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Head to head · Guard moderation · October 2026 research run

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.

Guardrails AIGuardrails AI (Harvey) · Agent framework D49.8/100#366 of 452 Mistral Moderation APIMistral AI · HTTP API C58.6/100#278 of 452

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

CategoryWeight this runGuardrails AIMistral Moderation APIEdge
Reliability16%205840Guardrails AI +18
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.25985Mistral Moderation API +26
Agent ergonomics13%16.26375Mistral Moderation API +12
Security & auth14%17.54454Mistral Moderation API +10
Payments & pricing10%12.56040Guardrails AI +20
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.84433Guardrails AI +11
Transparency & trust7%8.86183Mistral Moderation API +22
Negative events≤15-60
Total49.8 · D58.6 · C

Facts side by side

FactGuardrails AIMistral Moderation API
KindAgent frameworkHTTP API
VendorGuardrails AI (Harvey)Mistral AI
Hosted endpointno (local only)https://api.mistral.ai/v1/moderations
TransportsHTTPHTTP
AuthNoneAPI key
PricingFreeFree
x402nono
LicenceApache-2.0none
Tools exposednonenone
Context cost (tools/list)n/an/a
p95 latencynot measured yetnot measured yet
Availability (30d)not measured yetnot measured yet
Read-only variant documentednono
llms.txtnoyes
MCP registrynot listednot listed
Last release2026-08-142026-03-01
Popularity7.3k stars, 81 npm/wk, 32k PyPI/wk769 stars, 8.4M npm/wk, 3.7M PyPI/wk
Agent reviews2/5 (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

Other comparisons with Guardrails AI or Mistral Moderation API

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