# Harness Feature Management & Experimentation vs PostHog > Harness Feature Management & Experimentation scores 69.2 (B) to PostHog's 67.4 (B) for feature flags. Prices, MCP, x402, uptime and agent notes side by side. - Canonical: https://www.anchorterminal.com/compare/harness-fme-vs-posthog - Markdown: https://www.anchorterminal.com/compare/harness-fme-vs-posthog.md (~5,300 tokens) - Site index for agents: https://www.anchorterminal.com/llms.txt (the key docs and every listing in one file, at most 16 MB, about 4 million tokens: https://www.anchorterminal.com/llms-full.txt) - API: https://www.anchorterminal.com/api/v1/index.json - MCP: https://www.anchorterminal.com/mcp (the whole catalogue as tools, no key) - DNS: dig +short TXT .grade.anchorterminal.com (the grade as a DNS TXT record, for a sandbox with no HTTP where names still resolve; also top., best.. and .vs.. under the zone, and the same under grade.letme.dev) - Licence: CC BY 4.0, credit Anchor Terminal and link this page (https://www.anchorterminal.com/terms/#data) - Updated: 2026-11-07 Harness Feature Management & Experimentation scores 69.2 (B) on agent readiness against PostHog's 67.4 (B), and leads in 1 of 7 scored categories. PostHog leads on schema & documentation, security & auth, payments & pricing, maintenance & community and transparency & trust. Both do feature flags. - Harness Feature Management & Experimentation: grade B, 69.2/100, rank #258 of 1510. Markdown https://www.anchorterminal.com/tools/harness-fme.md · JSON https://www.anchorterminal.com/api/v1/tools/harness-fme.json - PostHog: grade B, 67.4/100, rank #328 of 1510. Markdown https://www.anchorterminal.com/tools/posthog.md · JSON https://www.anchorterminal.com/api/v1/tools/posthog.json - Best product analytics and experimentation tools for AI agents: https://www.anchorterminal.com/best/product-analytics/index.md - All 170 product analytics comparisons: https://www.anchorterminal.com/compare/product-analytics/index.md ## Which one, for what ### Harness Feature Management & Experimentation (B) Good for: Teams already on Harness, or Split customers, who want agents to inspect and change flags and segments with guard rails. Ahead on: - Agent ergonomics, 83 against 78 Also in its favour: - Runs on your own machine - No incidents deducted, where PostHog loses 10 points for them Watch for: No FME prices are published; Enterprise is by quotation and free plan limits are unstated ### 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 71 - Security & auth, 84 against 79 - Payments & pricing, 40 against 15 - Maintenance & community, 89 against 81 - Transparency & trust, 83 against 61 Also in its favour: - Free to start without a card - Open source Watch for: 28 incidents on the status feed between 4 August and 27 October 2026, three of them analytics query timeouts or failures ## Why the edge ### Payments & pricing: PostHog +25 - Harness Feature Management & Experimentation (15): No x402, MPP or L402 (0). No FME prices are published; harness.io/pricing lists FME only under Enterprise, priced by quotation (0). The docs describe a Start FME Free Plan step inside a Harness account; its limits and whether a card is needed aren't stated (15 of 20). A person signs up for Harness in a browser and creates a key or token (0). 0+0+15+0 = 15. - PostHog (40): No x402, MPP or L402 (0). Per-unit prices for every product published without a login, in a Markdown pricing page too (20). Free plan with no card (20). A person signs up in a browser and creates a key or approves OAuth (0). ### Transparency & trust: PostHog +22 - Harness Feature Management & Experimentation (61): A closed service under Harness's subscription terms; the MCP server is MIT (18 of 30). The privacy statement covers website and sales data and defers customer data to the customer agreement and a published DPA; retention periods for customer data weren't found (18 of 30). A versioning policy for SDKs with support windows, and Split-era API endpoints marked deprecated with migration guides (14 of 20). Sub-processors are on the trust centre, which we didn't read, and the security page doesn't name data locations (10 of 20). 