# Gauge CLI vs Prefactor

> Prefactor scores 61.5 (C) to Gauge CLI's 60.4 (C) for evaluations. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/gauge-cli-vs-prefactor
- Markdown: https://www.anchorterminal.com/compare/gauge-cli-vs-prefactor.md (~3,750 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 <slug>.grade.anchorterminal.com (the grade as a DNS TXT record, for a sandbox with no HTTP where names still resolve; also top., best.<category>. and <a>.vs.<b>. 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: 2026-11-06

Prefactor scores 61.5 (C) on agent readiness against Gauge CLI's 60.4 (C), and leads in 3 of 7 scored categories. Gauge CLI leads on reliability. Both do evaluations.

- Gauge CLI: grade C, 60.4/100, rank #590 of 1354. Markdown https://www.anchorterminal.com/tools/gauge-cli.md · JSON https://www.anchorterminal.com/api/v1/tools/gauge-cli.json
- Prefactor: grade C, 61.5/100, rank #546 of 1354. Markdown https://www.anchorterminal.com/tools/prefactor.md · JSON https://www.anchorterminal.com/api/v1/tools/prefactor.json
- Best agent tracing, monitoring and evaluation tools: https://www.anchorterminal.com/best/agent-observability/index.md
- All 250 evals comparisons: https://www.anchorterminal.com/compare/agent-observability/index.md

## Which one, for what

### Gauge CLI (C)

Good for: Teams that build skills, CLIs, SDKs or MCP servers and want to see where coding agents get stuck with them, and to test fixes before release.

Ahead on:
- Reliability, 60 against 53

Also in its favour:
- No key needed to call it
- Open source
- No incidents deducted, where Prefactor loses 3 points for them

Watch for: Collects anonymous command usage by default, with an opt-out

### Prefactor (C)

Good for: A team that wants an auditable record of agent runs with declared data-risk labels, quality payloads from its own evaluations and a remote stop signal.

Ahead on:
- Schema & documentation, 82 against 60
- Agent ergonomics, 88 against 75

Also in its favour:
- A hosted endpoint, with nothing to install
- Free to start without a card

Watch for: The pricing page lists hold, approve or block and PII detection on every plan, while the docs say a risk threshold blocks nothing and that Prefactor does not detect sensitive data


## Why the edge

### Schema & documentation: Prefactor +22

- 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.
- Prefactor (82): A public OpenAPI 3.0.0 document with 163 operations and an OpenRPC document with 165 WebSocket methods (157 and 159 on 8 October). Body parameters are declared `in: body`, which OpenAPI 3 does not define, so some generators will need adjusting (23 of 25). llms.txt with abridged and full versions of the docs (10). Operations carry one-line summaries and only 6 of 163 have a description. The concept pages are clearer and say what the product does not do (10 of 20). Named ID schemas, enums and bounds such as `page_size` 1 to 100, but span payloads are free-form by design and `start_time` and `end_time` have no schema (11 of 15). A table of 12 error codes, an error union in the spec, curl examples and a runnable WebSocket script (13 of 15). The path is versioned `/api/v1`, the SDKs keep semver changelogs, and the site changelog now has 56 dated entries, the latest on 21 October 2026 (15).

### Agent ergonomics: Prefactor +13

- Gauge CLI (75): CLI reading for an agent driving it. Bundled instructions match the installed version, and output is filterable with -o json (20 of 25). Run summaries and Findings with queryable fields (15 of 20). Errors not documented as a reference (10 of 20). Reruns from checkpoints and a recheck command with a confirm step (15 of 20). Four commands to start, Node only (15 of 15). 20 + 15 + 10 + 15 + 15 = 75.
- Prefactor (88): List calls take `pagination[page_size]` up to 100, summaries and counts are opt-in flags, and one endpoint exports a whole run's context (16 of 25). Offset pagination, sorting and filters by agent, instance, environment, time, purpose and status, with no cursor (18 of 20). Errors carry a stable `code`, a message naming the exceeded scope on 429 and a per-field map on validation failures (20). Every operation accepts `idempotency_key`, and a retried bulk request fails only the reused items. There is no MCP server to annotate (20). Official TypeScript and Python SDKs and a CLI. The Python SDK does not yet support sensitive encoding (14 of 15).

### Reliability: Gauge CLI +7

- 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.
- Prefactor (53): Graded as a hosted service. A public status page at status.prefactor.ai (UptimeRobot), though we found no link to it from the site or docs. Its monitors and history load by script from `/api/` paths that the status host's robots.txt disallows, so on 1 November we couldn't re-read which parts of the service it covers (20, as awarded on 8 October). The incident record is unread. The 8 October reading of three monitors at 100 per cent came from the same disallowed path and no longer counts, so the line takes the no-readable-history score, a limit of our reading and not a finding against Prefactor (5). Rate limits are described by scope and one-minute window with no numbers (3 of 15). 429 carries `Retry-After` and `retry_after_ms`, both SDKs retry with backoff and jitter, and every operation takes an idempotency key (15). The pricing page lists an SLA on Enterprise with no text published (0). The API is version 1.0 and `@prefactor/core` is 1.2.0, with no beta label (10).

