Klaviyoklaviyo.com
Klaviyo's API program shows meaningful strengths in documentation parseability and crawlability, but two areas are holding back partner and agent success: agents cannot reliably discover or operate against the API without manual intervention, and partners lack the runnable, reliability-anchored context needed to build production-grade integrations quickly. The highest-priority work is making the API surface machine-discoverable and operationally trustworthy — closing these gaps will let partners and their agents move from evaluation to live integration without friction or guesswork.
API DesignA clean, typed, well-governed API contract agents can reason about5 pass0 warn0 fail100A+
| Signal | Points | Findings | Rationale | |
|---|---|---|---|---|
| pass | Machine-readable, versioned contractvia spec | 25/25 | Versioning declared (info.version="2026-07-15") and media-type-versioning detected. Investigated: spec 100%, docs 100%. | A current OpenAPI version with a declared versioning scheme lets agents reason about the contract. |
| pass | Schema coverage & depthvia sdk | 25/25 | 3/3 (100%) public params are fully typed (no any/**kwargs). Analyzer confirms all methods have a derivable input schema. Investigated: sdk 100%, spec 33%. | Typed, complete request/response schemas are what make agent function-calling possible. |
| pass | Auth declared & discoverablevia spec | 25/25 | Authentication required (global or on every operation). Investigated: spec 100%, docs 100%. | Agents can only authenticate when auth is declared, scoped, and discoverable. |
| pass | Security & governance hygienevia spec | 15/15 | No credential-shaped strings detected in spec. Investigated: spec 100%, wellknown 0%. | No leaked secrets, no critical lint violations, no OWASP API Top-10 spec smells, and a published vulnerability-disclosure channel. |
| pass | Example coveragevia docs | 10/10 | Code samples present on 1/5 pages across 1 language(s); broader multi-language coverage missing. Investigated: docs 100%, sdk 100%, spec 0%. | Examples carry shape semantics schemas under-specify — for humans and agents alike. |
Developer ExperienceThe context both developers and agents need to integrate fast — onboarding, code samples, complete descriptions and worked examples4 pass0 warn1 fail79B
| Signal | Points | Findings | Rationale | |
|---|---|---|---|---|
| pass | Self-service developer portalvia docs | 29/29 | Self-service signup at https://www.klaviyo.com/sign-up; free tier / sandbox documented. Investigated: docs 100%. | Self-serve key/account creation is the fast first call for partners, with no sales gate. |
| pass | Code samples in docsvia docs | 18/18 | Code samples present on 1/5 pages across 1 language(s); broader multi-language coverage missing. Investigated: docs 100%. | Multi-language samples shorten time-to-first-call. |
| pass | Description completenessvia spec | 15/15 | 98% of operations + parameters have substantive descriptions. Investigated: spec 100%, sdk 100%. | Complete descriptions are the context humans and agents need to use endpoints. |
| pass | Changelog publishedvia sdk | 13/13 | Newest official SDK activity 0 day(s) ago. Investigated: sdk 100%, spec 0%, docs 0%. | A published changelog lets partners track changes without surprise. |
| fail | Quickstart presentvia docs | 0/25 | No quickstart/getting-started page found at the conventional paths. Investigated: docs 0%. | A quickstart is the fastest path from landing page to first successful call. |
Agent DiscoveryPartners and their agents can find your APIs — llms.txt, registries, crawlable and reachable docs1 pass2 warn1 fail61C
| Signal | Points | Findings | Rationale | |
|---|---|---|---|---|
| pass | Registry & SDK presencevia docs | 28/28 | Indexed on Context7 (websites/developers_klaviyo_en, 8780 snippets). Investigated: docs 100%, sdk 100%, cli 100%, mcp 0%, wellknown 0%. | Listing in MCP registries and publishing SDKs puts the API where agents and their tooling look. |
| warn | Docs reachable, not hard auth-gatedvia docs | 15/30 | 1 JavaScript redirect(s) detected across 1 pages. Investigated: docs 50%. | Agents can only index and fetch docs they can reach — past auth gates and over correct HTTP semantics. |