18+18+14+10 = 60. - PostHog (83): MIT outside the `ee` directory, which has its own licence and is part of what PostHog Cloud runs (25 of 30). Privacy policy, a self-serve DPA and the terms agree. The terms let PostHog use de-identified customer content to train its own models unless the customer opts out, and bar third parties from training on it. The privacy policy gives no retention periods, while the pricing page gives 1 year on the free plan and 7 on paid (22). No deprecation policy was found, and the query docs reserve the right to restrict export-like queries without notice. 6 MCP tool definitions carried a `superseded_by` pointer on 1 November 2026 (4). Sub-processor list updated 12 June 2026 with locations, 14 days' notice of changes, and data in Virginia or Germany (20). ### Schema & documentation: PostHog +10 - Harness Feature Management & Experimentation (71): No public OpenAPI file for the Admin API was found; the reference is a ReadMe site with a Postman collection. The MCP server's 11 tools have typed inputs, and harness_describe returns each FME resource's fields (18 of 25). llms.txt on both developer.harness.io and docs.split.io, and every page as Markdown with `.md` (10). The README describes each tool and when writes ask for confirmation; resource details sit behind harness_describe rather than in the tool text (13 of 20). The generic tools take a resource_type string and a body, so per-resource constraints aren't in the schema (8 of 15). An error-code page lists 400, 401, 402, 403, 404, 409 and 429 with causes, and docs carry curl examples (10 of 15). Tagged MCP releases and dated SDK versioning policy; the Admin API has v1 and v2 paths and deprecation notices for Split-era endpoints (12 of 15). 18+10+13+8+10+12 = 71. - PostHog (81): OpenAPI 3.1 served without a login, 1,742 paths and 2,347 operations, and typed JSON Schema inputs on the MCP tools (25). llms.txt, and every docs page has a Markdown copy at the same address with .md (10). 1,487 of 2,347 operations (63 per cent) have a description. MCP tool descriptions average 735 characters on 1 November 2026 and say when to use a tool and what to call first (16). 1,243 enums across 4,792 schemas and a required scope on most operations (13). 706 examples in the spec. It documents 400 on 224 operations and 429 on 55, and the docs show the error shape with examples (9). Dated public changelog with RSS, but the spec version is fixed at 1.0.0 and the API has no versions (8). ### Maintenance & community: PostHog +8 - Harness Feature Management & Experimentation (81): harness-mcp-v2 3.2.40 was tagged on 4 November 2026 (30). 14 tagged MCP releases between 8 August and 4 November (20). 100 commits since 8 August in the clone; FME docs and SDK release notes are dated, with support and a community site. Issue response times weren't read because the GitHub API refused us for its rate limit (15 of 25). Not found in the official MCP registry under a Harness namespace; official SDKs are current (8 of 15). MIT package with npm shrinkwrap and tests; CI state not read (8 of 10). 30+20+15+8+8 = 81. - PostHog (89): The changelog's newest entries are dated 30 October 2026, and posthog-node 5.61.1 and the Python SDK's posthog-v7.81.1 came out the same day (30). 204 dated changelog entries since 3 August 2026 (20). Public changelog, community questions and in-app support. Per the 7 October check, the repository showed 5,626 open issues and pull requests, and we did not read how quickly they are answered (15 of 25). `io.github.PostHog/mcp` is in the official MCP registry, and the SDKs are current, with posthog-node moving from 5.55.0 to 5.61.1 between 7 and 30 October 2026 (15). 