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Head to head · Guard moderation · October 2026 research run

Granite Guardian vs OpenAI Guardrails

OpenAI Guardrails scores 69.5 (B) on agent readiness against Granite Guardian's 60.1 (C), and leads in 6 of 7 scored categories. Both do guard moderation.

Granite GuardianIBM · Model API C60.1/100#478 of 841 OpenAI GuardrailsOpenAI · Agent framework B69.5/100#175 of 841

Which one, for what

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.

Also in its favour

  • No key needed to call it

Watch for

Trained and tested on English only, per the model card

OpenAI Guardrails B

Good for Teams already on the OpenAI client or Agents SDK that want several checks from one config file with little code.

Ahead on

  • Reliability, 73 against 56
  • Schema & documentation, 66 against 60
  • Maintenance & community, 89 against 47
  • Transparency & trust, 76 against 70

Also in its favour

  • Open source

Watch for

By default a check that fails to run returns tripwire_triggered=False, so the request continues. Strict mode is opt-in

Score by category

CategoryWeight this runGranite GuardianOpenAI GuardrailsEdge
Reliability16%205673OpenAI Guardrails +17
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.26066OpenAI Guardrails +6
Agent ergonomics13%16.26973OpenAI Guardrails +4
Security & auth14%17.55859OpenAI Guardrails +1
Payments & pricing10%12.56060even
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.84789OpenAI Guardrails +42
Transparency & trust7%8.87076OpenAI Guardrails +6
Negative events≤1500
Total60.1 · C69.5 · B

Facts side by side

FactGranite GuardianOpenAI Guardrails
KindModel APIAgent framework
VendorIBMOpenAI
Hosted endpointno (local only)no (local only)
TransportsHTTPHTTP
AuthNoneAPI key
PricingFreeFree
x402nono
LicenceApache 2.0 for the weights and the repositoryMIT
Read-only variant documentednono
llms.txtnono
Last release2026-04-292026-09-10
Terms last updatedno document linkedno document linked
Privacy policy last updatedno document linkedno document linked
Customer content may train models
Terms restrict automated access
Terms restrict benchmarking
Terms or service can change without notice
Arbitration or class-action waiver
Popularity182 stars259 stars, 19k npm/wk, 105k PyPI/wk

Verdicts

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.

OpenAI Guardrails

MIT-licensed wrapper that adds twelve configurable checks to OpenAI client calls from one JSON file, with tool-level injection checks for the Agents SDK. The README labels it a preview at version 0.3.3, and by default a check that fails to run is reported as passed unless raise_guardrail_errors=True is set.

Before you call either

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

OpenAI Guardrails

  1. Pass raise_guardrail_errors=True to the client. The default treats a check that failed to run as passed
  2. Run python -m spacy download en_core_web_sm before using Contains PII, or client initialisation fails
  3. Catch GuardrailTripwireTriggered, and append a user message to history only after the call returns without it
  4. Use block=true for Contains PII in the output stage. Masking works only in the pre-flight stage
  5. Keep stream=False where output must be checked before it is shown, and budget one extra model call per LLM-based check

Questions

Which is better for AI agents, Granite Guardian or OpenAI Guardrails?

OpenAI Guardrails scores 69.5 (B) on agent readiness against Granite Guardian's 60.1 (C), and leads in 6 of 7 scored categories.

Can an agent call Granite Guardian and OpenAI Guardrails without installing anything?

No hosted endpoint is listed for Granite Guardian. No hosted endpoint is listed for OpenAI Guardrails.

Are Granite Guardian and OpenAI Guardrails open source?

No open-source release is listed for Granite Guardian. OpenAI Guardrails is open source (MIT).

Other comparisons with Granite Guardian or OpenAI Guardrails

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