Supergood | Lexis+ Tax API
Programmatically access Lexis+ Tax research content, Shepard’s/citator signals, state-and-local tax comparison charts, and change alerts with a stable REST API. Supergood builds and operates production-grade, unofficial Lexis+ Tax integrations so your team can automate compliance intelligence and audit workflows without heavy custom engineering.
Plain English: Lexis+ Tax is a research platform from LexisNexis for tax professionals to find and analyze federal, state, and local tax law—statutes, regulations, IRS guidance, cases, and expert analysis—alongside tools like Shepard’s citator, Smart Charts for multistate comparisons, and real-time alerts. An unofficial API lets you programmatically search and retrieve authoritative documents, pull citator metadata, run cross-jurisdiction “smart chart” comparisons, and subscribe to alerts for topics or citations you monitor.
For a GRC, regtech, or audit-tech company integrating with Lexis+ Tax, this means you can ingest authoritative sources into your regulatory knowledge graph, map citations to controls and workpapers, automate change detection across jurisdictions, and embed multistate rule comparisons into your product. You can push client/matter tags for billing and evidence traceability, trigger downstream updates in ServiceNow GRC or Workiva, enrich AI copilots with grounded legal context, and keep policy logic synchronized with live primary law and agency guidance.
What is Lexis+ Tax?
Lexis+ Tax (https://www.lexisnexis.com/en-us/products/lexis-tax.page) is a cloud-based tax research solution that aggregates primary law and expert analysis across federal, state, and local jurisdictions. It provides access to the Internal Revenue Code, Treasury regulations, IRS administrative guidance (revenue rulings/procedures, notices, announcements, PLRs, CCA), federal and state case law, state statutes and regulations, agency materials, news (e.g., Law360), practical guidance, and tools such as Shepard’s and Smart Charts.
Core product areas include:
- Federal Tax Research (code, regs, IRS guidance, federal cases)
- State & Local Tax (SALT) Research (statutes, regs, administrative materials, cases)
- Citator & Validation (Shepard’s signals, citing references, history)
- Comparative Tools (Smart Charts and cross-state topic comparisons)
- News & Analysis (tax news, practice notes, treatises)
- Alerts & Monitoring (topic, citation, and document change alerts)
Common data entities:
- Documents (statutes, regulations, cases, IRS guidance, analysis, news)
- Citations & Citator Signals (Shepard’s indicators, history, citing references)
- Smart Chart Topics and Results (multistate comparisons by topic)
- Alerts & Saved Searches (query definitions, delivery settings)
- Users, Roles/Entitlements (access rights by content set)
- Client/Matter Tags, Folders, and Annotations (organization and billing)
The Lexis+ Tax Integration Challenge
Tax teams rely on Lexis+ Tax for daily research, but turning portal-based content and tools into automated, API-driven workflows is non-trivial:
- Entitlements & licensing: Access varies by subscription package and user role across content sets
- Citator complexity: Shepard’s indicators and citing references require careful normalization
- Interactive tools: Smart Charts and comparison workflows are optimized for front-end usage
- Authentication: SSO/MFA and session lifecycles complicate headless automation
- Heterogeneous content: Statutes, regs, cases, and guidance differ in structure, metadata, and versioning
- Change detection: Legislative and administrative updates require robust monitoring without over-polling
How Supergood Creates Lexis+ Tax APIs
Supergood reverse-engineers authenticated browser flows and network interactions to deliver a resilient API endpoint layer for your Lexis+ Tax tenant.
- Handles username/password, SSO/OAuth, and MFA (SMS, email, TOTP) securely
- Maintains session continuity with automated refresh and change detection
- Normalizes responses across document types, jurisdictions, and tools
- Respects customer entitlements and role-based permissions for compliant access
Use Cases
Regulatory Intel & Change Management
- Continuously monitor relevant topics (e.g., R&D amortization, bonus depreciation, sales tax nexus)
- Stream new and changed documents to your regulatory change management pipeline
- Trigger reviews, Jira tickets, or ServiceNow GRC tasks when signals or authorities change
Citation & Authority Traceability
- Retrieve documents and Shepard’s metadata to evidence controls and audit conclusions
- Map citations to specific procedures and retain linkbacks for re-verification
- Capture point-in-time snapshots for audit trails and client/matter billing
State & Local Tax Comparisons
- Generate Smart Charts for multistate topics (e.g., nexus thresholds, conformity, filing deadlines)
- Normalize outputs to populate policy engines and customer-facing guidance
- Keep chart results current with scheduled re-runs and diffing
Audit Evidence & Knowledge Management
- Ingest authoritative text and summaries into a knowledge graph or workpaper system (e.g., Workiva)
- Attach documents to engagements with client/matter tags for downstream reporting
- Power internal research bots with grounded references and citation context
Available Endpoints
Authentication
POST /sessions: Establish a session using credentials. Supergood manages MFA (SMS, email, TOTP) and SSO/OAuth when enabled. Returns a short-lived auth token maintained by the platform.
