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Head to head · Analytics experiments · October 2026 research run

GrowthBook vs PostHog

GrowthBook scores 70.1 (BB) on agent readiness against PostHog's 68.4 (B), and leads in 1 of 7 scored categories. PostHog leads on schema & documentation, security & auth and transparency & trust. Both do analytics experiments.

GrowthBookGrowthBook, Inc. · HTTP API BB70.1/100#155 of 842 PostHogPostHog Inc. · HTTP API B68.4/100#204 of 842

Which one, for what

GrowthBook BB

Good for Teams that want flags and experiments analysed against their own warehouse, with an open-source core and a self-hosted option.

Ahead on

  • Reliability, 86 against 74

Also in its favour

  • Agent-ready, a grade of BB or better
  • Runs on your own machine

Watch for

The API tools take a path and a JSON string and don't validate payloads, so correct calls depend on the bundled skills

PostHog B

Good for An agent that answers product questions in SQL or with funnel, retention and trends queries, and that manages feature flags, experiments and error tracking in the same project.

Ahead on

  • Schema & documentation, 81 against 76
  • Security & auth, 84 against 68
  • Transparency & trust, 83 against 74

Watch for

31 incidents on the status page between 9 July and 6 October 2026, four of them analytics query timeouts or failures

Score by category

CategoryWeight this runGrowthBookPostHogEdge
Reliability16%208674GrowthBook +12
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.27681PostHog +5
Agent ergonomics13%16.27678PostHog +2
Security & auth14%17.56884PostHog +16
Payments & pricing10%12.54040even
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.88989even
Transparency & trust7%8.87483PostHog +9
Negative events≤15-3-7
Total70.1 · BB68.4 · B

Facts side by side

FactGrowthBookPostHog
KindHTTP APIHTTP API
VendorGrowthBook, Inc.PostHog Inc.
Hosted endpointhttps://mcp.growthbook.io/mcphttps://us.posthog.com
TransportsHTTP, Streamable HTTP, stdioHTTP, Streamable HTTP
AuthOAuth or keyOAuth or key
PricingFreemiumFreemium
x402nono
LicenceMIT for the core and for the MCP server. Three enterprise directories in the main repository are under GrowthBook's enterprise licence. GrowthBook Cloud is a hosted service under the Customer AgreementMIT for the repository outside the ee directory, which has its own licence. PostHog Cloud is a hosted service under PostHog's terms
Tools exposed41096
Read-only variant documentednoyes
llms.txtyesyes
MCP registryio.github.growthbook/growthbook-mcpio.github.PostHog/mcp
Last release2026-10-062026-10-05
Terms last updated2025-06-192026-06-29
Privacy policy last updated2026-06-082026-06-29
Customer content may train modelsyesyes, with an opt-out
Terms restrict automated accessnot found in the textnot found in the text
Terms restrict benchmarkingyesyes
Terms or service can change without noticenot found in the textnot found in the text
Arbitration or class-action waivernot found in the textnot found in the text
Popularity8.5k stars, 1.3M npm/wk, 433k PyPI/wk40k stars, 15.2M npm/wk

Verdicts

GrowthBook

GrowthBook Cloud's MCP server has four tools with read and write annotations, OAuth with dynamic client registration, and a 414-operation OpenAPI spec behind it. The free plan needs no card. The API tools pass paths and JSON bodies through without validation, every key is limited to 60 requests a minute, and audit logs are Enterprise only.

PostHog

PostHog suits agents that need to query product data and manage flags or experiments. Its hosted MCP server has OAuth scopes, a read-only mode and a one-tool CLI mode over 1,096 tools. The status page shows 31 incidents in 90 days, four on analytics queries, and three security incidents were disclosed in the last year.

Before you call either

GrowthBook

  1. Connect to https://mcp.growthbook.io/mcp and complete OAuth in a browser. Use https://mcp.growthbook.io/mcp/api for the two API tools alone
  2. Call growthbook_list_skills and growthbook_read_skill before writing. The API tools don't validate payloads, so use the paths the skill names
  3. Stay under 60 requests a minute per key. On 429 wait for the RateLimit-Reset seconds before retrying
  4. List calls return 10 items by default. Pass limit up to 100 and offset to page
  5. A 422 is a soft warning. Resubmit with ?ignoreWarnings=true only after reading the message

PostHog

  1. Add ?readonly=true or the x-posthog-read-only header to the MCP URL unless the task needs writes
  2. Pin the session with x-posthog-project-id, which also removes the switch-project and switch-organization tools
  3. In CLI mode run info <tool> once before call, and send one exec command per request
  4. On a 429 with code api_queries_budget_exceeded, wait for Retry-After and read X-PostHog-Query-Budget-Remaining-Bytes
  5. Page SQL results by keyset on timestamp. OFFSET returns 400 for personal API keys, and results cap at 50,000 rows

Questions

Which is better for AI agents, GrowthBook or PostHog?

GrowthBook scores 70.1 (BB) on agent readiness against PostHog's 68.4 (B), and leads in 1 of 7 scored categories. PostHog leads on schema & documentation, security & auth and transparency & trust.

Do GrowthBook and PostHog need an API key?

Both take an API key or an OAuth sign-in.

Can an agent call GrowthBook and PostHog without installing anything?

Yes. GrowthBook has a hosted endpoint at https://mcp.growthbook.io/mcp and PostHog at https://us.posthog.com.

Are GrowthBook and PostHog open source?

Yes. GrowthBook is open source (MIT for the core and for the MCP server. Three enterprise directories in the main repository are under GrowthBook's enterprise licence. GrowthBook Cloud is a hosted service under the Customer Agreement). PostHog is open source (MIT for the repository outside the `ee` directory, which has its own licence. PostHog Cloud is a hosted service under PostHog's terms).

Other comparisons with GrowthBook or PostHog

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