# Countly vs GrowthBook

> GrowthBook scores 70.1 (BB) on agent readiness against Countly's 54.8 (C), and leads in every scored category. Both do analytics query. Category scores, facts, verdicts and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/countly-vs-growthbook
- Markdown: https://www.anchorterminal.com/compare/countly-vs-growthbook.md (~2,500 tokens)
- Slim: https://www.anchorterminal.com/compare/countly-vs-growthbook.min.md (~780 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/countly-vs-growthbook.json (this page as data, same URL with Accept: application/json)
- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- Updated: 2026-10-09

GrowthBook scores 70.1 (BB) on agent readiness against Countly's 54.8 (C), and leads in every scored category. Both do analytics query.

- Countly: grade C, 54.8/100, rank #607 of 842. Markdown https://www.anchorterminal.com/tools/countly.md · JSON https://www.anchorterminal.com/api/v1/tools/countly.json
- GrowthBook: grade BB, 70.1/100, rank #155 of 842. Markdown https://www.anchorterminal.com/tools/growthbook.md · JSON https://www.anchorterminal.com/api/v1/tools/growthbook.json

## Which one, for what

### Countly (C)

Good for: An agent whose owner runs Countly on its own infrastructure or a dedicated Flex server and wants analytics, crash and remote-config data through MCP with per-category permissions.

Also in its favour:
- No incidents deducted, where GrowthBook loses 3 points for them

Watch for: No public status page or incident history was found for Flex servers or for mcp.count.ly

### 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 28
- Agent ergonomics, 76 against 66
- Security & auth, 68 against 63
- Payments & pricing, 40 against 17
- Maintenance & community, 89 against 80

Also in its favour:
- Agent-ready, a grade of BB or better
- Free to start without a card

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


## Score by category

| Category | Weight | Countly | GrowthBook | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 28 | 86 | GrowthBook +58 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 75 | 76 | GrowthBook +1 |
| Agent ergonomics | 13% (16.2 this run) | 66 | 76 | GrowthBook +10 |
| Security & auth | 14% (17.5 this run) | 63 | 68 | GrowthBook +5 |
| Payments & pricing | 10% (12.5 this run) | 17 | 40 | GrowthBook +23 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 80 | 89 | GrowthBook +9 |
| Transparency & trust | 7% (8.8 this run) | 70 | 74 | GrowthBook +4 |
| Negative events | ≤15 | 0 | -3 | |
| **Total** | | **54.8 · C** | **70.1 · BB** | |

## Facts side by side

| Fact | Countly | GrowthBook |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Countly Ltd | GrowthBook, Inc. |
| Hosted endpoint | `https://mcp.count.ly/mcp` | `https://mcp.growthbook.io/mcp` |
| Transports | HTTP, stdio, Streamable HTTP | HTTP, Streamable HTTP, stdio |
| Auth | API key | OAuth or key |
| Pricing | Paid | Freemium |
| x402 | no | no |
| Licence | Countly Lite is AGPL-3.0 with added branding terms under Section 7. Enterprise plugins are proprietary. Flex is a hosted service under Countly's terms. The MCP server is MIT | 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 |
| Tools exposed | 209 | 4 |
| Read-only variant documented | yes | no |
| llms.txt | yes | yes |
| MCP registry | not listed | `io.github.growthbook/growthbook-mcp` |
| Last release | 2026-10-07 | 2026-10-06 |
| Terms last updated | 2026-09-25 | 2025-06-19 |
| Privacy policy last updated | 2026-09-25 | 2026-06-08 |
| Customer content may train models | not found in the text | yes |
| Terms restrict automated access | not found in the text | not found in the text |
| Terms restrict benchmarking | not found in the text | yes |
| Terms or service can change without notice | yes | not found in the text |
| Arbitration or class-action waiver | not found in the text | not found in the text |
| Popularity | 28k npm/wk | 8.5k stars, 1.3M npm/wk, 433k PyPI/wk |

## Verdicts

**Countly.** Countly suits an agent working against a server its owner already runs. The official MCP server filters its 209 tools by edition, plugin and permission and has per-category read-only settings. No status page, OpenAPI document or published API rate limit was found, and the Flex trial needs a credit card.

**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.

## Before you call either

### Countly

1. Create a dedicated token in the Token Manager, limited to the apps and endpoints the task needs, and send it in the `countly-token` header, not the URL
2. Set `COUNTLY_TOOLS_ALL=R` unless the task needs writes. The token's own permissions still apply and the stricter of the two wins
3. Call `apps_list` first. Most tools need `app_id` or an exact `app_name`
4. Check `get_version` for the detected edition before planning funnel, retention or cohort queries, which need Enterprise plugins
5. Set `ENABLE_ANALYTICS=false` to stop usage reports to stats.count.ly, and prefer the stdio server to mcp.count.ly so the server URL and token stay local

### 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

## Questions

### Which is better for AI agents, Countly or GrowthBook?

GrowthBook scores 70.1 (BB) on agent readiness against Countly's 54.8 (C), and leads in every scored category.

### Do Countly and GrowthBook need an API key?

Countly needs an API key. GrowthBook takes an API key or an OAuth sign-in.

### Can an agent call Countly and GrowthBook without installing anything?

Yes. Countly has a hosted endpoint at https://mcp.count.ly/mcp and GrowthBook at https://mcp.growthbook.io/mcp.

### Are Countly and GrowthBook open source?

Yes. Countly is open source (Countly Lite is AGPL-3.0 with added branding terms under Section 7. Enterprise plugins are proprietary. Flex is a hosted service under Countly's terms. The MCP server is MIT). 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).


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/countly-vs-growthbook.json, and with the fewest tokens: https://www.anchorterminal.com/compare/countly-vs-growthbook.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "countly", "b": "growthbook"}`. From a terminal: `anchor compare countly growthbook`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/countly.json and https://www.anchorterminal.com/api/v1/tools/growthbook.json

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- [Countly vs Statsig](https://www.anchorterminal.com/compare/countly-vs-statsig.md)
- [Countly vs Woopra](https://www.anchorterminal.com/compare/countly-vs-woopra.md)
- [Fullstory vs GrowthBook](https://www.anchorterminal.com/compare/fullstory-vs-growthbook.md)
- [GrowthBook vs Pendo](https://www.anchorterminal.com/compare/growthbook-vs-pendo.md)
- [GrowthBook vs Woopra](https://www.anchorterminal.com/compare/growthbook-vs-woopra.md)
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- [GrowthBook vs LaunchDarkly](https://www.anchorterminal.com/compare/growthbook-vs-launchdarkly.md)
- [GrowthBook vs Mixpanel](https://www.anchorterminal.com/compare/growthbook-vs-mixpanel.md)
- [GrowthBook vs Optimizely Experimentation](https://www.anchorterminal.com/compare/growthbook-vs-optimizely.md)
- [GrowthBook vs PostHog](https://www.anchorterminal.com/compare/growthbook-vs-posthog.md)
- [GrowthBook vs Statsig](https://www.anchorterminal.com/compare/growthbook-vs-statsig.md)
- [Countly vs LaunchDarkly](https://www.anchorterminal.com/compare/countly-vs-launchdarkly.md)