GrowthBook vs OpenPanel

GrowthBook 76

OAuth with PKCE, dynamic client registration, refresh tokens and a revocation endpoint for the hosted MCP server. Since October the consent page asks what the connection may do, Read only, Human-in-the-Loop, Full access or a custom base role limited by project or environment, so a token no longer has to carry the user's full permissions. Secret Keys take any built-in or custom role with per-project overrides, environment limits and expiry, Personal Access Tokens can be scoped below their user (7 October), and since 21 October keys and tokens rotate in place with a grace period for the old secret. Secrets travel in headers only (30). A Read Only option, an endpoint with the API tools alone, and read and write tools with annotations. Since 16 October Human-in-the-Loop holds risky or destructive REST writes, including those from the hosted MCP endpoint, until a person confirms them on a linked page, and each decision goes to the audit log. Human-in-the-Loop is an Enterprise preset, and on a plan with only the admin role, which includes Free, Full access is the only option (18 of 20). No guidance on prompt injection was found, though the tools return names and descriptions that people wrote (3 of 15). Audit logging, with export, is on Enterprise only. Personal tokens attribute actions to a user, Secret Keys can name the member behind a request with X-GrowthBook-Requested-By (13 October), and the MCP server labels its API calls with X-GB-MCP-* headers (10 of 15). SOC 2 Type II, a disclosure process with a form and SECURITY.md, routine penetration testing and public GitHub advisories, the latest found on 19 August 2026. Rewards are merchandise only and www.growthbook.io/.well-known/security.txt still answered 404 on 1 November (15 of 20). 30+18+3+10+15 = 76. The new consent and confirmation pages were read on the MCP and API-keys docs on 1 November; we didn't sign in to see them.

OpenPanel 41

Client credentials with three types (write, read for one project, root for the organisation), created and deleted in the dashboard (25), less 10 because the docs give ?token= in the MCP URL as an option (15 of 30). Read clients are read-only and limited to one project, and onboarding creates a read-only MCP client. No approval step for root-client writes (14 of 20). Tools return event properties, page titles and profile data sent from tracked sites, and no prompt-injection guidance was found (3 of 15). No audit log was found (0). SECURITY.md with a private advisory route and response times, a valid security.txt, and no bug bounty or certification found (9 of 20). 15+14+3+0+9 = 41.

GrowthBook 76

Four compact MCP tools, with skills loaded on demand and a /mcp/api endpoint that drops the skill tools (25). limit (default 10, maximum 100) and offset on 40 list operations, with filters by project, data source and status. No field selection was found, and the API tools return the raw response body (15 of 20). Errors are a status code and a message with no machine code. 422 marks a soft warning that can be resubmitted with ignoreWarnings, and the MCP server adds recovery hints for 401, 403, 404 and 429 (13 of 20). All four tools carry readOnlyHint and destructiveHint, and reads and writes are separate tools. Every write is marked destructive, and no idempotency keys were found (13 of 20). The API tools need one to three parameters. The SDKs cover flag evaluation in many languages, not the REST API (10 of 15). 25+15+13+13+10 = 76. Not re-read on 1 November beyond the MCP page and the spec, which still support each line.

OpenPanel 54

51 MCP tools, more than 30 (5). We added 3 because a read client doesn't get the 9 dashboard management tools (8 of 25). Insights endpoints take startDate, endDate, range, filters, cursor and limit (18 of 20). Errors aren't documented beyond 401 and 429 (12 of 20). No readOnlyHint or destructiveHint in the MCP source, no idempotency keys; delete_dashboard refuses a non-empty dashboard without forceDelete (3 of 20). Few required parameters, and SDKs for JavaScript, React, Next.js, Vue, React Native, Swift, Kotlin and Python (13 of 15). 8+18+12+3+13 = 54.

GrowthBook 86

Graded on GrowthBook Cloud with the hosted lines. Instatus page at status.growthbook.io with three components (GrowthBook Cloud App, Api, CDN) and a notice history (20). No notices from August to October 2026, and the newest entry in the feed, re-read on 1 November, is still dated 21 August 2025. The MCP server is not a listed component, and the 2.2.0 changelog fixes intermittent 502s in HTTP mode that were not posted, so 25 of 30. API keys are limited to 60 requests a minute on Cloud, re-read in the API introduction and the OpenAPI spec on 1 November; since 19 October self-hosted servers can set per-key limits (15). The docs say only to try again later on 429. The server source sends standard RateLimit headers and the MCP server waits for RateLimit-Reset and retries three times, but no backoff guidance or idempotency keys were found in the docs (8 of 15). The pricing page lists a 99.99 per cent uptime SLA on Enterprise, re-read on 1 November. The SLA document itself was not found in public (8 of 10). The REST API's /v1 is described as stable and the MCP docs carry no beta label (10). 20+25+15+8+8+10 = 86.

