Gauge CLI vs Langfuse API + MCP

Gauge CLI 60

CLI reading. No machine-readable contract, -o json on read commands (10 of 25). No llms.txt; instructions bundled in the CLI for agents (5). The README says what it finds and when local or hosted fits (16 of 20). Commands with help text; typed flags (9 of 15). Worked examples, no error reference (8 of 15). Dated changelog and semver tags (12 of 15). 10 + 5 + 16 + 9 + 8 + 12 = 60.

Langfuse API + MCP 93

Public OpenAPI at cloud.langfuse.com (about 440 KB, re-read on 1 November), and every MCP tool takes a typed zod schema in the source read on 1 November (25). llms.txt and Markdown docs, with every page available as Markdown at .md (10). Tool descriptions say what to use each one for and how to size the result. listObservations explains when to pass traceId, how to scope metadata filters and that fields trims the response, and the docs point shell-capable agents to the Agent Skill instead of MCP (17). Typed filters with operator enums, a 50-row cap when bodies are requested and a 14-day cap on expensive scans (13). Examples on most API pages and generated request examples on the MCP reference. Error bodies are less fully documented (13). Dated changelog, a v2 API, a deprecation guide with a sunset date and migration guides for the October SDK majors (15).

Gauge CLI 53

MIT (30). Local data stays in .gauge/ and telemetry fields are listed; hosted data handling wasn't read (18 of 30). Dated changelog, no deprecation policy (10 of 20). Telemetry on by default, disclosed with an opt-out (20). 30 + 18 + 10 + 20 = 78.

Langfuse API + MCP 86

MIT core with the ee directories under a commercial licence (27). Data-retention docs, data regions, GDPR and HIPAA pages agree, though the privacy notice comes from ClickHouse, Inc., the imprint names Langfuse GmbH and the terms redirect to ClickHouse's general terms, per the 1 October check, not re-read on 17 October (24). Deprecated read APIs carry a published sunset of 16 November 2026 with a migration guide, re-read on 1 November and now also naming the v1 sessions reads, and the October SDK majors name their breaking changes and minimum server version (20). Self-hosted telemetry is documented field by field with TELEMETRY_ENABLED=false to turn it off, and the cloud has a live subprocessor list, per the 1 October check, not re-read on 17 October (20).

Gauge CLI 55

Local tool. Agent credentials stay on your machine in local mode; hosted login with a device flow (20 of 30). Test agents run in fresh Docker sessions with injected inputs, and the gateway brokers credentials in hosted mode (12 of 20). Agents under test read your product's docs and outputs, with no prompt-injection guidance (5 of 15). Local transcripts and SQLite evidence per run (10 of 15). No security policy found (8 of 20). 20 + 12 + 5 + 10 + 8 = 55.

Langfuse API + MCP 77

Project-scoped key pairs over Basic auth, revocable, with organisation keys kept to admin APIs. Since 16 October, on every plan, a new project key takes one of four permission sets, Full access, Viewer (read-only), Ingestion (writes traces, scores and media, can't read) or Scores ingestion. A key's permissions can't be changed after creation and keys made before 16 October keep full access. Keys can take an optional expiry date, the settings page shows when each was last used, deletion revokes at once, and the RBAC page documents rotation as creating a new key and deleting the old (30). A Viewer key is read-only on the public API. The MCP server's source, re-read at v4.72.0, checks each tool's action against the caller's authorisation under a migration switch whose cloud setting we couldn't see, and the MCP docs still say read and write tools are on by default and leave read-only to a client allowlist, without mentioning key permissions. Annotations mark reads and destructive tools (14). Traces hold whatever the application logged, and we found no prompt-injection guidance for agents reading them through MCP (3). Audit logs on Enterprise only (10). Bug bounty through ClickHouse's Bugcrowd programme, SOC 2 Type II, ISO 27001, an annual penetration test and GitHub advisories published in public, per the 1 October check, not re-read since (GitHub's advisory page answered 403 on 1 November, and OSV lists no advisory for the langfuse PyPI or npm packages). langfuse.com/.well-known/security.txt returned 404 on 1 November (20).

Gauge CLI 60

Local package. Installs from npm as @withgauge/cli with Node 22.13 or later and Docker stated (20). checks.yml runs npm run check on push and pull request across a matrix, and the repository has 76 test files; whether main passes wasn't read (20 of 25). Issues weren't read (5, unchecked). A dated changelog with Added sections per release (15). Version 0.28.0 (0). 20 + 20 + 5 + 15 + 0 = 60.

Langfuse API + MCP 80

incident.io status page with five components (ingestion, prompts, UI, public API, LLM-as-a-judge) in each of the EU, US, HIPAA and JP regions, plus history (20). The history page, re-read on 1 November, dates each component's impact. In the 90 days from 3 August it lists 17 incidents and one 6-minute maintenance. 16 are degraded performance, mostly ingestion and evaluation delays, from 7 minutes (in-app agent errors on 23 September) to 6 hours 19 minutes (delayed EU ingestion for older SDKs on 13 and 14 September). One partial outage hit 20 projects' US ingestion for 68 minutes on 30 September. Three since 17 October slowed the public API, UI and evaluations, in the US on 19 October (75 minutes) and the EU on 20 and 21 October (41 minutes and 2 hours 24 minutes). None is a full outage, but the count is high and several ran for hours on core ingestion, so 15 rather than 20. Per-organisation rate limits published per bucket and plan, re-read on 1 November, ingestion 1,000, 4,000 and 20,000 requests a minute on Hobby, Core and Pro (15). 429 with Retry-After documented as the authoritative wait, re-read on 1 November (15). Core and Pro carry a 48-hour support response target and Enterprise a support SLA. We found no uptime SLA (5). API and MCP are GA (10).

Gauge CLI 82

CLI 0.28.0 on 4 November 2026 (30). Six releases in 90 days (20). Issues and pull requests weren't read; a support address and issue tracker are published (12 of 25). Current official package (15). CI on push and pull request (5 of 10, results not read). 30 + 20 + 12 + 15 + 5 = 82.

Langfuse API + MCP 88

Server v4.72.0 tagged on 2026-10-29 (30). Nine v4 server tags from v4.64.0 on 19 October to v4.72.0 on 29 October, after 14 from 2 to 16 October, and v3.225.13 to v3.225.15 for the older line (20). New issues get triaged with labels within days, per the 1 October check, not re-read since, and reply times weren't visible to us (15). Python SDK v5.1.0 tagged on 2026-10-30 and JS SDK v6.1.0, current majors built for Langfuse v4 (15). CodeQL, Semgrep, Snyk and zizmor run in CI alongside the build pipeline. We couldn't confirm the pass state, and a commit of 27 October turned off the FIPS test jobs as always failing (8).