| warn | Crawlable / AEOvia wellknown | 6/12 | No sitemap discoverable via robots.txt or /sitemap.xml on the docs host. Investigated: wellknown 50%. | Bots allowed plus a fresh sitemap make docs findable by agent crawlers. |
| fail | llms.txt present, valid & comprehensivevia docs | 0/30 | No llms.txt found at any candidate location (https://developers.klaviyo.com/en/llms.txt, https://developers.klaviyo.com/llms.txt, https://developers.klaviyo.com/docs/llms.txt). Investigated: docs 0%, sdk 0%. | A valid, comprehensive llms.txt is the machine-readable entry point for agents. |
Agent UnderstandingAgents can correctly interpret your APIs — machine-readable errors, consistent descriptions, structured data, parseable docs2 pass2 warn2 fail74B
| Signal | Points | Findings | Rationale | |
|---|---|---|---|---|
| pass | Machine-readable errors (RFC 9457)via sdk | 28/28 | Single base error "KlaviyoAPIException" with 6 subclasses. Investigated: sdk 100%, spec 0%, docs 0%. | RFC 9457 problem details and a documented error-code inventory let agents parse failures without burning tokens. |
| pass | Operation purpose clarityvia spec | 25/25 | 97% of operations have a clear summary + operationId an agent can select on. Investigated: spec 100%. | Agents select the right endpoint from its summary + operationId; clear, named operations make tool-selection reliable — the strongest driver of correct tool choice. |
| warn | Agent-navigable, token-efficient docsvia docs | 14.1/22 | No pages support .md URLs (0/1 tested). Investigated: docs 64%. | Server-rendered, clean, small-footprint docs are what an agent can cheaply fetch and parse correctly. |
| warn | Description consistency across surfaces | 1/7 | Mean pairwise description similarity across 2 surfaces (spec, docs) is 5% (threshold 35% for full credit). | Every surface tells the same story about what the product is. |
| fail | Agent instructions file (AGENTS.md)via wellknown | 0/10 | No AGENTS.md at the site root or /.well-known/. Investigated: wellknown 0%. | An AGENTS.md gives coding agents explicit setup, auth, and usage instructions to interpret and operate the API — beyond llms.txt's link index. |
| fail | Docs structured datavia docs | 0/8 | Neither JSON-LD nor OpenGraph/meta tags detected across 3 assessed pages (3 JS-rendered). Investigated: docs 0%. | Structured data (JSON-LD/schema.org) on docs pages gives agents an unambiguous parse target and is what answer engines cite. Detected on the JS-rendered head (Firecrawl) for a bounded page budget, so JS-injected JSON-LD is now caught; pages we can't render are excluded rather than failed. |
Agent UsabilityAgents have the context to use your APIs reliably, not just find them0 pass1 warn3 fail43F
| Signal | Points | Findings | Rationale | |
|---|---|---|---|---|
| warn | Sandbox separationvia sdk | 10/20 | No test-mode flag or sandbox environment is exposed. Investigated: sdk 50%, spec 0%, docs 0%. | An isolated environment lets agents exercise destructive operations safely. |
| fail | Idempotency documentedvia spec | 0/27 | 0% of mutating operations document idempotency. Investigated: spec 0%, docs 0%, sdk 0%. | Documented idempotency lets agents retry safely. |
| fail | Rate-limit signalingvia spec | 0/22 | No rate-limit response headers documented. Investigated: spec 0%, docs 0%. | Machine-readable rate-limit headers let agents throttle adaptively. |
| fail | Runnable collection with test scriptsvia platform | 0/9 | No public Postman workspace discovered for the org. Investigated: platform 0%. | A public, maintained collection with assertions is runnable truth agents validate against. |
| na | Pagination documented & consistent | —/22 | No surface produced evidence for this capability in this run. | Consistent, documented pagination lets agents traverse collections. |
Resources Discovered
The public resources we found for Klaviyo — the evidence behind the score. All discovered from public sources; nothing here requires access to your systems.
| Agent hints | Context7 (8,780) |
|---|---|
| APIs analyzed | 1 — Klaviyo API |