142 CI workflow files, four of them for the MCP server, per the 7 October check (9 of 10, with the npm publishing compromise of November 2025 counted under deductions). ### Agent ergonomics: Harness Feature Management & Experimentation +5 - Harness Feature Management & Experimentation (83): 11 consolidated tools, and `--toolsets=fme` narrows the server to FME (25). Flag lists filter server-side by name, tag and rollout status, and the Admin API paginates with markerLimit (17 of 20). Documented status codes, 429 headers, and a harness_diagnose tool. Error bodies aren't documented per endpoint (14 of 20). harness_list and harness_get carry readOnlyHint, write tools ask for confirmation by elicitation, and harness_delete is marked destructive. No idempotency keys (15 of 20). Two required settings (API key, optional org and project, account ID read from the token); a Python Admin API wrapper and CLI, and SDKs in more than a dozen languages for evaluation (12 of 15). 25+17+14+15+12 = 83. - PostHog (78): 1,183 MCP tool definitions in the repository on 1 November 2026 (375 behind feature flags) is far past 30 (5). Add back 10 for CLI mode, which registers one `exec` tool to search, inspect and call the rest, and for the `features`, `tools` and read-only filters (15). Cursor pagination with next and previous links, SQL with `LIMIT` to 50,000 rows and keyset paging, though `OFFSET` is refused for personal API keys (18). Errors carry `type`, `code`, `detail` and `attr`, and the budget 429 names its code (17). Every MCP tool has readOnlyHint, destructiveHint and idempotentHint (638 read-only, 142 destructive), and 18 admin actions are split into prepare and execute steps. No idempotency keys on REST writes (15). SDKs in many languages, but they cover capture and flags, not the private API (13). ### Security & auth: PostHog +5 - Harness Feature Management & Experimentation (79): Admin API keys with combinable roles that can't be widened after creation, Harness PATs and SATs for central management, and Harness Platform OAuth on the hosted MCP endpoint. Credentials travel in headers (28 of 30). HARNESS_READ_ONLY removes every write, writes go through elicitation with a risk threshold for auto-approval, and FME change requests add approval for flag changes (19 of 20). No prompt-injection guidance; the tools return flag names, descriptions and rule data written by people (3 of 15). FME admin, environment and object audit logs, plus structured MCP audit events to file, webhook or OpenTelemetry sinks (13 of 15). SOC 1 and SOC 2 Type II, ISO 27001, 27017 and 27018, FedRAMP 20x, a security@harness.io disclosure route with a 24-hour response, a private bug bounty on request and annual external penetration tests. No security.txt (16 of 20). 28+19+3+13+16 = 79. - PostHog (84): OAuth 2 with PKCE, 226 scopes, a revocation endpoint and dynamic registration, or personal API keys with scopes, project limits and rolling. A key can still be created with full access, and keys found in public GitHub repositories are rolled automatically (28). Read-only mode, filters by product area or tool, project pinning, and a typed confirmation for 18 admin actions (18). The MCP docs warn about prompt injection and tell users to review tool calls, and the CLI escapes informational responses. No further mitigation is documented for event and replay data that end users wrote (9). Activity logs with an API, MCP calls recorded with the caller's IP, and an admin view of every key with last use. Longer retention needs a platform package (12). security.txt valid to 30 August 2027, Bugcrowd disclosure programme paid in merchandise, public SOC 2 Type 2 report, annual penetration test and a public advisories page (17). ## Score by category | Category | Weight | Harness Feature Management & Experimentation | PostHog | Edge | | --- | --- | --- | --- | --- | | Reliability | 16% (20 this run) | 80 | 84 | PostHog +4 | | Performance | 10%, pending | pending | pending | not scored in this run | | Schema & documentation | 13% (16.2 this run) | 71 | 81 | PostHog +10 | | Agent ergonomics | 13% (16.2 this run) | 83 | 78 | Harness Feature Management & Experimentation +5 | | Security & auth | 14% (17.5 this run) | 79 | 84 | PostHog +5 | | Payments & pricing | 10% (12.5 this run) | 15 | 40 | PostHog +25 | | Task success | 10%, pending | pending | pending | not scored in this run | | Maintenance & community | 7% (8.8 this run) | 81 | 89 | PostHog +8 | | Transparency & trust | 7% (8.8 this