Stytch Connected Apps by Stytch (Twilio)

# Fix list: Stytch Connected Apps

From Anchor Terminal's listing at https://www.anchorterminal.com/tools/stytch-connected-apps, the October 2026 research run, assessed 1 October 2026. Grade C, 60.8 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 Stytch Connected Apps: 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, 20 out of 100, up to 10 more on the total

Why it scored 20: No x402, MPP or L402 (0). Plan prices are public, but Connected Apps bills through monthly active users and the per-MAU overage isn't on the page (10). 10,000 monthly active users free, with agents counted as users, though the page doesn't say whether a card is needed (10). A person signs up in a browser to create a project (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, 66 out of 100, up to 6 more on the total

Why it scored 66: OAuth 2.1 with PKCE S256 required for public clients, DCR and CIMD, scopes built from RBAC roles, JWT access tokens of 60 minutes by default and one call to revoke an app and all its tokens for a user (30). Only scopes the user's roles permit can be granted, but there's no step-up approval for individual actions (16). The service returns tokens, not untrusted content (10). We found no audit log of grants, consents or revocations for Connected Apps (5). No security.txt on stytch.com, and stytch.com/security returns 404. Twilio's security page lists SOC 2 Type II and ISO 27001 with the warning that 'the credentials listed do not apply to every product', and runs a disclosure programme and a HackerOne bounty, but it doesn't mention Stytch (5).

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. Schema & documentation, 64 out of 100, up to 5.9 more on the total

Why it scored 64: We found no public OpenAPI file, though the authorisation server publishes standard OAuth metadata at `/.well-known/oauth-authorization-server` (10). llms.txt at stytch.com/docs/llms.txt (10). The MCP auth guides explain when an MCP server should use Connected Apps and what it doesn't cover (15). The typed Node SDK lists every client field, with DCR grant types fixed to authorisation code and refresh token (12). Worked examples in the guides, but we didn't check the error reference (5). The changelog now lives at stytch.com/docs/changelog, with dated entries to 14 August 2026, none of them about Connected Apps (12).

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.

## 4. Agent ergonomics, 65 out of 100, up to 5.7 more on the total

Why it scored 65: Token and metadata responses are small and fixed (20). We didn't confirm pagination on the Connected Apps client list (10). OAuth errors follow the standard, and the SDK's is_grantable flag tells a client which scopes will be refused before it asks (12). Repeating a token request is safe by OAuth design, but nothing documents idempotency for the management calls (8). Official SDKs in Node, Python and other languages, and DCR needs no credentials (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. Reliability, 73 out of 100, up to 5.4 more on the total

Why it scored 73: Atlassian Statuspage at status.stytch.com with component history (20). Since 1 July 2026 the feed shows only SMS problems on 1 and 9 September (57 minutes of 500s on a small share of SMS requests, then 2 hours 16 minutes of AT&T deliverability) and test database maintenance, none touching the OAuth endpoints (20). The rate limit page gives one number, 10 Password Authenticate calls an hour per email, and nothing for the OAuth, registration or token endpoints (5). A 429 is documented with exponential back-off in the UI, but no Retry-After and no idempotency guidance (8). 99.99 per cent SLA on Enterprise (10). Connected Apps isn't labelled preview (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.

## 6. Maintenance & community, 62 out of 100, up to 3.3 more on the total

Why it scored 62: The newest dated entry in the docs changelog is 14 August 2026, a pre-built UI parameter, 49 days ago. The Java SDK shipped 11.3.0 on 20 July (20 of 30). Three dated releases or entries in the last 90 days, 20 July (Java SDK), 31 July and 14 August (docs changelog) (20). Closed platform whose changelog moved into the docs in July and whose legal pages now point at Twilio (8 of 15). The Node, Python, Go and Ruby SDKs were all last tagged on 24 June 2026, Java on 20 July (8 of 15). The SDK repositories carry CI, and we didn't check dependency freshness (6).

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.

## 7. Transparency & trust, 66 out of 100, up to 3 more on the total

Made of editorial 42, provenance 90.

Why it scored 66: Closed platform under Twilio's terms (updated 16 July 2026), with the last Stytch terms kept at an archive link for existing customers (15). Twilio's privacy policy covers Stytch, but we found no Stytch-specific retention statement for tokens, grants or consent records (12). We found no deprecation policy or dated deprecation notices (0). Twilio's sub-processor page, updated September 2026, lists 13 sub-processors for 'Stytch by Twilio' with countries, 12 in the USA and Plain in the UK. Where Stytch's own platform is hosted isn't stated (15 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):

- 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.

- Rate limits for the OAuth token, registration and authorisation endpoints, which the rate limit page doesn't give.
- unchecked: whether an audit log of consents and revocations exists for Connected Apps. llms.txt didn't point us to one
- Whether Twilio's SOC 2, ISO 27001, disclosure programme and HackerOne bounty cover Stytch. Twilio's page says its credentials don't apply to every product and doesn't name Stytch
- Where Stytch's own platform is hosted. Twilio's sub-processor list gives countries for vendors, not for Stytch's servers
- Whether the backend SDKs are still maintained. None of Node, Python, Go or Ruby has been tagged since 24 June 2026

## Weaknesses

- No outbound token vault, so it can't hold your users' third-party tokens
- Node, Python, Go and Ruby SDKs last tagged 24 June 2026, and the docs changelog last moved on 14 August
- No published rate limits for the OAuth, registration or token endpoints
- No audit log of grants and revocations that we could find
- No security.txt, and Twilio's certifications page doesn't mention Stytch

## 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.

- Fetch `{project-domain}/.well-known/oauth-authorization-server` first and use the endpoints it returns, not hard-coded paths
- Register with `token_endpoint_auth_method` none and PKCE S256 when the agent can't keep a secret
- Expect a 401 with protected resource metadata from the MCP server, then register and authorise
- Ask only for scopes the user's roles can grant, or the consent page will refuse them
- Back off exponentially on a 429, since no Retry-After header is documented

## What the review panel asked for

- A stated card policy
- audit log of grants
- a Stytch security page

## 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.