Vercelvercel.com
Vercel's API program shows strong foundational API design, with a clean, well-typed contract that partners and agents can build against confidently. The areas most in need of attention are agent understanding and agent discovery: partners' AI agents currently lack the structured, machine-readable context they need to interpret and act on the API surface without guessing, and the documentation is not surfaced in ways that let agents — or the partners directing them — find and consume it autonomously.
API DesignA clean, typed, well-governed API contract agents can reason about4 pass1 warn0 fail100A+
| Signal | Points | Findings | Rationale | |
|---|---|---|---|---|
| pass | Machine-readable, versioned contractvia spec | 25/25 | The API declares version "0.0.1" and uses url-based versioning, so an agent can pin to a stable contract. Investigated: spec 100%, docs 100%, cli 50%. | A current OpenAPI version with a declared versioning scheme lets agents reason about the contract. |
| pass | Auth declared & discoverablevia docs | 25/25 | authentication is documented on the docs site at https://vercel.com/login?next=%2Fauthentication, even though it isn't declared in the API spec. Investigated: docs 100%, wellknown 100%, spec 50%, cli 0%. | Agents can only authenticate when auth is declared, scoped, and discoverable. |
| warn | Schema coverage & depthvia sdk | 24.9/25 | 734/735 (100%) public params are fully typed (no any/**kwargs). Analyzer reports not all methods have a derivable input schema. Investigated: sdk 100%, spec 67%. | Typed, complete request/response schemas are what make agent function-calling possible. |
| pass | Security & governance hygienevia spec | 15/15 | No credential-shaped strings detected in spec. Investigated: spec 100%, sdk 100%, wellknown 100%. | 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 | Only 51% of parameters and responses (888 of 1758) include examples (target 80%+), so an agent guesses payload shapes the schema under-specifies. Investigated: spec 100%, docs 100%, sdk 100%, cli 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 examples5 pass0 warn0 fail100A+
| Signal | Points | Findings | Rationale | |
|---|---|---|---|---|
| pass | Self-service developer portalvia docs | 29/29 | Signup page at https://vercel.com/signup (client-rendered, so its contents couldn't be classified); free tier or sandbox is 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://vercel.com/docs/getting-started-with-vercel has a runnable code sample in its plain-text .md variant (https://vercel.com/docs/getting-started-with-vercel.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 | Docs show code samples in 3 language(s) (top: typescript, curl, javascript), and 5 of 20 sampled pages offer ≥ 2 languages side by side. Investigated: docs 100%. | Multi-language samples shorten time-to-first-call. |
| pass | Description completenessvia spec | 15/15 | Only 83% of operations and parameters have substantive descriptions (326 of 377 ops, 1051 of 1324 params; target 90%+). Investigated: spec 100%, sdk 95%. | Complete descriptions are the context humans and agents need to use endpoints. |
| pass | Changelog publishedvia spec | 13/13 | changelog is documented on the docs site at https://vercel.com/docs/cli/release-notes, even though it isn't declared in the API spec. Investigated: spec 100%, docs 100%, sdk 100%. | 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 fail82A
| Signal | Points | Findings | Rationale | |
|---|---|---|---|---|
| pass | Registry & SDK presencevia docs | 28/28 | Indexed on Context7 (websites/vercel, 14255 snippets). Investigated: docs 100%, mcp 100%, sdk 83%, cli 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 | 22.5/30 | 1 of 50 sampled pages return 200 for non-existent URLs (soft 404). Investigated: docs 75%. | Agents can only index and fetch docs they can reach — past auth gates and over correct HTTP semantics. |
| warn | llms.txt present, valid & comprehensivevia docs | 16.9/30 | No llms.txt directive found in HTML of any of 50 sampled pages. Investigated: docs 56%, sdk 0%. | A valid, comprehensive llms.txt is the machine-readable entry point for agents. |
| pass | Crawlable / AEOvia wellknown | 12/12 | robots.txt lets all monitored AI crawlers reach the docs paths. Investigated: wellknown 100%. | 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 pass3 warn0 fail83A
| Signal | Points | Findings | Rationale | |
|---|---|---|---|---|
| pass | Machine-readable errors (RFC 9457)via docs | 28/28 | Documents 21 distinct 4xx/5xx error response codes, so an agent can branch on specific failures instead of guessing. Investigated: docs 100%, sdk 100%, spec 50%, cli 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 (367 of 377) have both a clear summary and a descriptive name, so an agent can pick the right endpoint. Investigated: spec 100%, sdk 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 | 13.4/22 | 20 of 50 pages have substantive content differences between markdown and HTML (avg 30% missing). Investigated: docs 61%. | Server-rendered, clean, small-footprint docs are what an agent can cheaply fetch and parse correctly. |
| pass | Docs structured datavia docs | 8/8 | Machine-readable JSON-LD Article markup on 12 of 20 assessed pages (60%), 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 | Agent instructions file (AGENTS.md)via sdk | 5/10 | No agents.md or skill.md context file found (nice-to-have for agent operation). Investigated: sdk 50%, cli 0%, 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. |
| warn | Description consistency across surfaces | 1/7 | Mean pairwise description similarity across 3 surfaces (spec, docs, sdk) is 5% (threshold 35% for full credit). | Every surface tells the same story about what the product is. |
Agent UsabilityAgents have the context to use your APIs reliably, not just find them5 pass0 warn0 fail100A+
| Signal | Points | Findings | Rationale | |
|---|---|---|---|---|
| pass | Idempotency documentedvia sdk | 27/27 | Built-in retry machinery is present (grep-derived). Investigated: sdk 100%, spec 0%, docs 0%, cli 0%. | Documented idempotency lets agents retry safely. |
| pass | Rate-limit signalingvia spec | 22/22 | rate-limit behavior is documented on the docs site at https://vercel.com/docs/limits, even though it isn't declared in the API spec. Investigated: spec 100%, docs 100%. | Machine-readable rate-limit headers let agents throttle adaptively. |
| pass | Pagination documented & consistentvia spec | 22/22 | Pagination parameters are present on the 16 list endpoint(s), so an agent can page through results. Investigated: spec 100%, docs 100%, sdk 20%. | Consistent, documented pagination lets agents traverse collections. |
| pass | Sandbox separationvia spec | 20/20 | sandbox is documented on the docs site at https://vercel.com/docs/sandbox, even though it isn't declared in the API spec. Investigated: spec 100%, docs 100%, sdk 100%. | An isolated environment lets agents exercise destructive operations safely. |
| pass | Runnable collection with test scriptsvia sdk | 9/9 | README is present and includes a runnable quickstart. Investigated: sdk 100%, platform 0%. | A public, maintained collection with assertions is runnable truth agents validate against. |
Resources Discovered
The public resources we found for Vercel — the evidence behind the score. All discovered from public sources; nothing here requires access to your systems.
| Agent hints | Context7 (14,255) |
|---|---|
| APIs analyzed | 1 — Vercel API |