# Flagsmith vs Fullstory (slim)

> Fullstory scores 63.3 (B) to Flagsmith's 61.2 (C) for event analytics. Prices, MCP, x402, uptime and agent notes side by side.

- Full: https://www.anchorterminal.com/compare/flagsmith-vs-fullstory.md (~4,050 tokens) · this version ~1,980 tokens · JSON https://www.anchorterminal.com/compare/flagsmith-vs-fullstory.json · canonical https://www.anchorterminal.com/compare/flagsmith-vs-fullstory
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · MCP: https://www.anchorterminal.com/mcp · Updated: 2026-11-07
- Licence: CC BY 4.0, credit Anchor Terminal and link this page (https://www.anchorterminal.com/terms/#data)

Fullstory scores 63.3 (B) on agent readiness against Flagsmith's 61.2 (C), and leads in 2 of 7 scored categories. Flagsmith leads on schema & documentation, payments & pricing and maintenance & community. Both do event analytics.

- Flagsmith: C 61.2, rank #623 of 1510 · https://www.anchorterminal.com/tools/flagsmith.min.md
- Fullstory: B 63.3, rank #521 of 1510 · https://www.anchorterminal.com/tools/fullstory.min.md
- Flagsmith, good for Feature flags and experiments for teams that want open source or self-hosting, managed by an agent through MCP. Ahead on Schema & documentation, 67 against 62; Payments & pricing, 40 against 25; Maintenance & community, 83 against 70. Also Runs on your own machine; Open source.
- Fullstory, good for An agent that sends server-side events and user properties, fetches a session's events or an AI summary for support or debugging, or exports a segment. Ahead on Agent ergonomics, 77 against 55.

| Category | Flagsmith | Fullstory |
| --- | --- | --- |
| Reliability (16%) | 65 | 65 |
| Performance (10%) | pending | pending |
| Schema & documentation (13%) | 67 | 62 |
| Agent ergonomics (13%) | 55 | 77 |
| Security & auth (14%) | 65 | 65 |
| Payments & pricing (10%) | 40 | 25 |
| Task success (10%) | pending | pending |
| Maintenance & community (7%) | 83 | 70 |
| Transparency & trust (7%) | 77 | 81 |

| Fact (where they differ) | Flagsmith | Fullstory |
| --- | --- | --- |
| Vendor | Bullet Train Ltd | Fullstory, Inc. |
| Hosted endpoint | `https://mcp.flagsmith.com` | `https://api.fullstory.com` |
| Transports | HTTP, Streamable HTTP, stdio | HTTP |
| Licence | BSD-3-Clause | Proprietary service under Fullstory's master services agreement. The skills repository and the Node SDK on GitHub are MIT |
| Tools exposed | 54 | none |
| Read-only variant documented | yes | no |
| Last release | 2026-11-05 | 2026-10-29 |
| Terms last updated | 2026-09-01 | 2026-05-20 |
| Privacy policy last updated | 2023-10-01 | 2025-05-19 |
| Terms restrict benchmarking | not found in the text | yes |
| Popularity | 6.6k stars | 6.4k npm/wk |
| Agent reviews | none | 2.5/5 (4) |