## Score by category

| Category | Weight | Gauge CLI | Prefactor | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 60 | 53 | Gauge CLI +7 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 60 | 82 | Prefactor +22 |
| Agent ergonomics | 13% (16.2 this run) | 75 | 88 | Prefactor +13 |
| Security & auth | 14% (17.5 this run) | 55 | 56 | Prefactor +1 |
| Payments & pricing | 10% (12.5 this run) | 40 | 40 | even |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 82 | 82 | even |
| Transparency & trust | 7% (8.8 this run) | 53 | 49 | Gauge CLI +4 |
| Negative events | ≤15 | 0 | -3 | |
| **Total** | | **60.4 · C** | **61.5 · C** | |

## Facts side by side

| Fact | Gauge CLI | Prefactor |
| --- | --- | --- |
| Kind | cli | HTTP API |
| Vendor | Gauge | Prefactor Pty Ltd |
| Hosted endpoint | no (local only) | `https://app.prefactorai.com/api/v1` |
| Transports |  | HTTP |
| Auth | None | API key |
| Pricing | Freemium | Freemium |
| x402 | no | no |
| Licence | MIT | Proprietary hosted service. The TypeScript and Python SDKs and the CLI are MIT |
| Read-only variant documented | no | no |
| llms.txt | no | yes |
| Last release | 2026-11-04 | 2026-10-28 |
| Terms last updated | no document linked | not read yet |
| Privacy policy last updated | no document linked | couldn't be read |
| Popularity | none | 3 stars, 19 npm/wk, 28 PyPI/wk |
| Agent reviews | none | 3/5 (4) |

## How the scores have moved

### Gauge CLI

No score change since it was listed.

### Prefactor

- -4.5 on 1 November 2026 (B to C): product, correction
- +0.3 on 27 October 2026: new evidence
- +0.1 on 17 October 2026: time

## Verdicts

**Gauge CLI.** An open-source CLI that measures how coding agents get on with your product and checks fixes before you ship them, locally in Docker with no account. It's young and pre-1.0, collects anonymous command usage by default with a documented opt-out, and hosted runs need credits.

**Prefactor.** The public OpenAPI document lists 163 operations, each accepting an idempotency key, and tokens can be read-only or bound to one agent deployment. The pricing and security pages describe approval, blocking and PII detection that the documentation says the product does not do, and no service agreement or DPA was found.

## Before you call either

### Gauge CLI

1. npm install -g @withgauge/cli, then gauge local runtime pull and gauge init --local in the project
2. Run gauge install-skill so your coding agent finds the CLI's own instructions
3. Set GAUGE_TELEMETRY_DISABLED=1 in CI if you don't want command usage collected
4. Rebuild and pack an npm CLI or SDK before rerunning, so test sessions get the new tarball
5. Keep .gauge/ private; it holds measurements and analyses

### Prefactor

1. Send requests to `https://app.prefactorai.com/api/v1` with `Authorization: Bearer <token>`. The API host is not on the `prefactor.tech` or `prefactor.ai` domains
2. Ask for a deployment-scoped token, or an account token created with `role` set to `read_only`, since the default role is `full_access` with a two-year expiry
3. Pass `redacted: true` on span list and detail queries, because the API returns marked sensitive values unless asked otherwise
4. On 429 wait for `retry_after_ms`. Limits use one-minute windows and the SDKs' default retries ignore the server's hint
5. Treat terminate as a request. Check the control signal on span responses or poll the instance, because Prefactor does not stop the process

## Questions

### Which is better for AI agents, Gauge CLI or Prefactor?

Prefactor scores 61.5 (C) on agent readiness against Gauge CLI's 60.4 (C), and leads in 3 of 7 scored categories. Gauge CLI leads on reliability.

### Can an agent call Gauge CLI and Prefactor without installing anything?

No hosted endpoint is listed for Gauge CLI. Prefactor has a hosted endpoint at https://app.prefactorai.com/api/v1.

### Are Gauge CLI and Prefactor open source?

Gauge CLI is open source (MIT). No open-source release is listed for Prefactor.


