Mostly Good Metrics vs PostHog

Mostly Good Metrics 29

Graded on the hosted service with the hosted lines. No status page was found (0) and no incident history could be read (5). Ingestion limits are documented per plan (1,000 to 100,000 events a minute and 10,000 to 1,000,000 an hour), but no limit for MCP or query calls was found (12 of 15). 429 with Retry-After in the header and body, and the SDKs queue events and back off. No idempotency or safe-retry guidance for writes (12 of 15). No SLA (0). The press kit calls the product a public beta (0). 0+5+12+12+0+0 = 29.

PostHog 84

Graded on PostHog Cloud with the hosted lines. Status page on incident.io at posthogstatus.com with per-region components, among them MCP Server and REST API Query endpoints (20). Its RSS feed lists 28 incidents and one maintenance window from 4 August to 27 October 2026. Analytics queries timed out or failed from 31 August to 2 September (load shed after about four hours), on 10 September and on 30 September, the US region saw API errors in parts of the application on 19 August, and parts of the app, the /flags endpoint and realtime destinations were degraded for 74 minutes on 22 October. Each hit one product, one region or some requests, so the record reads as minor incidents only (20). Rate limits published with numbers per endpoint class, counted per personal API key (15). The query read budget answers 429 with Retry-After and budget headers, but there is no backoff guidance for the general limits and no idempotency keys for writes were found (9). 99.95 per cent uptime SLA in the terms for the Enterprise package (10). The REST API is generally available and the MCP docs carry no beta label (10).

Mostly Good Metrics 33

OAuth 2.0 with PKCE, dynamic client registration and a revocation endpoint for MCP and the CLI; project ingest keys in a Bearer header that can be pinned to origins or app IDs. The only tool scope advertised is mcp:tools, so a connection gets every tool the user can use (24 of 30). Restricted keys and a confirmation step for unrestricted keys in the CLI; no read-only MCP mode or approval for deletes was found (6 of 20). Event properties come from apps and end users and reach the agent, and no prompt-injection guidance was found (3 of 15). No audit log was found (0). No security.txt, disclosure policy or certification was found (0). 24+6+3+0+0 = 33.

PostHog 84

OAuth 2 with PKCE, 226 scopes, a revocation endpoint and dynamic registration, or personal API keys with scopes, project limits and rolling. A key can still be created with full access, and keys found in public GitHub repositories are rolled automatically (28). Read-only mode, filters by product area or tool, project pinning, and a typed confirmation for 18 admin actions (18). The MCP docs warn about prompt injection and tell users to review tool calls, and the CLI escapes informational responses. No further mitigation is documented for event and replay data that end users wrote (9). Activity logs with an API, MCP calls recorded with the caller's IP, and an admin view of every key with last use. Longer retention needs a platform package (12). security.txt valid to 30 August 2027, Bugcrowd disclosure programme paid in merchandise, public SOC 2 Type 2 report, annual penetration test and a public advisories page (17).

Mostly Good Metrics 45

The service is closed; the SDKs and CLI are MIT. Terms of December 2025 with no legal entity named (18 of 30). The privacy policy and terms agree on raw-event retention for the subscription's life and deletion within 14 days of account deletion; the about page says data is not used to train models. No DPA was found (18 of 30). The legacy X-MGM-Key header is still supported, and no deprecation policy was found (3 of 20). The terms name eight sub-processors with their purpose, without data locations (12 of 20). 18+18+3+12 = 51.

PostHog 83

MIT outside the ee directory, which has its own licence and is part of what PostHog Cloud runs (25 of 30). Privacy policy, a self-serve DPA and the terms agree. The terms let PostHog use de-identified customer content to train its own models unless the customer opts out, and bar third parties from training on it. The privacy policy gives no retention periods, while the pricing page gives 1 year on the free plan and 7 on paid (22). No deprecation policy was found, and the query docs reserve the right to restrict export-like queries without notice. 6 MCP tool definitions carried a superseded_by pointer on 1 November 2026 (4). Sub-processor list updated 12 June 2026 with locations, 14 days' notice of changes, and data in Virginia or Germany (20).

