Useanviluseanvil.com
Useanvil's API program shows strong fundamentals in API design and documentation discovery, giving partners a solid baseline to build against. The two areas that need the most attention are agent understanding and agent usability: agents currently lack a structured instructions file and rate-limit signaling, which means AI-powered integrations will struggle to self-serve reliably without guessing at constraints or context.
API DesignA clean, typed, well-governed API contract agents can reason about4 pass1 warn0 fail94A+
| Signal | Points | Findings | Rationale | |
|---|---|---|---|---|
| pass | Schema coverage & depthvia sdk | 25/25 | 25/25 (100%) public params are fully typed (no any/**kwargs). Analyzer confirms all methods have a derivable input schema. Investigated: sdk 100%, spec 75%. | 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. |
| warn | Machine-readable, versioned contractvia spec | 18.8/25 | info.version="1.0.0" set but no versioning scheme (URL / header / media type) detected. Investigated: spec 75%, docs 50%. | A current OpenAPI version with a declared versioning scheme lets agents reason about the contract. |
| 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 spec | 10/10 | 100% example coverage across params + responses. Investigated: spec 100%, docs 100%, sdk 100%. | 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 examples5 pass0 warn0 fail100A+
| Signal | Points | Findings | Rationale | |
|---|---|---|---|---|
| pass | Self-service developer portalvia docs | 29/29 | Signup page at https://app.useanvil.com/signup (CSR-rendered — body classifier inconclusive); free tier / sandbox documented in pricing/docs. Investigated: docs 100%. | Self-serve key/account creation is the fast first call for partners, with no sales gate. |
| pass | Quickstart presentvia docs | 25/25 | Quickstart at https://www.useanvil.com/docs/api/getting-started/ has a runnable sample in the .md variant (https://www.useanvil.com/docs/api/getting-started.md). Investigated: docs 100%. | A quickstart is the fastest path from landing page to first successful call. |
| pass | Code samples in docsvia docs | 18/18 | Code samples present on 12/20 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 | 50% description completeness. Investigated: spec 100%, sdk 17%. | Complete descriptions are the context humans and agents need to use endpoints. |
| pass | Changelog publishedvia sdk | 13/13 | Newest official SDK activity 119 day(s) ago. Investigated: sdk 100%, spec 0%, docs 0%. | A published changelog lets partners track changes without surprise. |
Agent DiscoveryPartners and their agents can find your APIs — llms.txt, registries, crawlable and reachable docs2 pass2 warn0 fail91A+
| Signal | Points | Findings | Rationale | |
|---|---|---|---|---|
| pass | Docs reachable, not hard auth-gatedvia docs | 30/30 | All 26 pages are publicly accessible. Investigated: docs 100%. | Agents can only index and fetch docs they can reach — past auth gates and over correct HTTP semantics. |
| pass | Registry & SDK presencevia cli | 28/28 | CLI documented with install instructions (download, brew). Investigated: cli 100%, sdk 75%, docs 0%, mcp 0%, wellknown 0%. | Listing in MCP registries and publishing SDKs puts the API where agents and their tooling look. |
| warn | llms.txt present, valid & comprehensivevia docs | 22.5/30 | No llms.txt directive found in HTML of any of 26 pages. Investigated: docs 75%, sdk 0%. | A valid, comprehensive llms.txt is the machine-readable entry point for agents. |
| warn | Crawlable / AEOvia wellknown | 9/12 | Sitemap present (9 entries) but carries no lastmod values. Investigated: wellknown 75%. | Bots allowed plus a fresh sitemap make docs findable by agent crawlers. |
Agent UnderstandingAgents can correctly interpret your APIs — machine-readable errors, consistent descriptions, structured data, parseable docs3 pass2 warn1 fail79B
| Signal | Points | Findings | Rationale | |
|---|---|---|---|---|
| pass | Machine-readable errors (RFC 9457)via spec | 28/28 | error codes documented in the docs site at https://www.useanvil.com/blog/product-news/etch-api-improved-notifications-error-handling/. Investigated: spec 100%, docs 100%, sdk 100%. | RFC 9457 problem details and a documented error-code inventory let agents parse failures without burning tokens. |
| pass | Operation purpose clarityvia spec | 25/25 | 100% 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 | 14.3/22 | 4 of 24 pages have substantive content differences between markdown and HTML (avg 10% missing). Investigated: docs 65%. | Server-rendered, clean, small-footprint docs are what an agent can cheaply fetch and parse correctly. |
| pass | Docs structured datavia docs | 8/8 | JSON-LD Article markup on 12/12 assessed pages (100%) with dateModified present. Investigated: docs 100%. | 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. |
| warn | Description consistency across surfaces | 0.2/7 | Mean pairwise description similarity across 3 surfaces (spec, docs, sdk) is 1% (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. |
Agent UsabilityAgents have the context to use your APIs reliably, not just find them2 pass1 warn1 fail72B
| Signal | Points | Findings | Rationale | |
|---|---|---|---|---|
| pass | Idempotency documentedvia spec | 27/27 | idempotency documented in the docs site at https://www.useanvil.com/blog/engineering/e-signature-audit-trail-schema-events-json-checklist/. Investigated: spec 100%, docs 100%, sdk 100%. | Documented idempotency lets agents retry safely. |
| pass | Sandbox separationvia sdk | 20/20 | Sandbox environments are exposed (sandbox). Investigated: sdk 100%, spec 0%, docs 0%. | An isolated environment lets agents exercise destructive operations safely. |
| warn | Runnable collection with test scriptsvia platform | 4.5/9 | No test scripts found in the workspace's collections. Investigated: platform 50%. | A public, maintained collection with assertions is runnable truth agents validate against. |
| 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. |
| 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 Useanvil — the evidence behind the score. All discovered from public sources; nothing here requires access to your systems.
| APIs analyzed | 4 — PDF APIs, Anvil APIs, Embeddable E-Signatures, Embeddable Webforms API |
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