# Guardrails AI vs Mistral Moderation API

> Mistral Moderation API has a score of 58.6 (C) against Guardrails AI's 49.8 (D). Both do guard moderation. The largest gap is schema & documentation, 26 points. Category scores, facts, verdicts and agent notes side by side.

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- Slim: https://www.anchorterminal.com/compare/guardrails-ai-vs-mistral-moderation.min.md (~380 tokens, same facts, less prose, for token-sensitive contexts)
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- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- Updated: 2026-10-05

Mistral Moderation API has a score of 58.6 (C) against Guardrails AI's 49.8 (D). Both do guard moderation. The largest gap is schema & documentation, 26 points.

- Guardrails AI: grade D, 49.8/100, rank #366 of 452. Markdown https://www.anchorterminal.com/tools/guardrails-ai.md · JSON https://www.anchorterminal.com/api/v1/tools/guardrails-ai.json
- Mistral Moderation API: grade C, 58.6/100, rank #278 of 452. Markdown https://www.anchorterminal.com/tools/mistral-moderation.md · JSON https://www.anchorterminal.com/api/v1/tools/mistral-moderation.json

## Which one, for what

Pick Guardrails AI for reliability (+18), payments & pricing (+20), maintenance & community (+11).

Pick Mistral Moderation API for schema & documentation (+26), agent ergonomics (+12), security & auth (+10), transparency & trust (+22).

## Score by category

| Category | Weight | Guardrails AI | Mistral Moderation API | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 58 | 40 | Guardrails AI +18 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 59 | 85 | Mistral Moderation API +26 |
| Agent ergonomics | 13% (16.2 this run) | 63 | 75 | Mistral Moderation API +12 |
| Security & auth | 14% (17.5 this run) | 44 | 54 | Mistral Moderation API +10 |
| Payments & pricing | 10% (12.5 this run) | 60 | 40 | Guardrails AI +20 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 44 | 33 | Guardrails AI +11 |
| Transparency & trust | 7% (8.8 this run) | 61 | 83 | Mistral Moderation API +22 |
| Negative events | ≤15 | -6 | 0 | |
| **Total** | | **49.8 · D** | **58.6 · C** | |

## Facts side by side

| Fact | Guardrails AI | Mistral Moderation API |
| --- | --- | --- |
| Kind | Agent framework | HTTP API |
| Vendor | Guardrails AI (Harvey) | Mistral AI |
| Hosted endpoint | no (local only) | `https://api.mistral.ai/v1/moderations` |
| Transports | HTTP | HTTP |
| Auth | None | API key |
| Pricing | Free | Free |
| x402 | no | no |
| Licence | Apache-2.0 | none |
| Tools exposed | none | none |
| Context cost (tools/list) | n/a | n/a |
| p95 latency | not measured yet | not measured yet |
| Availability (30d) | not measured yet | not measured yet |
| Read-only variant documented | no | no |
| llms.txt | no | yes |
| MCP registry | not listed | not listed |
| Last release | 2026-08-14 | 2026-03-01 |
| Popularity | 7.3k stars, 81 npm/wk, 32k PyPI/wk | 769 stars, 8.4M npm/wk, 3.7M PyPI/wk |
| Agent reviews | 2/5 (2) | 3/5 (2) |

## Verdicts

**Guardrails AI.** Validators have configurable actions for failed checks. Harvey acquired the company on 9 September 2026; the reviewed announcement did not state plans for the library.

**Mistral Moderation API.** Free, on the same key as the rest of the Mistral API, and the Experiment plan needs no card. No moderation component on the status page and no readable incident history.

## Before you call either

### Guardrails AI

1. Pin guardrails-ai==0.11.0 and each guardrails-ai-<validator> package, install only from PyPI, and never install 0.10.1
2. Import validators from guardrails_ai.<name>, not guardrails.hub, and don't run guardrails hub install
3. Pass use_local=True to detect_pii, toxic_language and the other model-backed validators, or set validation_endpoint to a server you run
4. Set enable_metrics to false in ~/.guardrailsrc if you don't want usage metrics sent
5. Avoid building on reask and RAIL. The open 1.0.0 issues plan to remove both

### Mistral Moderation API

1. Use /v1/chat/moderations with the full message list when checking an assistant reply. The raw endpoint has no context
2. Read category_scores and set your own threshold per category. The booleans use Mistral's cut-offs
3. Pin mistral-moderation-2603. The 2411 model was retired on 31 March 2026
4. Move to a paid workspace or zero retention if the text you screen shouldn't train models
5. For a Mistral-hosted agent, set the moderation_llm_v2 guardrail with block_on_error true and skip the separate call

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