Mostly Good Metrics 49

No OpenAPI file was found. The docs say every MCP tool describes its own parameters, and the query definition object is documented in full; we didn't open an MCP session to read the schemas (12 of 25). No llms.txt (404) and no Markdown pages served for agents (0). Each tool area is documented with examples, and the docs say when to use query_metrics instead of repeated execute_query calls (10 of 20). The query definition lists metrics, dimensions, date ranges and filter operators (9 of 15). The ingestion API documents its error body and status codes, and query_metrics reports per-item errors (11 of 15). /v1 and /api/v2 paths and dated SDK tags, but no product changelog (7 of 15). 12+0+10+9+11+7 = 49.

PostHog 81

OpenAPI 3.1 served without a login, 1,742 paths and 2,347 operations, and typed JSON Schema inputs on the MCP tools (25). llms.txt, and every docs page has a Markdown copy at the same address with .md (10). 1,487 of 2,347 operations (63 per cent) have a description. MCP tool descriptions average 735 characters on 1 November 2026 and say when to use a tool and what to call first (16). 1,243 enums across 4,792 schemas and a required scope on most operations (13). 706 examples in the spec. It documents 400 on 224 operations and 429 on 55, and the docs show the error shape with examples (9). Dated public changelog with RSS, but the spec version is fixed at 1.0.0 and the API has no versions (8).

Mostly Good Metrics 49

53 tools, more than 30 (5). We added 3 because Goals and Alerts tools load only where enabled and query_metrics batches up to 10 queries (8 of 25). Date ranges, grouping and filters on queries; no documented page or limit parameters for lists (12 of 20). JSON errors with a message, and per-item status in batch results (13 of 20). Annotations weren't readable without a session, the tool list includes deletes and key revocation, and no idempotency keys were found (4 of 20). Five client SDKs and a CLI with --json output (12 of 15). 8+12+13+4+12 = 49.

PostHog 78

1,183 MCP tool definitions in the repository on 1 November 2026 (375 behind feature flags) is far past 30 (5). Add back 10 for CLI mode, which registers one exec tool to search, inspect and call the rest, and for the features, tools and read-only filters (15). Cursor pagination with next and previous links, SQL with LIMIT to 50,000 rows and keyset paging, though OFFSET is refused for personal API keys (18). Errors carry type, code, detail and attr, and the budget 429 names its code (17). Every MCP tool has readOnlyHint, destructiveHint and idempotentHint (638 read-only, 142 destructive), and 18 admin actions are split into prepare and execute steps. No idempotency keys on REST writes (15). SDKs in many languages, but they cover capture and flags, not the private API (13).

Mostly Good Metrics 74

CLI v0.1.4 was tagged on 16 October 2026 (30). The JavaScript SDK released 0.12.0, 0.13.0 and 0.13.1 between 5 September and 2 October, and the Swift SDK 1.0.0 and 1.0.1 on 2 October (20). A closed service with no public changelog, support by email and GitHub repositories for the SDKs; issue activity wasn't read because the GitHub API refused us for its rate limit (6 of 25). Not in the official MCP registry; official SDKs in five languages are current (10 of 15). CI workflows on the SDK and CLI repositories (8 of 10). 30+20+6+10+8 = 74.

PostHog 89

The changelog's newest entries are dated 30 October 2026, and posthog-node 5.61.1 and the Python SDK's posthog-v7.81.1 came out the same day (30). 204 dated changelog entries since 3 August 2026 (20). Public changelog, community questions and in-app support. Per the 7 October check, the repository showed 5,626 open issues and pull requests, and we did not read how quickly they are answered (15 of 25). io.github.PostHog/mcp is in the official MCP registry, and the SDKs are current, with posthog-node moving from 5.55.0 to 5.61.1 between 7 and 30 October 2026 (15). 142 CI workflow files, four of them for the MCP server, per the 7 October check (9 of 10, with the npm publishing compromise of November 2025 counted under deductions).