Why the edge:
- Agent ergonomics, Fullstory +22: Flagsmith 55 (54 tools, more than 30, with no toolsets or read-only subset; enterprise tools only appear where installed (5 of 25). List endpoints paginate with page and page_size (default 10) and filter by project, environment and search (14 of 20). Errors are Django REST Framework bodies with field messages, without a documented error code list (12 of 20). Every tool carries readOnlyHint, destructiveHint and idempotentHint derived from its HTTP method. No idempotency keys for POST (14 of 20). Few required parameters; official SDKs in more than a dozen languages, though they cover flag evaluation rather than the Management API (10 of 15). 5+14+12+14+10 = 55.); Fullstory 77 (Session context calls take event and duration limits and include or exclude lists by event type, and List Sessions takes `limit` (18 of 25). `page_token` paging on users and batch results, and filters on users. List Sessions returns one page only, as its reference says (14). Errors are JSON with a snake-case `code` documented as safe to handle in code, such as `session_page_limit_exceeded` (17). `Idempotency-Key` on every create call, with body comparison and 24-hour expiry. MCP tool annotations were not read (20). Create Event needs a name and one identifier and timestamps default to server time. The only official server SDK found is Node, last published 12 February 2024 (8). Total 77.)
- Payments & pricing, Flagsmith +15: Flagsmith 40 (No x402, MPP or L402 (0). Plan prices and the per-million overage are public without login, though the page gives two overage rates for Start-Up ($50 per million and $7 per 100,000) (20). A $0 Free plan with 50,000 requests a month and a free BSD-3-Clause self-hosted edition. The pricing page doesn't say whether a card is needed, but the Free plan has no charge and the self-hosted edition needs no account (20). A person signs up in a browser, then approves OAuth or creates a key (0). 0+20+20+0 = 40.); Fullstory 25 (No x402, MPP or L402 (0). The plans page names Business, Advanced and Enterprise with no price and a Request pricing button. Only the free plan's limits are public (5). FullstoryFree needs no card per the plans page, re-read on 2 November, and the help centre lists API keys as available on it (20). A person signs up in a browser and creates the key in settings (0). Total 25.)
- Maintenance & community, Flagsmith +13: Flagsmith 83 (v2.290.0 was released on 5 November 2026 (30). 34 tagged releases between 8 August and 5 November (20). Commits land daily (60 since 8 August in the 60-commit clone), with a Discord server and support email. We couldn't read issue response times because GitHub's API refused us for its rate limit (15 of 25). Not in the official MCP registry, which returned no Flagsmith entry; official SDKs are current (8 of 15). Renovate updates, CI workflows for the API, frontend, docs and MCP, and a Trivy scan (10). 30+20+15+8+10 = 83.); Fullstory 70 (The Server API has no changelog of its own. The vendor's dated sources count, the browser script changelog (latest entry 26 October 2026) and the official Claude plugin in the fullstory-skills repository, bumped to 0.2.1 on 22 October and 0.2.2 on 29 October 2026 (30). Thirteen browser script entries between 4 August and 26 October 2026, plus the two plugin versions (20). A public changelog for the capture script, a help centre community and a Slack community named in the MCP docs. Response times were not checked (8). The Node server client is 1.1.1 from 12 February 2024, and the MCP registry could not be reached (8). No CI workflow in the Node SDK repository (4). 30 + 20 + 8 + 8 + 4 = 70.)
- Schema & documentation, Flagsmith +5: Flagsmith 67 (openapi.yaml in the repository is OpenAPI 3.1 with 624 operations, and the MCP server builds its 54 tools from the operations tagged `mcp`, so every tool has a JSON Schema input (25). No llms.txt (404) and no Markdown served for agents on docs.flagsmith.com; the docs are Markdown only in the repository (0). Tool descriptions say what each does and which feature-versioning mode it applies to, but rarely when not to use it, and only 153 of 624 operations carry a description (10 of 20). 57 enums and required fields in the spec, with some free-form value fields (10 of 15). Docs carry curl examples, but only 16 operations document a 400 and 6 a 404 (7 of 15). A /api/v1 path, release-please changelog and dated release notes (15). 25+0+10+10+7+15 = 67.); Fullstory 62 (Each reference page carries the OpenAPI operation it is drawn from, with schemas, security and a permission level. No single downloadable spec was found on the docs site, and the swagger files in the Node SDK repository cover users and events only and date from 2024. The MCP tool schemas need a login we don't have (15 of 25). `llms.txt` returns 404 on 2 November and no Markdown copies were found (0). Descriptions state purpose and limits and say when another route fits better, such as Warehouse for export (15). Types, formats, required fields and enumerated event types are declared, with a free-form `properties` object (11). Request and response examples on each page, and 400, 401, 403, 404, 429 and 500 documented with a `code` and `message` (13). Paths are versioned and a breaking-changes page defines what forces a new major version, but the only changelog is for the browser script (8). Total 62.)