FullContact vs ZeroBounce

FullContact 20

The MCP quickstart and authentication pages were published on 30 April 2026, between 90 and 180 days ago, and the errors page was edited on 15 September 2026 (10). No dated releases or changelog entries in the last 90 days (0). A support address and request IDs, with a changelog that stops in 2022 (5 of 15). The Python client was last released in July 2022 and the MCP server isn't in the official registry (3 of 15). No current package or CI to judge (2 of 10).

ZeroBounce 70

Closed service. The JavaScript SDK 3.0.0 was published on 25 October 2026 (30). No API changelog; the dated changes found in 90 days are that release and status-page notices, fewer than three releases (10 of 20). Support by email and 24/7 chat per the docs, a public status page; replies not tested (10 of 15). Official SDKs in many languages and an MCP server (15). Package health not checked (5 of 10). 30+10+10+15+5 = 70.

FullContact 10

No x402, MPP or L402 (0). No prices published. The pricing page asks visitors to talk to an expert (0). A free Platform account and sandbox keys for evaluation, but whether production lookups need a contract or a card wasn't stated (10 of 20). A person signs up in a browser and generates a key (0).

ZeroBounce 35

No x402, MPP or L402 (0). Per-credit prices public, from $39 for 2,000 validations (20). Freemium of 100 validations a month for business or premium domains; a card requirement isn't stated, and free webmail addresses don't qualify (15 of 20). A person signs up in a browser (0). 0+20+15+0 = 35.

FullContact 43

One Bearer API key per integration, revocable with a rotation procedure, scoped by product entitlement rather than by scope. No OAuth on the MCP server (20). Every call is a read and nothing writes, but there is no read-only key mode beyond entitlements (12 of 20). Responses carry bios and social data from third parties, and no prompt-injection guidance was found (3 of 15). Every MCP response carries a request_id, and no per-call log for the customer was found (3 of 15). The MCP docs say the server runs inside FullContact's SOC 2 boundary, but the security page, dated 1 January 2020, lists no certification or reporting channel, and there is no security.txt (5 of 20).

ZeroBounce 65

Several named keys besides a Master key, regeneration, deactivation and IP whitelists (25), less 10 because the documented calls carry the key in the api_key query string (15 of 30). Validation only reads, though file and list endpoints can delete uploads (12 of 20). Results are structured status codes with little free text (10 of 15). API usage and dashboard statistics endpoints (10 of 15). SOC 2 Type 2, ISO/IEC 27001:2022, continuous testing with Intigriti and penetration testing with BitSentinel; no public disclosure policy found (18 of 20). 15+12+10+10+18 = 65.

FullContact 70

No OpenAPI for the REST API was found, and docs.fullcontact.com/reference returned 404. The MCP tool has a typed JSON Schema for its inputs (20 of 25). llms.txt and Markdown copies of every page (10). The tool description says what it does but not when to use it, and the docs explain which identifier combinations match best (13 of 20). Typed inputs, but no required fields or enums, and the rule that location needs a name is only in text (8 of 15). Examples for every input combination and an error table with codes, HTTP analogues and a retryable flag (14 of 15). v3 in the path and a changelog whose newest entries date from 2022 and earlier, while the MCP docs went up in 2026 without a changelog entry (5 of 15).

ZeroBounce 54

No OpenAPI or other machine-readable contract found; a Postman collection is linked (5 of 25). llms.txt lists marketing pages, and the docs have no Markdown twins (5 of 10). Endpoint pages explain timing, credits and when to use batch or file APIs (14 of 20). Parameter tables and listed status and sub-status values, including the ai_agent_mailbox sub-status added in July 2026 (10 of 15). Examples per endpoint, a sandbox and an error-code page (12 of 15). v2 paths, an API migration page and dated maintenance notices on the status page, with no API changelog (8 of 15). 5+5+14+10+12+8 = 54.

FullContact 62

Graded with the hosted lines on the MCP server and the REST API behind it. A public status page at status.fullcontact.com on Pulsetic (20). It renders with JavaScript, so components and history weren't readable (5). A default limit of 6,000 queries a minute is published (15). The MCP server returns rate_limit_exceeded with retry_after_seconds and marks retryable codes, and the REST API delays rather than rejects requests over the limit. All calls are lookups, so retries are safe (12 of 15). No SLA found (0). The MCP server reports version 1.0.0 and the API is v3, neither labelled beta (10).

ZeroBounce 75

Hosted lines. Statuspage at status.zerobounce.net with API, API-US, API-EU, Bulk API, website and Cloudflare components (20). The incident feed for 8 August to 6 November shows a 6-minute members platform disruption on 9 September, about 3 minutes of reduced EU API availability on 1 October, and a file upload issue on 26 October resolved within 6 minutes, all minor (20). Limits published per endpoint group with numbers and block lengths (15). 429 is documented with advice to throttle, but no Retry-After, and a block can last an hour or a day (10 of 15). No SLA found (0). Generally available (10). 20+20+15+10+0+10 = 75.

FullContact 75

One tool, so the context cost is small (25). No paging is needed for single lookups, the response is a normalised profile, and Insight Bundles are fixed per account rather than per call (10 of 20). Stable error codes with retryable flags, request IDs and retry_after_seconds, and not_found documented as a normal miss (20). Lookups are safe to retry, but the tool carries no readOnlyHint, and misses are billed as calls (10 of 20). One identifier is enough, but the Python client was last released in July 2022 (10 of 15).

ZeroBounce 69

A compact JSON result per address, batch validation and a file API for lists (18 of 25). Little to paginate; file status and results by file id (10 of 20). Status and sub-status codes say why an address failed, and the error page explains 400, 404 and 429 (14 of 20). Unknown results are free and safe to retry; repeated validations are charged again (12 of 20). Many official SDK wrappers and an MCP server, with few required parameters (15). 18+10+14+12+15 = 69.