# Flagsmith vs LaunchDarkly (slim)

> LaunchDarkly scores 71.3 (BB) to Flagsmith's 61.2 (C) for feature flags. Prices, MCP, x402, uptime and agent notes side by side.

- Full: https://www.anchorterminal.com/compare/flagsmith-vs-launchdarkly.md (~4,050 tokens) · this version ~2,080 tokens · JSON https://www.anchorterminal.com/compare/flagsmith-vs-launchdarkly.json · canonical https://www.anchorterminal.com/compare/flagsmith-vs-launchdarkly
- 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)

LaunchDarkly scores 71.3 (BB) on agent readiness against Flagsmith's 61.2 (C), and leads in 5 of 7 scored categories. Both do feature flags.

- Flagsmith: C 61.2, rank #620 of 1486 · https://www.anchorterminal.com/tools/flagsmith.min.md
- LaunchDarkly: BB 71.3, rank #162 of 1486 · https://www.anchorterminal.com/tools/launchdarkly.min.md
- Flagsmith, good for Feature flags and experiments for teams that want open source or self-hosting, managed by an agent through MCP. Also Open source.
- LaunchDarkly, good for An agent that creates and targets feature flags, runs rollouts and experiments, reads experiment results and cleans up stale flags. Ahead on Reliability, 74 against 65; Schema & documentation, 89 against 67; Agent ergonomics, 69 against 55. Also Agent-ready, a grade of BB or better; Free to start without a card.

| Category | Flagsmith | LaunchDarkly |
| --- | --- | --- |
| Reliability (16%) | 65 | 74 |
| Performance (10%) | pending | pending |
| Schema & documentation (13%) | 67 | 89 |
| Agent ergonomics (13%) | 55 | 69 |
| Security & auth (14%) | 65 | 66 |
| Payments & pricing (10%) | 40 | 40 |
| Task success (10%) | pending | pending |
| Maintenance & community (7%) | 83 | 82 |
| Transparency & trust (7%) | 77 | 81 |

| Fact (where they differ) | Flagsmith | LaunchDarkly |
| --- | --- | --- |
| Vendor | Bullet Train Ltd | Catamorphic, Co. (dba LaunchDarkly) |
| Hosted endpoint | `https://mcp.flagsmith.com` | `https://mcp.launchdarkly.com/mcp/launchdarkly` |
| Licence | BSD-3-Clause | Proprietary service under LaunchDarkly's terms. The local MCP server is MIT and the ldcli CLI is Apache-2.0 |
| Tools exposed | 54 | 141 |
| Read-only variant documented | yes | no |
| llms.txt | no | yes |
| Last release | 2026-11-05 | 2026-10-27 |
| Terms last updated | 2026-09-01 | 2025-09-08 |
| Privacy policy last updated | 2023-10-01 | 2025-04-08 |
| Terms restrict benchmarking | not found in the text | yes |
| Popularity | 6.6k stars | 3.3M npm/wk, 2.2M PyPI/wk |
| Agent reviews | none | 3.5/5 (4) |

Why the edge:
- Schema & documentation, LaunchDarkly +22: 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.); LaunchDarkly 89 (OpenAPI 3.0.3 served without a login at app.launchdarkly.com/api/v2/openapi.json, with 253 paths and 401 operations (25). The hosted MCP input schemas need a sign-in and were not read. A docs index for agents at launchdarkly.com/docs/llms.txt, and docs pages answer as Markdown with .md (10). 399 of 401 operations have a description. The MCP tool descriptions on the server page average about 740 characters and state pagination, sorting, plan limits and which tool to call next (17). 169 enums across 746 schemas. JSON patch bodies and semantic patch instructions are loosely typed objects (9). 1,853 examples in the spec, 429 documented on 287 operations and 403 on 355, and an error table with a suggested fix for each status (13). Dated API versions chosen by header or per token, a version changelog with end-of-life dates and a dated docs changelog (15).)
- Agent ergonomics, LaunchDarkly +14: 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.); LaunchDarkly 69 (The hosted MCP server lists 141 tools, far past 30 (5). The OAuth metadata names reader, writer and observability scopes, but no tool filter for the hosted server was found. The `--tool` and `--scope read` options belong to the local server, which has 30 tools since v0.7.2 (27 October 2026), so 3 of 10 added back (8). The API has `limit` and `offset` on 61 operations, filters and sorting, summary and detailed representations and an `expand` parameter on 40 (18). Errors carry `code`, `message` and `id`, with a table of statuses and fixes (15). The server page marks 73 tools read-only, 35 destructive and 89 idempotent. There are no idempotency keys on REST writes, and JSON patch can test a version before applying (15). Generated API clients for TypeScript and Python (`launchdarkly-api`, tagged 25.1.1 on 23 October 2026) and the `ldcli` CLI, with semantic patch needing a special content type (13).)
- Reliability, LaunchDarkly +9: Flagsmith 65 (Graded on Flagsmith Cloud with the hosted lines. Statuspage at status.flagsmith.com with components for the Edge API, Admin API, dashboard and website (20). In the 90 days from 8 August, an Admin and SDK API outage on 28 October marked critical, posted at 21:56 UTC and resolved at 22:12 with no cause given, and a minor delay in processing flag changes on 10 September. The posted span of the outage is 16 minutes and its start isn't stated, so we read it as one serious incident under an hour (15 of 30). The Management API limit of 500 requests a minute is documented (15). No 429 handling, Retry-After or idempotency guidance was found in the docs (0). A public SLA commits to 99.95 per cent monthly uptime with service credits (10). The Management API is generally available, but the MCP docs call the server an early release, so half (5 of 10). 20+15+15+0+10+5 = 65.); LaunchDarkly 74 (Graded on the hosted service with the hosted lines. Statuspage at status.launchdarkly.com with 51 components and incident history (20). Read from the history feed (the host's robots.txt disallows /api/), nine incidents between 3 August and 1 November 2026, each hitting one product, one region or a share of requests, so all read as minor. They were server-side streaming errors on 7 August, delayed flag updates in us-east-1 on 14 August, delayed polling updates on 17 August (a CDN provider), sign-up and notification emails failing from 22 to 24 August, 12 minutes of streaming errors for new connections on 26 August, elevated application and API errors with custom role management failing from 2 to 3 October (about 19 hours, with most other functions working), delayed guarded rollouts the same night, 0.7 per cent of requests failing for 21 minutes on 15 October and delayed event processing on 26 October. The 10 July outage, marked critical, has left the window (20). The API docs describe global, route, token and IP limits and say the numbers are not published. Limit and remaining headers report them at run time (5 of 15). 429s carry reset headers, IP limits carry `Retry-After`, and the docs ask for jitter and backoff. No idempotency keys were found, though JSON patch can test a resource version and 409 is documented as retryable (11 of 15). The SLA commits to 99.9 per cent for Enterprise support and 99.99 per cent for Premium support (10). The REST API and hosted MCP server carry no beta label, but 132 of 401 API operations are beta (8 of 10).)