curl --request POST \
--url https://api.supergood.ai/integrations/<integration_id>/sessions \
--header 'Authorization: Basic <Base64 encoded token>' \
--header 'Content-Type: application/json' \
--data '{
"username": "[email protected]",
"password": "<password>",
"mfa": { "type": "totp", "code": "123456" }
}'
Example response
{
"authToken": "eyJhbGciOi...",
"expiresIn": 3600,
"user": {
"id": "u_lex_72a110",
"name": "Tax Researcher",
"entitlements": ["federal_tax", "state_local_tax", "analysis", "news", "smart_charts"]
}
}
POST /sessions/refresh: Refresh an existing token to keep sessions uninterrupted.
Document Search
GET /tax/documents: Search federal, state, and local tax materials with filters and summary details.
Query parameters
- query: string (Lucene-style search or natural language)
- jurisdictions: comma-separated codes (e.g., US-FED, CA, NY, TX)
- contentTypes: comma-separated values (statute | regulation | case | guidance | analysis | news)
- courtLevels: comma-separated values (tax_court | appellate | supreme | trial)
- shepardsSignal: positive | caution | negative | neutral
- fromDate, toDate: ISO 8601 dates
- sort: relevance | date_desc | date_asc
- page, pageSize: integers for pagination
Example request
curl --request GET \
--url 'https://api.supergood.ai/integrations/<integration_id>/tax/documents?query=section%20174%20amortization&jurisdictions=US-FED&contentTypes=statute,regulation,guidance,case&sort=relevance&page=1&pageSize=25' \
--header 'Authorization: Bearer <authToken>'
Example response
{
"items": [
{
"docId": "doc_usf_stat_26usc174",
"title": "26 U.S.C. § 174 — Research and experimental expenditures",
"citation": "26 U.S.C. § 174",
"contentType": "statute",
"jurisdiction": "US-FED",
"court": null,
"publishedDate": "1954-08-16",
"effectiveDate": "2022-01-01",
"shepardsSignal": "caution",
"summary": "Rules for amortization of specified research or experimental expenditures.",
"topics": ["federal_income_tax", "r_and_d"],
"updatedAt": "2026-01-20T13:45:00Z"
}
],
"page": 1,
"pageSize": 25,
"total": 137
}
Document Detail
GET /tax/documents/{docId}: Retrieve a document with normalized metadata, citator summary, related materials, and downloadable artifacts.
curl --request GET \
--url https://api.supergood.ai/integrations/<integration_id>/tax/documents/doc_usf_stat_26usc174 \
--header 'Authorization: Bearer <authToken>'
Example response
{
"docId": "doc_usf_stat_26usc174",
"title": "26 U.S.C. § 174 — Research and experimental expenditures",
"citation": "26 U.S.C. § 174",
"contentType": "statute",
"jurisdiction": "US-FED",
"text": "[truncated normalized text content]",
"html": "<section id=...>[redacted for brevity]</section>",
"publishedDate": "1954-08-16",
"effectiveDate": "2022-01-01",
"version": {
"asOf": "2026-01-01",
"source": "Lexis+ Tax"
},
"citator": {
"signal": "caution",
"history": [
{"type": "amended", "date": "2021-11-15", "note": "Amendments affecting amortization"}
],
"citingReferencesCount": 284,
"topCitingReferences": [
{"docId": "doc_usf_case_taxct_2023_abc", "title": "Tax Court Opinion", "citation": "T.C. 2023-XX"}
]
},
"related": [
{"docId": "doc_usf_reg_treas_1_174", "contentType": "regulation", "citation": "26 CFR § 1.174-1"},
{"docId": "doc_usf_guid_rr_2014_12", "contentType": "guidance", "citation": "Rev. Rul. 2014-12"}
],
"download": {
"pdf": {"url": "https://signed.supergood.ai/dl/abc123.pdf", "expiresAt": "2026-01-22T12:00:00Z"}
},
"clientMatter": null,
"updatedAt": "2026-01-20T13:45:00Z"
}
Smart Charts
POST /tax/smart-charts: Generate a multistate comparison for a given topic and jurisdictions.