OpenPanel 70

Graded on OpenPanel Cloud with the hosted lines. OpenStatus page at status.openpanel.dev with API and Tracker components (20). In the 90 days from 8 August, one incident, degraded API performance for about two hours on 1 October 2026, caused by Hetzner private-network problems reaching the ClickHouse servers (15 of 30). Limits are documented with numbers for MCP (60 a minute per client) and the Export, Insights and Manage APIs (15). The docs say a 429 is returned and to back off exponentially; no Retry-After or idempotency guidance (10 of 15). No SLA was found (0). Generally available (10). 20+15+15+10+0+10 = 70.

GrowthBook 75

The core and the MCP server are MIT. Three enterprise directories in the main repository are under GrowthBook's enterprise licence and are part of what Cloud runs (25 of 30). A Customer Agreement, a Privacy Notice of 8 June 2026 and a DPA of 19 June 2025 are published. The agreement grants GrowthBook an unrestricted right to use Customer Data, including to train its AI algorithms, then limits personal information to performing the Services. The Privacy Notice gives no retention periods, and the docs say only aggregate results are stored. We did not read the DPA, which is a download (16 of 30). Legacy v1 routes and 34 operations are marked deprecated with no removal dates, and no deprecation policy was found. The MCP changelog gives migration steps (8 of 20). The sub-processor list of 11 May 2026 names seven providers with locations, mostly in the United States. Notice of new ones is promised only as far as the law requires (17 of 20). 25+16+8+17 = 66. The legal documents are per the 8 October check, not re-read on 1 November.

OpenPanel 83

AGPL-3.0 for the whole product, and the about page says there is no enterprise edition (30). Terms and privacy policy of 21 May 2026 agree, with a DPA published, transient IP use, data ownership kept by the customer, and providers named with locations. Retention periods are general rather than stated in days (22 of 30). No deprecation policy or dated notices found; v3.0.0 was a major release on 16 October 2026 (4 of 20). Sub-processors and data locations disclosed in the privacy policy (Hetzner, Germany) (18 of 20). 30+22+4+18 = 74.

GrowthBook 89

MCP server 2.2.0 is dated 5 October 2026 and published to the registry on 6 October, GrowthBook 5.1.0 was tagged on 21 September 2026, and the main repository's commit releasing the JavaScript and React SDKs 2.0.0 landed on 30 October (npm not readable from here) (30). In the 90 days from 3 August, GrowthBook 5.0.1 (19 August) and 5.1.0, MCP 2.1.0 (10 August) and 2.2.0, and the SDK 2.0.0 release commit (20). The main repository's 200 newest commits run from 5 to 30 October 2026, and there is a community Slack. We did not read how quickly issues are answered (15 of 25). io.github.growthbook/growthbook-mcp is in the official MCP registry at 2.2.0, published 6 October 2026 and still latest on 1 November (15). The MCP repository runs CI on Node 22 and 26 and took dependency updates on 8 and 27 October 2026, both still unreleased. The package states Node 18 or later, which CI does not test (9 of 10). 30+20+15+15+9 = 89.

OpenPanel 83

v3.30.0 was tagged on 6 November 2026 (30). 60 tagged releases between 8 August and 6 November (20). 572 commits since 8 August, a Discord server, a feedback board and email; issue response times weren't read because the GitHub API refused us for its rate limit (15 of 25). The official MCP registry has only a third-party OpenPanel server, not OpenPanel's own; official SDKs are current (10 of 15). Workflows build Docker images, SDKs and self-hosting releases; no test workflow was found in .github/workflows (8 of 10). 30+20+15+10+8 = 83.

GrowthBook 40

No x402, MPP or L402 (0). Prices are public without a login. Pro is $40 a seat a month, with $10 per million CDN requests, $1 per GB and $30 per million Managed Warehouse events above the allowance; the $40 seat and $30 per million were re-read on 1 November (20). The Starter plan is free with "No credit card required", re-read on 1 November (20). A person signs up in a browser, then approves OAuth or creates a key (0). 0+20+20+0 = 40.

OpenPanel 35

No x402, MPP or L402 (0). Public prices by event tier from $2.50 a month, with no overage charges; tiers rather than a per-event rate (15 of 20). 30-day free trial with no card, and free self-hosting (20). Signup is in a browser and client keys are created in the dashboard (0). 0+15+20+0 = 35.