Apollo API + MCP vs ZeroBounce

Apollo API + MCP 87

OpenAPI 3.1.0 file at docs.apollo.io/openapi/apollo-rest-api.json with 83 operations on 77 paths, last modified 30 October 2026 (25). llms.txt with 107 links in 16 sections and Markdown twins of every page (10). Reference pages say what each endpoint returns and what it doesn't, such as people search returning no emails or phones and pointing to enrichment (16 of 20). Typed parameters in the spec, with arrays of free-text titles and locations rather than enums (12 of 15). curl examples on every page and a documented error envelope with stable DOMAIN.CATEGORY.REASON codes and remediation suggestions (14 of 15). Public changelog, but it still holds a single entry, dated 2026-09-18, and the API has no version scheme beyond v1 (10 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.

Apollo API + MCP 58

Newest dated release is Apollo CLI v2.2.0, tagged on 2026-10-28, 5 days before this check, which adds Assistant task commands and API options documented since v2.0.0 (30). The API changelog's only entry, structured API errors, is dated 2026-09-18. In the last 90 days that entry and the CLI tag (counted half) make 1.5 dated changes, short of three. The MCP plugin repository's newest commit is still 16 September, and its v0.1.1 tag and the registry entries are unchanged since July (0). Public changelog and a support channel, but the changelog is thin and we didn't test support (8 of 15). Listed in the official MCP registry as io.github.apolloio/apollo-mcp, a GitHub-verified namespace, version 0.1.1 published 2026-07-20 (15). No SDK packages to judge. The plugin repository has a registry publish workflow (5 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.

Apollo API + MCP 73

Closed service with published terms naming ZenLeads Inc. d/b/a Apollo.io. The MCP plugin repo is MIT (15). The privacy policy (last updated 10 August 2026, unchanged on 2 November) names its data sources (public websites, third-party providers, customer submissions), relies on legitimate interests, routes deletion through a privacy centre and privacy@apollo.io, and links a DPA. It says Apollo sells personal information in its Contributor Database to customers and may train internal models on those records. Retention is 'consistent with the purposes', with no periods (22 of 30). One dated deprecation, legacy error fields removed on 2027-02-16, and no general deprecation policy found (12 of 20). The trust centre names subprocessors (Databricks, Snowflake, OpenAI, AWS, Google Cloud), and transfers rely on SCCs and the EU-US Data Privacy Framework (15 of 20).

ZeroBounce 63

Closed service under terms naming Hertza L.L.C. (ZeroBounce) of Nevada; SDKs and MCP server open source (15 of 30). The data protection page says uploaded data is never kept more than 30 days, the privacy policy of 30 June 2026 keeps account data 'as long as needed', and EU and UK DPAs are published (22 of 30). An API migration page, with no dated deprecation policy (6 of 20). A sub-processor list naming each provider and the data exchanged (16 of 20). 15+22+6+16 = 59.

Apollo API + MCP 60

Keys sent in the x-api-key header. Scoped keys are the default and are limited to chosen endpoints (403 elsewhere), and keys can be regenerated or deleted. OAuth for the MCP in chat clients. Headless MCP use needs a master key that reaches every endpoint (25 of 30). Scoped keys give least privilege on REST. The MCP has 13 write actions, including sending one-off emails, adding contacts to sequences and buying domains and mailboxes, with no read-only mode, and approval is left to the client (10 of 20). Results include third-party-sourced profile text, emails and call transcripts, and we found no prompt-injection guidance (3 of 15). Usage stats endpoint, rate-limit usage headers, and audit logging listed in the trust centre (8 of 15). ISO 27001 and SOC 2 Type 2 per the SafeBase trust centre, disclosure by email to security@apollo.io, no bug bounty found, no security.txt (14 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.

Apollo API + MCP 30

No x402, MPP or L402 (0). Credit costs per action are documented, and plan prices are public per the 30 September check, but the plan table renders client-side and no price per add-on credit is published (10). Free plan with API rate limits listed in the docs. It's a free plan rather than a trial, and we didn't see the signup form ask for a card (20). A person signs up in a browser with a work email (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.