# 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. Category scores, facts, verdicts and agent notes side by side.

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- Updated: 2026-10-09

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 Guardian: grade C, 60.1/100, rank #478 of 842. Markdown https://www.anchorterminal.com/tools/granite-guardian.md · JSON https://www.anchorterminal.com/api/v1/tools/granite-guardian.json
- OpenAI Guardrails: grade B, 69.5/100, rank #175 of 842. Markdown https://www.anchorterminal.com/tools/openai-guardrails.md · JSON https://www.anchorterminal.com/api/v1/tools/openai-guardrails.json

## 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

| Category | Weight | Granite Guardian | OpenAI Guardrails | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 56 | 73 | OpenAI Guardrails +17 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 60 | 66 | OpenAI Guardrails +6 |
| Agent ergonomics | 13% (16.2 this run) | 69 | 73 | OpenAI Guardrails +4 |
| Security & auth | 14% (17.5 this run) | 58 | 59 | OpenAI Guardrails +1 |
| Payments & pricing | 10% (12.5 this run) | 60 | 60 | even |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 47 | 89 | OpenAI Guardrails +42 |
| Transparency & trust | 7% (8.8 this run) | 70 | 76 | OpenAI Guardrails +6 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **60.1 · C** | **69.5 · B** | |

## Facts side by side

| Fact | Granite Guardian | OpenAI Guardrails |
| --- | --- | --- |
| Kind | Model API | Agent framework |
| Vendor | IBM | OpenAI |
| Hosted endpoint | no (local only) | no (local only) |
| Transports | HTTP | HTTP |
| Auth | None | API key |
| Pricing | Free | Free |
| x402 | no | no |
| Licence | Apache 2.0 for the weights and the repository | MIT |
| Read-only variant documented | no | no |
| llms.txt | no | no |
| Last release | 2026-04-29 | 2026-09-10 |
| Terms last updated | no document linked | no document linked |
| Privacy policy last updated | no document linked | no 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 |  |  |
| Popularity | 182 stars | 259 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).


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/granite-guardian-vs-openai-guardrails.json, and with the fewest tokens: https://www.anchorterminal.com/compare/granite-guardian-vs-openai-guardrails.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "granite-guardian", "b": "openai-guardrails"}`. From a terminal: `anchor compare granite-guardian openai-guardrails`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/granite-guardian.json and https://www.anchorterminal.com/api/v1/tools/openai-guardrails.json

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