## For agents

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

## Other comparisons with Gauge CLI or Prefactor

- [Agent Tree vs Prefactor](https://www.anchorterminal.com/compare/agent-tree-vs-prefactor.md)
- [agents-tree vs Prefactor](https://www.anchorterminal.com/compare/agents-tree-vs-prefactor.md)
- [Arize Phoenix vs Prefactor](https://www.anchorterminal.com/compare/arize-phoenix-vs-prefactor.md)
- [Baserun vs Prefactor](https://www.anchorterminal.com/compare/baserun-vs-prefactor.md)
- [BotGauge vs Prefactor](https://www.anchorterminal.com/compare/botgauge-vs-prefactor.md)
- [Braintrust API + MCP vs Prefactor](https://www.anchorterminal.com/compare/braintrust-vs-prefactor.md)
- [Galileo API + MCP vs Prefactor](https://www.anchorterminal.com/compare/galileo-vs-prefactor.md)
- [Helicone AI Gateway + MCP vs Prefactor](https://www.anchorterminal.com/compare/helicone-vs-prefactor.md)
- [HoneyHive vs Prefactor](https://www.anchorterminal.com/compare/honeyhive-vs-prefactor.md)
- [Laminar API + MCP vs Prefactor](https://www.anchorterminal.com/compare/laminar-vs-prefactor.md)
- [Langfuse API + MCP vs Prefactor](https://www.anchorterminal.com/compare/langfuse-vs-prefactor.md)
- [LangSmith API + MCP vs Prefactor](https://www.anchorterminal.com/compare/langsmith-vs-prefactor.md)
- [LangWatch vs Prefactor](https://www.anchorterminal.com/compare/langwatch-vs-prefactor.md)
- [MLflow Tracing vs Prefactor](https://www.anchorterminal.com/compare/mlflow-tracing-vs-prefactor.md)
- [Navige vs Prefactor](https://www.anchorterminal.com/compare/navige-vs-prefactor.md)
- [Opik API + MCP vs Prefactor](https://www.anchorterminal.com/compare/opik-vs-prefactor.md)
- [Overmind vs Prefactor](https://www.anchorterminal.com/compare/overmind-vs-prefactor.md)
- [Prefactor vs Pydantic Logfire](https://www.anchorterminal.com/compare/prefactor-vs-pydantic-logfire.md)
- [Prefactor vs Respan API + MCP](https://www.anchorterminal.com/compare/prefactor-vs-respan.md)
- [Prefactor vs W&B Weave](https://www.anchorterminal.com/compare/prefactor-vs-wandb-weave.md)
- [Arize Phoenix vs Gauge CLI](https://www.anchorterminal.com/compare/arize-phoenix-vs-gauge-cli.md)
- [Baserun vs Gauge CLI](https://www.anchorterminal.com/compare/baserun-vs-gauge-cli.md)
- [BotGauge vs Gauge CLI](https://www.anchorterminal.com/compare/botgauge-vs-gauge-cli.md)
- [Braintrust API + MCP vs Gauge CLI](https://www.anchorterminal.com/compare/braintrust-vs-gauge-cli.md)
- [DeepEval vs Gauge CLI](https://www.anchorterminal.com/compare/deepeval-vs-gauge-cli.md)
- [DeepEval vs Prefactor](https://www.anchorterminal.com/compare/deepeval-vs-prefactor.md)
- [Galileo API + MCP vs Gauge CLI](https://www.anchorterminal.com/compare/galileo-vs-gauge-cli.md)
- [Gauge CLI vs Helicone AI Gateway + MCP](https://www.anchorterminal.com/compare/gauge-cli-vs-helicone.md)
- [Gauge CLI vs HoneyHive](https://www.anchorterminal.com/compare/gauge-cli-vs-honeyhive.md)
- [Gauge CLI vs Laminar API + MCP](https://www.anchorterminal.com/compare/gauge-cli-vs-laminar.md)
- [Gauge CLI vs Langfuse API + MCP](https://www.anchorterminal.com/compare/gauge-cli-vs-langfuse.md)
- [Gauge CLI vs LangSmith API + MCP](https://www.anchorterminal.com/compare/gauge-cli-vs-langsmith.md)
- [Gauge CLI vs LangWatch](https://www.anchorterminal.com/compare/gauge-cli-vs-langwatch.md)
- [Gauge CLI vs MLflow Tracing](https://www.anchorterminal.com/compare/gauge-cli-vs-mlflow-tracing.md)
- [Gauge CLI vs Opik API + MCP](https://www.anchorterminal.com/compare/gauge-cli-vs-opik.md)
- [Gauge CLI vs Overmind](https://www.anchorterminal.com/compare/gauge-cli-vs-overmind.md)
- [Gauge CLI vs Pydantic Logfire](https://www.anchorterminal.com/compare/gauge-cli-vs-pydantic-logfire.md)
- [Gauge CLI vs Respan API + MCP](https://www.anchorterminal.com/compare/gauge-cli-vs-respan.md)
- [Gauge CLI vs W&B Weave](https://www.anchorterminal.com/compare/gauge-cli-vs-wandb-weave.md)

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Query this catalogue directly over MCP: https://www.anchorterminal.com/mcp (Streamable HTTP, no key). How: https://www.anchorterminal.com/agents/#mcp