Vercelvercel.com
Vercel's API program shows strong foundations in API design and discoverability, but two gaps are holding back partner and agent success. The most urgent is the absence of an agent instructions file, which means AI coding agents lack the structured context they need to work with your APIs without hallucinating or guessing.
API DesignA clean, typed, well-governed API contract agents can reason about3 pass2 warn0 fail94A+
| Signal | Points | Findings | Rationale | |
|---|---|---|---|---|
| pass | Auth declared & discoverablevia docs | 25/25 | authentication documented in the docs site at https://vercel.com/login?next=%2Fauthentication. 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 | 663/664 (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. |
| warn | Machine-readable, versioned contractvia spec | 18.8/25 | info.version="0.0.1" set but no versioning scheme (URL / header / media type) detected. Investigated: spec 75%, docs 50%, cli 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 100%. | 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 in 4 language(s) across docs (top: typescript, curl, python); 7/20 pages have ≥ 2 languages on the same page. Investigated: docs 100%, sdk 100%, spec 0%, 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 (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://vercel.com/docs/getting-started-with-vercel has a runnable sample in the .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 | Code samples in 4 language(s) across docs (top: typescript, curl, python); 7/20 pages have ≥ 2 languages on the same page. Investigated: docs 100%. | Multi-language samples shorten time-to-first-call. |
| pass | Description completenessvia spec | 15/15 | 82% description completeness (target 90%+). Investigated: spec 100%, sdk 96%. | Complete descriptions are the context humans and agents need to use endpoints. |
| pass | Changelog publishedvia spec | 13/13 | changelog documented in the docs site at https://vercel.com/changelog. 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, 16576 snippets). Investigated: docs 100%, cli 100%, mcp 100%, sdk 83%, 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 49 sampled pages; 1 failed to fetch. Investigated: docs 56%, sdk 0%. | A valid, comprehensive llms.txt is the machine-readable entry point for agents. |
| pass | Crawlable / AEOvia wellknown | 12/12 | Docs paths crawlable by all monitored AI agents. 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 pass2 warn1 fail79B
| Signal | Points | Findings | Rationale | |
|---|---|---|---|---|
| pass | Machine-readable errors (RFC 9457)via docs | 28/28 | 18 distinct 4xx/5xx response codes documented. 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 | 96% 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 | 13.4/22 | 19 of 49 pages have substantive content differences between markdown and HTML (avg 30% missing); 1 failed to fetch. 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 | JSON-LD Article markup on 12/20 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 | Description consistency across surfaces | 0.7/7 | Mean pairwise description similarity across 3 surfaces (spec, docs, sdk) is 3% (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 them4 pass0 warn1 fail92A+
| 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 documented in the docs site at https://vercel.com/docs/limits. Investigated: spec 100%, docs 100%. | Machine-readable rate-limit headers let agents throttle adaptively. |
| pass | Pagination documented & consistentvia spec | 22/22 | Pagination params detected on 17 list endpoint(s). Investigated: spec 100%, docs 100%, sdk 20%. | Consistent, documented pagination lets agents traverse collections. |
| pass | Sandbox separationvia spec | 20/20 | sandbox documented in the docs site at https://vercel.com/docs/sandbox. Investigated: spec 100%, docs 100%, sdk 100%. | An isolated environment lets agents exercise destructive operations safely. |
| 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. |
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 (16,576) |
|---|---|
| APIs analyzed | 1 — Vercel API |