# OpenRouter API: Fusion analyst_model, Guardrail model-training flags, WebSearch blocked_domains

> OpenRouter shipped API schema updates including one breaking change: FusionCallAnalysisInProgressEvent gained a required analyst_model property (judge_model retained as deprecated alias). New Guardrail properties enable_free_model_publication, enable_free_model_training, and enable_paid_model_training were added. AutoBetaRouterPlugin gained a cost_tier property. WebSearchDomainFilter gained blocked_domains. The responses OpenAPI tag was renamed to Responses (documentation-grouping only, no SDK or endpoint changes).

| | |
|---|---|
| **Tool** | openrouter |
| **Version** | — |
| **Kind** | announcement |
| **Published** | 2026-07-28 |
| **Observed** | 2026-08-21 |
| **Significance** | 3/5 |
| **Breaking** | yes |
| **Categories** | api-change, breaking |

## What changed


### Breaking
- `FusionCallAnalysisInProgressEvent`: required `analyst_model` property added. `judge_model` retained as deprecated alias.
- `$.tags: responses` renamed to `Responses` (documentation-grouping only; no SDK or endpoint URL changes).

### Schema changes
- Guardrail schemas (CreateGuardrailRequest, Guardrail, UpdateGuardrailRequest): new properties `enable_free_model_publication`, `enable_free_model_training`, `enable_paid_model_training`.
- AutoBetaRouterPlugin: new property `cost_tier`.
- WebSearchDomainFilter: new property `blocked_domains`.
- FusionServerToolConfig: `effort` and `max_tokens` properties updated.
- GenerationResponse: `data_region` property updated.
- Multiple schema descriptions updated (FusionAnalysisResult, FusionCallAnalysisCompletedEvent, FusionCallAnalysisInProgressEvent, FusionPlugin, FusionServerToolConfig, FusionServerTool_OpenRouter, FusionSource, OutputFusionServerToolItem, ChatWebSearchShorthand, WebSearchConfig, WebSearchServerToolConfig).
- File endpoints: response schemas and parameter descriptions updated.
- Various examples modified.


## Sources

- [blog_rss](https://openrouter.ai/docs/changelog#july-28-2026) — retrieved 2026-08-21


## Community

_No curated reactions recorded. Facts and community takes are kept in separate layers
and never blended._

---
Canonical: https://changelogs.info/openrouter/openrouter-api-fusion-analyst-model-guardrail-model-training-flags-websearch-blo
Entity: https://changelogs.info/openrouter
Event ID: `evt_2026-07-28_openrouter_july-28-2026`
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