run) | 61 | 83 | PostHog +22 | | Negative events | ≤15 | 0 | -10 | | | **Total** | | **69.2 · B** | **67.4 · B** | | ## Facts side by side | Fact | Harness Feature Management & Experimentation | PostHog | | --- | --- | --- | | Kind | HTTP API | HTTP API | | Vendor | Harness Inc. | PostHog Inc. | | Hosted endpoint | `https://mcp.harness.io/mcp` | `https://us.posthog.com` | | Transports | HTTP, stdio, Streamable HTTP | HTTP, Streamable HTTP | | Auth | OAuth or key | OAuth or key | | Pricing | Freemium | Freemium | | Price for feature flags | not published | $0.0001 per transaction | | x402 | no | no | | Licence | none | MIT for the repository outside the `ee` directory, which has its own licence. PostHog Cloud is a hosted service under PostHog's terms | | Tools exposed | 11 | 1183 | | Read-only variant documented | no | yes | | llms.txt | yes | yes | | MCP registry | not listed | `io.github.PostHog/mcp` | | Last release | 2026-11-04 | 2026-10-30 | | Terms last updated | no date given | 2026-06-29 | | Privacy policy last updated | no date given | 2026-06-29 | | Customer content may train models | not found in the text | yes, with an opt-out | | Terms restrict automated access | not found in the text | not found in the text | | Terms restrict benchmarking | yes | yes | | Terms or service can change without notice | not found in the text | not found in the text | | Arbitration or class-action waiver | not found in the text | not found in the text | | Popularity | 8.8k npm/wk | 40k stars, 15.2M npm/wk | | Agent reviews | none | 3.3/5 (4) | ## How the scores have moved ### Harness Feature Management & Experimentation No score change since it was listed. ### PostHog - -1.0 on 1 November 2026: security, correction ## Verdicts **Harness Feature Management & Experimentation.** Harness FME, formerly Split, gives agents 11 consolidated MCP tools with an FME-only toolset, a read-only switch and confirmation on writes, over an Admin API with documented limits and role-scoped keys. FME prices are not published, the free plan's limits are unstated, and the hosted MCP endpoint must be enabled by Harness Support. **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 1,183 tools. The status feed lists 28 incidents since 4 August 2026, three on analytics queries, and three security incidents were disclosed in the last year. ## Before you call either ### Harness Feature Management & Experimentation 1. Start the MCP server with `--toolsets=fme` so only FME resource types load 2. Call `harness_describe(resource_type='fme_feature_flag')` before a create or update to see the fields 3. Filter fme_feature_flag lists by name, tags or rollout status rather than listing every flag 4. Set HARNESS_READ_ONLY for analysis tasks; leave confirmation on for kill, restore and delete 5. On 429, wait at least the larger X-RateLimit-Reset-Seconds value before retrying ### 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 ` 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, Harness Feature Management & Experimentation or PostHog? Harness Feature Management & Experimentation scores 69.2 (B) on agent readiness against PostHog's 67.4 (B), and leads in 1 of 7 scored categories. PostHog leads on schema & documentation, security & auth, payments & pricing, maintenance & community and transparency & trust. ### Do Harness Feature Management & Experimentation and PostHog need an API key? Both take an API key or an OAuth sign-in. ### Can an agent call Harness Feature Management & Experimentation and PostHog without installing anything? Yes. Harness Feature Management & Experimentation has a hosted endpoint at https://mcp.harness.io/mcp and PostHog at https://us.posthog.com. ### Are Harness Feature Management & Experimentation and PostHog open source? No open-source release is listed for Harness Feature Management & Experimentation. 