> ## Documentation Index
> Fetch the complete documentation index at: https://learn.orbexa.io/llms.txt
> Use this file to discover all available pages before exploring further.

# OTR protocol technical reference

> Complete technical reference for the OTR protocol — full signal inventory, weight tables, status codes, error codes, and version changelog.

# Reference

## 13.1 Weight Tables

### COLD Ecommerce (Default for E-commerce Sites)

```
Trust Score = V x 0.40 + S x 0.15 + G x 0.20 + T x 0.10 + D x 0.15
```

| Dimension        | Weight         | Signal Count                     |
| ---------------- | -------------- | -------------------------------- |
| V — Verification | 40%            | 13                               |
| S — Security     | 15%            | 15                               |
| G — Governance   | 20%            | 10                               |
| T — Transparency | 10%            | 18                               |
| D — Data Quality | 15%            | 21 (including 4 penalty signals) |
| F — Fulfillment  | 0% (COLD mode) | Requires authorization           |
| **Total**        | **100%**       | **77**                           |

### COLD SaaS (For SaaS/Software Sites)

```
Trust Score = V x 0.37 + S x 0.20 + G x 0.23 + T x 0.15 + D x 0.05
```

| Dimension        | Weight | Note                                                  |
| ---------------- | ------ | ----------------------------------------------------- |
| V — Verification | 37%    |                                                       |
| S — Security     | 20%    | Higher (security is core to SaaS trust)               |
| G — Governance   | 23%    | Higher (B2B compliance)                               |
| T — Transparency | 15%    | Higher (SLA/uptime expected)                          |
| D — Data Quality | 5%     | Uses specialized SaaS D-signals (16 signals, see Ch5) |
| F — Fulfillment  | 0%     |                                                       |

### AUTH Mode (Authorized Merchants)

```
Trust Score = V x 0.10 + S x 0.10 + G x 0.10 + T x 0.05 + D x 0.25 + F x 0.40
```

| Dimension        | Weight | Note                           |
| ---------------- | ------ | ------------------------------ |
| V — Verification | 10%    | Identity already verified      |
| S — Security     | 10%    | Baseline check                 |
| G — Governance   | 10%    | Baseline check                 |
| T — Transparency | 5%     |                                |
| D — Data Quality | 25%    | Merchant provides richer data  |
| F — Fulfillment  | 40%    | Actual transaction performance |

## 13.2 Trust Badge Thresholds

| Badge    | Score Range |
| -------- | ----------- |
| PLATINUM | 90-100      |
| GOLD     | 80-89       |
| SILVER   | 70-79       |
| BRONZE   | 60-69       |
| UNRATED  | 0-59        |

## 13.3 Signal Status Semantics

| Status         | Meaning                                | Impact on Score                 |
| -------------- | -------------------------------------- | ------------------------------- |
| `detected`     | Signal is present and verified         | Positive contribution           |
| `not_found`    | Scanned but signal is absent           | No contribution or penalty      |
| `not_scanned`  | Signal has not been scanned yet        | Excluded from score calculation |
| `fetch_failed` | Scan failed (timeout or network error) | Excluded from score calculation |

## 13.4 Data Sources

| Data Source     | Purpose                             | Affected Dimensions |
| --------------- | ----------------------------------- | ------------------- |
| SSL/TLS         | Certificate verification            | V                   |
| WHOIS           | Domain registration information     | V                   |
| DNS             | Security record checks              | S                   |
| GLEIF           | Legal entity verification           | V, G                |
| Wikidata        | Public knowledge verification       | V                   |
| Finnhub         | Public company verification         | V, G                |
| SEC EDGAR       | US public company filings           | G                   |
| Google WebRisk  | Malicious domain detection          | V                   |
| OpenFIGI        | Financial instrument identification | G                   |
| HTML crawl      | Page content analysis               | T, D                |
| JSON-LD parsing | Structured data inspection          | D                   |

## 13.5 API Error Codes

| HTTP Status | Meaning                          |
| ----------- | -------------------------------- |
| 200         | Success                          |
| 404         | Domain not found (never scanned) |
| 429         | Rate limit exceeded              |
| 500         | Internal server error            |

## 13.6 Scan Frequency

| Type            | Frequency                                     |
| --------------- | --------------------------------------------- |
| Initial scan    | Triggered immediately upon request            |
| Periodic rescan | Automatic, based on temporal staleness policy |
| Manual trigger  | Via the verify page                           |

## 13.7 Open-Source Resources

| Resource                   | URL                                                                                                               |
| -------------------------- | ----------------------------------------------------------------------------------------------------------------- |
| OTR Protocol Specification | [github.com/yb48666-ctrl/OTR-Protocol-by-orbexa](https://github.com/yb48666-ctrl/OTR-Protocol-by-orbexa)          |
| API Documentation          | This chapter + [Chapter 6: REST API](/en/book-2/ch6-rest-api) + [Chapter 8: OpenAPI](/en/book-2/ch8-openapi-spec) |
| MCP Server                 | [Chapter 7](/en/book-2/ch7-mcp-server)                                                                            |

***

Congratulations on completing Book 2. You now have a thorough understanding of the OTR protocol's technical foundations.

**Recommended next steps**:

* Learn about commerce protocols: [Book 3: UCP](/en/book-3/index) / [Book 4: ACP](/en/book-4/index) / [Book 5: MCP](/en/book-5/index)
* Optimize your AI visibility: [Book 6: SEO for AI](/en/book-6/index)
* Use ready-made templates: [Templates and Prompts](/en/templates/index)
* Look up terminology: [Glossary](/en/glossary/index)

***

**Recommended next**: [UCP — Universal Commerce Protocol](/en/book-3/index) — Learn how AI agents conduct standardized commerce interactions with merchants