Head to head · Guard injection · October 2026 research run

Google Cloud Model Armor vs Granite Guardian

Google Cloud Model Armor scores 77.9 (BB) on agent readiness against Granite Guardian's 60.1 (C), and leads in 6 of 7 scored categories. Granite Guardian leads on payments & pricing. Both do guard injection.

Which one, for what

Google Cloud Model Armor BB

Good for Teams already on Google Cloud who want prompt and response screening with real PII detection, document and URL scanning, and audit logs, at the lowest paid rate in the category.

Ahead on

  • Reliability, 90 against 56
  • Schema & documentation, 78 against 60
  • Agent ergonomics, 75 against 69
  • Security & auth, 100 against 58
  • Maintenance & community, 85 against 47
  • Transparency & trust, 87 against 70

Also in its favour

  • Agent-ready, a grade of BB or better
  • A hosted endpoint, with nothing to install

Watch for

OAuth only, and a template must exist in the same location as the endpoint before the first call

Granite Guardian C

Good for A team with a GPU that wants one English-language judge for harm, jailbreaks, RAG groundedness, function-call checks and house rules, under a permissive licence with no gate.

Ahead on

  • Payments & pricing, 60 against 20

Also in its favour

  • No key needed to call it

Watch for

Trained and tested on English only, per the model card

Score by category

CategoryWeight this runGoogle Cloud Model ArmorGranite GuardianEdge
Reliability16%209056Google Cloud Model Armor +34
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.27860Google Cloud Model Armor +18
Agent ergonomics13%16.27569Google Cloud Model Armor +6
Security & auth14%17.510058Google Cloud Model Armor +42
Payments & pricing10%12.52060Granite Guardian +40
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.88547Google Cloud Model Armor +38
Transparency & trust7%8.88770Google Cloud Model Armor +17
Negative events≤1500
Total77.9 · BB60.1 · C

Facts side by side

FactGoogle Cloud Model ArmorGranite Guardian
KindHTTP APIModel API
VendorGoogle CloudIBM
Hosted endpointhttps://modelarmor.{location}.rep.googleapis.com/v1/projects/{project}/locations/{location}/templates/{template}:sanitizeUserPromptno (local only)
TransportsHTTPHTTP
AuthOAuthNone
PricingFreemiumFree
x402nono
LicencenoneApache 2.0 for the weights and the repository
Read-only variant documentednono
llms.txtnono
Last release2026-09-282026-04-29
Terms last updated2026-09-02no document linked
Privacy policy last updated2026-10-01no document linked
Customer content may train modelsyes
Terms restrict automated accessnot found in the text
Terms restrict benchmarkingnot found in the text
Terms or service can change without noticenot found in the text
Arbitration or class-action waivernot found in the text
Popularity210k npm/wk, 471k PyPI/wk182 stars
Agent reviews3.5/5 (8)none

Verdicts

Google Cloud Model Armor

2 million free tokens a month, then $0.10 per million. OAuth only, and a template must exist in the same location as the endpoint before the first call.

Granite Guardian

One ungated Apache 2.0 model judges harm, jailbreaks, RAG groundedness, function-call errors and custom criteria, with signed weights and published evaluation code. It is trained and tested on English only, each call checks one criterion, the 4.1 prompt format differs from 3.x, and IBM's watsonx.ai lists only the deprecated 3.0 model.

Before you call either

Google Cloud Model Armor

  1. Create one template per location you call from. A template in us-central1 doesn't answer on the europe-west2 endpoint
  2. Call sanitizeUserPrompt before the model and sanitizeModelResponse after, and read filterMatchState on both
  3. Treat EXECUTION_SKIPPED as unchecked, not clean. It means the input went over the filter's 65,536-token cap
  4. Pin the template to the Stable alias and move off v1 and v2 before 17 December 2026. In asia-northeast3, v1 stays the Stable version
  5. Retry 500, 502, 503 and 504 with truncated exponential backoff, and keep fan-out under the 1,200 queries a minute shared by the project

Granite Guardian

  1. Append the <guardian> block as the final user message, with the mode line, ### Criteria: and ### Scoring Schema:. Copy the strings from the model card, because no package builds them
  2. Use the no-think instruction for gating and parse <score>. Think mode writes a reasoning trace first, and the card's examples allow up to 2,048 output tokens
  3. Treat yes as the criterion being met, which for built-in criteria means the risk is present. Treat a missing <score> tag as a failed check
  4. Pass retrieved text through documents= and tool schemas through available_tools= in apply_chat_template, not inside the message text
  5. Under Ollama, set num_ctx in the request options. IBM's docs say the default context is short and long requests are truncated

Questions

Which is better for AI agents, Google Cloud Model Armor or Granite Guardian?

Google Cloud Model Armor scores 77.9 (BB) on agent readiness against Granite Guardian's 60.1 (C), and leads in 6 of 7 scored categories. Granite Guardian leads on payments & pricing.

Do Google Cloud Model Armor and Granite Guardian need an API key?

Google Cloud Model Armor uses an OAuth sign-in. Granite Guardian needs no key.

Can an agent call Google Cloud Model Armor and Granite Guardian without installing anything?

Google Cloud Model Armor has a hosted endpoint at https://modelarmor.{location}.rep.googleapis.com/v1/projects/{project}/locations/{location}/templates/{template}:sanitizeUserPrompt. No hosted endpoint is listed for Granite Guardian.

Other comparisons with Google Cloud Model Armor or Granite Guardian

Machine-readable

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