Capitalonecapitalone.com
Capital One's API program shows strength in discovery reachability and crawlability, but faces critical gaps in two areas that directly block partner and agent productivity: the API contract lacks concrete examples agents can build against, and there is no runnable, test-backed collection partners can execute to validate integrations. Closing these gaps — alongside adding agent-readable instruction files, structured documentation data, and in-doc code samples — will dramatically shorten the time partners and their AI agents spend guessing at behavior and dramatically increase integration success rates.
API DesignA clean, typed, well-governed API contract agents can reason about0 pass1 warn1 fail50D
| Signal | Points | Findings | Rationale | |
|---|---|---|---|---|
| warn | Security & governance hygienevia wellknown | 7.5/15 | security.txt present but served only at the legacy /security.txt path; missing or expired Expires. Investigated: wellknown 50%. | No leaked secrets, no critical lint violations, no OWASP API Top-10 spec smells, and a published vulnerability-disclosure channel. |
| fail | Example coveragevia docs | 0/10 | No detectable code samples across 20 sampled docs pages. Investigated: docs 0%. | Examples carry shape semantics schemas under-specify — for humans and agents alike. |
| na | Machine-readable, versioned contract | —/25 | No surface produced evidence for this capability in this run. | A current OpenAPI version with a declared versioning scheme lets agents reason about the contract. |
| na | Schema coverage & depth | —/25 | No surface produced evidence for this capability in this run. | Typed, complete request/response schemas are what make agent function-calling possible. |
| na | Auth declared & discoverable | —/25 | No surface produced evidence for this capability in this run. | Agents can only authenticate when auth is declared, scoped, and discoverable. |
Developer ExperienceThe context both developers and agents need to integrate fast — onboarding, code samples, complete descriptions and worked examples1 pass1 warn1 fail66C
| Signal | Points | Findings | Rationale | |
|---|---|---|---|---|
| pass | Self-service developer portalvia docs | 29/29 | Self-service signup at https://verified.capitalone.com/enroll/pii?external_id=MS_ISL_DigEnroll; no free tier or sandbox language detected. Investigated: docs 100%. | Self-serve key/account creation is the fast first call for partners, with no sales gate. |
| warn | Quickstart presentvia docs | 12.5/25 | Quickstart page reachable (12 variants scanned starting at https://developer.capitalone.com/quickstart) but no runnable code sample detected in HTML or .md variant. Investigated: docs 50%. | A quickstart is the fastest path from landing page to first successful call. |
| fail | Code samples in docsvia docs | 0/18 | No detectable code samples across 20 sampled docs pages. Investigated: docs 0%. | Multi-language samples shorten time-to-first-call. |
| na | Description completeness | —/15 | No surface produced evidence for this capability in this run. | Complete descriptions are the context humans and agents need to use endpoints. |
| na | Changelog published | —/13 | No surface produced evidence for this capability in this run. | A published changelog lets partners track changes without surprise. |
Agent DiscoveryPartners and their agents can find your APIs — llms.txt, registries, crawlable and reachable docs1 pass3 warn0 fail69C
| Signal | Points | Findings | Rationale | |
|---|---|---|---|---|
| pass | Registry & SDK presencevia docs | 28/28 | Indexed on Context7 (capitalone/dataprofiler, 743 snippets). Investigated: docs 100%, sdk 100%, cli 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 | 34 of 34 pages return 200 for non-existent URLs (soft 404). Investigated: docs 50%. | 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 | 10/30 | No llms.txt found at any candidate location (https://developer.capitalone.com/llms.txt, https://developer.capitalone.com/docs/llms.txt). Investigated: docs 33%. | A valid, comprehensive llms.txt is the machine-readable entry point for agents. |
| warn | Crawlable / AEOvia wellknown | 9/12 | Sitemap present (34 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 docs0 pass1 warn2 fail51D
| Signal | Points | Findings | Rationale | |
|---|---|---|---|---|
| warn | Agent-navigable, token-efficient docsvia docs | 12.6/22 | No pages support .md URLs (0/34 tested). Investigated: docs 57%. | Server-rendered, clean, small-footprint docs are what an agent can cheaply fetch and parse correctly. |
| 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 20 sampled pages — likely a CSR-only docs site. 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. |
| na | Machine-readable errors (RFC 9457) | —/28 | No surface produced evidence for this capability in this run. | RFC 9457 problem details and a documented error-code inventory let agents parse failures without burning tokens. |
| na | Operation purpose clarity | —/25 | No surface produced evidence for this capability in this run. | Agents select the right endpoint from its summary + operationId; clear, named operations make tool-selection reliable — the strongest driver of correct tool choice. |
| na | Description consistency across surfaces | —/7 | Only 0 surface description(s) with ≥6 tokens available; need at least 2 to compare. | Every surface tells the same story about what the product is. |
Agent UsabilityAgents have the context to use your APIs reliably, not just find them0 pass0 warn1 fail40F
| Signal | Points | Findings | Rationale | |
|---|---|---|---|---|
| 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 | Idempotency documented | —/27 | No surface produced evidence for this capability in this run. | Documented idempotency lets agents retry safely. |
| na | Rate-limit signaling | —/22 | No surface produced evidence for this capability in this run. | 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. |
| na | Sandbox separation | —/20 | No surface produced evidence for this capability in this run. | An isolated environment lets agents exercise destructive operations safely. |
Resources Discovered
The public resources we found for Capitalone — the evidence behind the score. All discovered from public sources; nothing here requires access to your systems.
| Agent hints | Context7 (743) |
|---|