Aurinko Email API

# Fix list: Aurinko Email API

From Anchor Terminal's listing at https://www.anchorterminal.com/tools/aurinko-email, the October 2026 research run, assessed 9 October 2026. Grade E, 44.2 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 Aurinko Email 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. Reliability, 40 out of 100, up to 12 more on the total

Why it scored 40: Graded as a hosted API. No status page is linked from the home page, the docs index or the description file (0). With no readable incident history the record scores 5. The description file gives a limit of 250 requests a second (15). It advises exponential backoff on 429 and 5xx and a retry on 408, and declares a `Retry-After` header only on the 408 of the get-message call. Sending takes no idempotency key (10). No SLA found, and the terms supply the service as is (0). The API is at `/v1` with no beta label (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.

## 2. Security & auth, 42 out of 100, up to 10.1 more on the total

Why it scored 42: Per-user OAuth with four mail scopes and `DELETE /v1/account/token` to revoke a token and the provider grant. The application's client ID and secret, sent as Basic auth with `X-Aurinko-Account-Id`, reach every connected account. The implicit grant is still supported though not recommended, returning the token in a URL fragment, and IMAP accounts give Aurinko a mailbox or app password (22). `Mail.Read` allows no writes and `Mail.Send` no reads, with no confirmation step for sends or deletes (13). Mail from third parties is returned with no injection guidance (0). No operator audit or request log found in the docs. Portal roles are documented (0). A security statement with a reporting address, security@yoxel.com, and penetration tests claimed. SOC 2 is not yet held, with no bug bounty and no security.txt (7).

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. Agent ergonomics, 49 out of 100, up to 8.3 more on the total

Why it scored 49: Graded on the REST API. `bodyType`, `stripQuoted` and `returnIds` shape responses, but message lists take no field selection and no page-size parameter (10). `pageToken` on lists, `q` search with 17 operators, a per-folder list, and delta tokens for updated and deleted mail (15). Errors carry `code`, `message`, `requestId` and the provider's `originalError`, with retry advice per status (14). No idempotency key on send, reply or draft send. Reads and delta sync are safe to repeat, and delete moves a message to Trash (4). Few required parameters, but no official SDK was found (6).

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.

## 4. Maintenance & community, 13 out of 100, up to 7.6 more on the total

Why it scored 13: No changelog or release notes found, so no API change can be dated. The docs sitemap dates the IMAP connection guide 22 September 2026 and the Email API guide 18 August 2026, counted as partial evidence of activity and not as a release (10). No dated changelog entries (0). Support is by email, with no public forum or issue tracker linked (3). No official SDK named in the docs (0). No public package or repository is linked from the pages read (0).

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.

## 5. Payments & pricing, 40 out of 100, up to 7.5 more on the total

Why it scored 40: No x402, MPP or L402 (0). Prices per active account a month published without login, $1.50 for email and $2 for all APIs, though the pricing page and the billing FAQ define the tiers differently (20). A 14-day trial, with a card asked for only when it ends (20). Signup is in a browser at app.aurinko.io, and each mailbox needs its owner's consent or password (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.

## 6. Schema & documentation, 67 out of 100, up to 5.4 more on the total

Why it scored 67: Public OpenAPI 3.0.0 description with 154 operations, 43 of them for email, read once from the file the reference page loads (25). `llms.txt` and a Markdown copy of every docs page (10). Every email operation has a summary but only 2 of 43 have a description. 61 of 85 parameters are described, and the guide has a table of 17 search operators with provider caveats (9). The scope list and `responseType` are enums, with few required fields marked (8). 34 of 43 email operations carry a cURL sample and the Errors section shows the JSON body, while operations declare little beyond 401 and a default response (10). `/v1` in the path and version 1.0.0, with no changelog found (5).

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. Transparency & trust, 44 out of 100, up to 4.9 more on the total

Made of editorial 27, provenance 60.

Why it scored 44: Closed service under a Terms of Services Agreement naming Yoxel, Inc. of California, last updated 11 August 2022 (15). The docs say message contents are passed through and never stored, with only IDs and thread relations cached, and the privacy policy commits to Google's Limited Use requirements. The policy gives no retention period, and no DPA was found (12). No deprecation policy or dated notices found (0). No sub-processor list or data location. The security statement names no cloud provider (0).

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):

- Domain age: aurinko.io, registered 2019-05-08 (7 years) (11 of 15)
- Terms of service: read, states 6 of the 7 things a reader expects, and has 2 clauses that cost points (5.1 of 10)
- Privacy policy: read, states 7 of the 8 things a reader expects (9.3 of 10)
- Status page: not found (0 of 10)
- Changelog: not found (0 of 10)
- security.txt: not found (0 of 10)

## 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.

- unchecked: whether a status page exists under an address the site does not link. None is linked from the home page, the docs index or the description file
- unchecked: the portal at app.aurinko.io behind login, so key rotation, team roles in practice, any request log and whether the trial asks for a card at signup were not seen
- unchecked: the vendor's GitHub organisation and any npm package. No page read links either, so no SDK, repository or download figure is recorded
- unchecked: the Follow-up Rules API guide, the Gmail Pub/Sub guide and the Google and Office 365 OAuth setup guides, which were not read
- The terms forbid robots, data mining and similar data extraction or gathering methods in connection with the Services. Recorded as a fact with no deduction. It matters before any probe is run
- Whether the SOC 2 Type I examination targeted for Q3 2026 has been completed. The security statement was last updated 18 June 2026
- Which of the two published descriptions of the $1.50 tier applies, and whether an email-only customer on IMAP pays $2
- Whether 429 responses carry a Retry-After header, and what page size message lists return. The description file does not say
- Maintenance is 13 here and 20 on aurinko-calendar. This dossier counts docs page dates as 10 for recency and records no repository, because none is linked

## Weaknesses

- No status page, incident history or SLA found, and the terms supply the service as is
- No idempotency key on `POST /v1/email/messages`, so a retried send can deliver twice
- No changelog, deprecation policy or official SDK found in the docs or on the site
- The application's client ID and secret, sent as Basic auth, reach every connected mailbox, and IMAP accounts hand Aurinko a mailbox password
- The terms of 11 August 2022 forbid robots and data extraction methods in connection with the Services. This matters before any probe is run

## 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.

- Use `https://api.aurinko.io/v1`. Several cURL examples in the docs print `https:/api.aurinko.io` with one slash, and one search example names the host `asti.aurinko.io`
- Do not retry `POST /v1/email/messages` blindly after a timeout. There is no idempotency key, so check Sent mail with `q=rfc822msgid:` or by subject first
- Call `POST /v1/email/sync` until `ready` is true, then page `/v1/email/sync/updated` with `pageToken` until a `nextDeltaToken` appears and store it
- Check the `omitted` array on message lists. Full bodies come only from Google and Office 365, and other providers return a snippet
- Request `Mail.Read` plus `Mail.Send` for read and send without modify rights. The docs example names `Mail.ReadOnly`, which is not in the scope list

## 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.