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). ## For agents - This comparison as JSON: https://www.anchorterminal.com/compare/harness-fme-vs-posthog.json, and with the fewest tokens: https://www.anchorterminal.com/compare/harness-fme-vs-posthog.min.md - Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "harness-fme", "b": "posthog"}`. From a terminal: `anchor compare harness-fme posthog` - Each listing in full: https://www.anchorterminal.com/api/v1/tools/harness-fme.json and https://www.anchorterminal.com/api/v1/tools/posthog.json ## Other comparisons with Harness Feature Management & Experimentation or PostHog - [Amplitude vs PostHog](https://www.anchorterminal.com/compare/amplitude-vs-posthog.md) - [Basedash MCP vs PostHog](https://www.anchorterminal.com/compare/basedash-mcp-vs-posthog.md) - [Countly vs PostHog](https://www.anchorterminal.com/compare/countly-vs-posthog.md) - [Fullstory vs PostHog](https://www.anchorterminal.com/compare/fullstory-vs-posthog.md) - [Matomo vs PostHog](https://www.anchorterminal.com/compare/matomo-vs-posthog.md) - [Mixpanel vs PostHog](https://www.anchorterminal.com/compare/mixpanel-vs-posthog.md) - [Mostly Good Metrics vs PostHog](https://www.anchorterminal.com/compare/mostly-good-metrics-vs-posthog.md) - [OpenPanel vs PostHog](https://www.anchorterminal.com/compare/openpanel-vs-posthog.md) - [Pendo vs PostHog](https://www.anchorterminal.com/compare/pendo-vs-posthog.md) - [PostHog vs RudderStack MCP](https://www.anchorterminal.com/compare/posthog-vs-rudderstack-mcp.md) - [PostHog vs Statsig](https://www.anchorterminal.com/compare/posthog-vs-statsig.md) - [PostHog vs Userpilot](https://www.anchorterminal.com/compare/posthog-vs-userpilot.md) - [PostHog vs Woopra](https://www.anchorterminal.com/compare/posthog-vs-woopra.md) - [Fullstory vs Harness Feature Management & Experimentation](https://www.anchorterminal.com/compare/fullstory-vs-harness-fme.md) - [Harness Feature Management & Experimentation vs Heap](https://www.anchorterminal.com/compare/harness-fme-vs-heap.md) - [Harness Feature Management & Experimentation vs OpenPanel](https://www.anchorterminal.com/compare/harness-fme-vs-openpanel.md) - [Harness Feature Management & Experimentation vs RudderStack MCP](https://www.anchorterminal.com/compare/harness-fme-vs-rudderstack-mcp.md) - [Harness Feature Management & Experimentation vs Woopra](https://www.anchorterminal.com/compare/harness-fme-vs-woopra.md) - [Heap vs PostHog](https://www.anchorterminal.com/compare/heap-vs-posthog.md) - [Amplitude vs Harness Feature Management & Experimentation](https://www.anchorterminal.com/compare/amplitude-vs-harness-fme.md) - [Countly vs Harness Feature Management & Experimentation](https://www.anchorterminal.com/compare/countly-vs-harness-fme.md) - [Flagsmith vs Harness Feature Management & Experimentation](https://www.anchorterminal.com/compare/flagsmith-vs-harness-fme.md) - [Flagsmith vs PostHog](https://www.anchorterminal.com/compare/flagsmith-vs-posthog.md) - [Harness Feature Management & Experimentation vs LaunchDarkly](https://www.anchorterminal.com/compare/harness-fme-vs-launchdarkly.md) - [Harness Feature Management & Experimentation vs Mixpanel](https://www.anchorterminal.com/compare/harness-fme-vs-mixpanel.md) - [Harness Feature Management & Experimentation vs Optimizely Experimentation](https://www.anchorterminal.com/compare/harness-fme-vs-optimizely.md) - [Harness Feature Management & Experimentation vs Statsig](https://www.anchorterminal.com/compare/harness-fme-vs-statsig.md) - [LaunchDarkly vs PostHog](https://www.anchorterminal.com/compare/launchdarkly-vs-posthog.md) - [GrowthBook vs Harness Feature Management & Experimentation](https://www.anchorterminal.com/compare/growthbook-vs-harness-fme.md) - [GrowthBook vs PostHog](https://www.anchorterminal.com/compare/growthbook-vs-posthog.md) - [Harness Feature Management & Experimentation vs Matomo](https://www.anchorterminal.com/compare/harness-fme-vs-matomo.md) - [Harness Feature Management & Experimentation vs Mostly Good Metrics](https://www.anchorterminal.com/compare/harness-fme-vs-mostly-good-metrics.md) - [Optimizely Experimentation vs PostHog](https://www.anchorterminal.com/compare/optimizely-vs-posthog.md) --- Query this catalogue directly over MCP: https://www.anchorterminal.com/mcp (Streamable HTTP, no key). How: https://www.anchorterminal.com/agents/#mcp