Azure AI Content Safety (Prompt Shields) vs Mistral Moderation API

Azure AI Content Safety (Prompt Shields)

Prompt Shields checks up to five retrieved documents for indirect injection, not only the user prompt. Needs an Azure subscription with a card, a resource and a region that has the feature, before the first call.

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.

Azure AI Content Safety (Prompt Shields)

1. Send retrieved pages and tool results in the documents array of shieldPrompt, not in userPrompt, so document attacks are reported separately
2. Call text:shieldPrompt over REST with api-version=2024-09-01. The Python SDK 1.0.0 has no method for it
3. Keep each request under 10,000 characters across prompt and documents, and split long tool results
4. Create the resource in a region that lists Prompt Shields, since not every region has it
5. On F0 you get 5 requests a second. Queue checks or move to S0 before load testing

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