# Regulus agent integration guide

## Access order

1. Use the Streamable HTTP MCP server at https://regulus.evalyn.ai/mcp when your client supports MCP.
2. Otherwise use the read-only Markdown API below. Markdown is the default response format; append format=json for JSON.
3. Use normal webpage URLs only for human navigation.

No authentication is currently required. Public traffic is rate limited. Cache results locally, avoid parallel duplicate requests, and honor HTTP 429 and Retry-After.

## Recommended research workflow

1. Search for relevant authorities.
2. Retrieve the complete controlling document.
3. Retrieve focused passages for exact support.
4. Inspect hierarchy for scope and definitions.
5. Inspect related material for guidance, interpretations, enforcement application, amendments, and supersession.
6. State uncertainty and distinguish binding authority from nonbinding material.

## Markdown API

- Search: GET https://regulus.evalyn.ai/api/llm/search?q=SCADA+testing&limit=10
- Document: GET https://regulus.evalyn.ai/api/llm/document?identifier=49+CFR+192.631&max_characters=30000
- Stable JSON alias: GET https://regulus.evalyn.ai/document/49-cfr-192-631.json
- Stable Markdown alias: GET https://regulus.evalyn.ai/document/49-cfr-192-631.md
- Passages: GET https://regulus.evalyn.ai/api/llm/passages?identifier=49+CFR+192.631&q=testing&limit=8
- Related authorities: GET https://regulus.evalyn.ai/api/llm/related?identifier=49+CFR+192.631&limit=25
- Hierarchy: GET https://regulus.evalyn.ai/api/llm/hierarchy?identifier=49+CFR+192.631
- Corpus status: GET https://regulus.evalyn.ai/api/llm/status

Parameters must be URL encoded. Search limit is at most 25, passage limit 15, related limit 50, query length 1,000 characters, and document output 40,000 characters. Responses indicate when document text was truncated.

Document webpages advertise both stable aliases with HTML alternate links. Use the aliases when a slug is already known; use the API document operation when resolving a citation or choosing a shorter output limit.

## MCP tools

- search_regulatory_corpus
- get_regulatory_document
- get_document_passages
- get_related_authorities
- get_document_hierarchy
- get_corpus_status

All tools are read-only. Search uses OpenSearch and exact records are hydrated from PostgreSQL.

## Evidence and citation policy

- Search excerpts locate evidence but are not themselves authority.
- Prefer current regulations for legal requirements.
- Treat guidance, FAQs, interpretations, inspections, permits, enforcement actions, incidents, and NTSB materials according to their actual authority and context.
- Cite source_url as the primary citation and app_url as a navigation link.
- Check status and effective_on before describing a provision as current.
- Use hierarchy to establish title, part, subpart, and sibling context.
- Explain the reasoning chain and identify conflicting or incomplete evidence.