and a support or community channel that answers, 0 to 15.
- 15, presence in the official MCP registry under a verified namespace (MCP servers), or current official SDKs (APIs and models).
- 10, package health, current dependencies and CI.

Models are read for deprecation notice periods and model churn rather than release counts.

## What we couldn't check

What we couldn't read counted as absent. Publishing it on a page a plain HTTP fetch can read (not only in a browser) lets the next check count it.

- The lead named the REST API and SIP transport and did not mention the remote MCP server at `https://api.didww.com/mcp`. The legal entity is DIDWW Ireland Limited
- Category fit. DIDWW sells numbers and SIP trunks and has no API for placing, streaming, transferring or recording a call, so only `voice.numbers` and `voice.sip` are listed and `voice.calls` is left out
- Whether the callback secret change of 6 October 2026 stopped callbacks for accounts that had signed them with an API key, and whether customers were told in advance
- Whether the MCP server has 81 or 82 tools, and whether its tools carry `readOnlyHint` and `destructiveHint` annotations. The server card lists names and descriptions only
- What a number, a channel and a minute cost. No price list was read, and `unitPrices` is empty
- Whether a `Retry-After` header comes with `429` on the REST API
- The terms forbid auto-dialling, telemarketing and continuous or extensive call forwarding. This matters before any probe places calls
- unchecked: the OAuth metadata and every other path on api.didww.com, because its robots.txt answered 403 and no further request was sent to that host
- unchecked: the ISO/IEC 27001 certificate, the User Panel and the sign-up form, including whether sign-up asks for a card
- unchecked: the per-endpoint reference pages, the outbound trunk security page in full, the Postman workspace and news.didww.com
- unchecked: weekly downloads of the `didww` Python package, and the result of the latest CI runs on the SDK repositories
- On 6 October 2026 the API description for released version 2026-04-16 moved callback signing from an API key to a separate callback secret, with no entry on that version's changelog page. Whether existing integrations stopped receiving callbacks, or customers were told, was not established, so no deduction was taken (https://github.com/didww/didww-api-3-openapi/commit/9ee36774515e26b433cf84c742ce7d30f8beed89).

## Weaknesses

- 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
- REST API keys reach the whole account. An optional source IP allow list is the only restriction, with no scopes and no read-only key
- No idempotency key was found on `POST /orders`, which charges the prepaid balance at once, so a retried request can buy twice
- The API cannot place, answer, record or stream a call. Calls run over the customer's own SIP system, and Call Events webhooks are switched on by support
- Outbound trunks need an approved application from a business account with a company name and VAT or tax ID
- Callback signing moved from an API key to a separate callback secret on 6 October 2026, and the 2026-04-16 changelog page does not record it
- No security.txt, disclosure policy, bug bounty, uptime SLA, data processing agreement or sub-processor list was found
- The terms forbid auto-dialling, telemarketing and continuous or extensive call forwarding, which matters before an agent places outbound calls

## What costs an agent a turn today

The notes we give agents before they call it. Each one is a workaround an agent shouldn't need.

- 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
- 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
- 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
- Stay under 20 requests a second per key. On `429` wait before retrying, since no `Retry-After` header is documented
- Use `fields[...]`, `filter[...]`, `include` and `page[size]` (default 50, maximum 100) to keep JSON:API replies small
- Check `GET /address_requirements` before buying a number. Many countries need a verified identity and address, and the sandbox cannot run identity verification
- 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`

## When it's done

Send what changed and where it's published as a dispute (https://www.anchorterminal.com/builders/#disputes, or `POST https://www.anchorterminal.com/api/v1/contact` with `"kind": "dispute"`). Disputes are answered in public, and the listing is checked again by the same checklist. Paying for an audit or a listing claim changes nothing here.