curl --request POST \
--url https://api.supergood.ai/integrations/<integration_id>/tax/smart-charts \
--header 'Authorization: Bearer <authToken>' \
--header 'Content-Type: application/json' \
--data '{
"topicKey": "sales_tax_economic_nexus_thresholds",
"jurisdictions": ["CA", "NY", "TX", "FL"],
"asOfDate": "2026-01-01",
"includeCitations": true,
"clientMatter": {"clientId": "cl_2180", "matterId": "mat_442"}
}'
Example response
{
"chartId": "sc_6f2a91",
"topicKey": "sales_tax_economic_nexus_thresholds",
"asOfDate": "2026-01-01",
"columns": ["jurisdiction", "threshold", "measurementPeriod", "notes", "citation"],
"rows": [
{"jurisdiction": "CA", "threshold": ">$500k sales", "measurementPeriod": "current or prior calendar year", "notes": "Remote seller threshold.", "citation": "Cal. Rev. & Tax. Code § [ref]"},
{"jurisdiction": "NY", "threshold": ">$500k and 100 transactions", "measurementPeriod": "immediately preceding four sales tax quarters", "notes": "Economic nexus standard.", "citation": "N.Y. Tax Law § [ref]"},
{"jurisdiction": "TX", "threshold": ">$500k sales", "measurementPeriod": "last 12 months", "notes": "Remote seller guidance.", "citation": "34 Tex. Admin. Code § [ref]"},
{"jurisdiction": "FL", "threshold": ">$100k sales", "measurementPeriod": "previous calendar year", "notes": "Remote seller provisions.", "citation": "Fla. Stat. § [ref]"}
],
"export": {
"csv": {"url": "https://signed.supergood.ai/dl/sc_6f2a91.csv", "expiresAt": "2026-01-22T12:00:00Z"}
},
"createdAt": "2026-01-21T10:03:11Z"
}
Alerts
POST /tax/alerts: Create an alert that streams new or changed content matching a search or tracks specific citations/documents.
curl --request POST \
--url https://api.supergood.ai/integrations/<integration_id>/tax/alerts \
--header 'Authorization: Bearer <authToken>' \
--header 'Content-Type: application/json' \
--data '{
"name": "Bonus Depreciation Monitor",
"search": {
"query": "bonus depreciation OR 168(k)",
"jurisdictions": ["US-FED"],
"contentTypes": ["statute", "regulation", "guidance", "news"]
},
"frequency": "realtime",
"delivery": {
"webhookUrl": "https://grc.yourco.com/webhooks/lexis-tax",
"secret": "whsec_8e3f..."
},
"clientMatter": {"clientId": "cl_2180", "matterId": "mat_442"}
}'
Example response
{
"alertId": "alrt_51af80",
"status": "active",
"createdAt": "2026-01-21T11:20:44Z",
"nextDeliveryEstimate": "2026-01-21T11:21:15Z"
}
Technical Specifications
- Authentication: Username/password with MFA (SMS, email, TOTP) and SSO/OAuth where enabled; supports service accounts or customer-managed credentials
- Response format: JSON with consistent schemas for documents, citator metadata, smart charts, and alerts
- Rate limits: Tuned for enterprise throughput while honoring entitlements, content access rules, and fair use
- Session management: Automatic reauth and cookie/session rotation with health checks and challenge handling
- Data freshness: Near real-time retrieval of new/updated documents, citator signals, and chart outputs
- Security: Encrypted transport, scoped tokens, and audit logging; respects Lexis+ Tax role-based permissions and licensing
- Webhooks: Optional asynchronous delivery for alerts and long-running chart builds
Performance Characteristics
- Latency: Sub-second responses for list/detail queries under normal load
- Throughput: Designed for high-volume document sync, alert streaming, and chart generation
- Reliability: Retry logic, backoff, and idempotency keys minimize duplicate actions
- Adaptation: Continuous monitoring for UI/network changes with rapid adapter updates
Getting Started
- Schedule Integration Assessment
Book a 30-minute session to confirm your content sets, licensing, and authentication model.
- Supergood Builds and Validates Your API
We deliver a hardened Lexis+ Tax adapter tailored to your workflows and entitlements.
- Deploy with Monitoring
Go live with continuous monitoring and automatic adjustments as Lexis+ Tax evolves.
Frequently Asked Questions
Q: Which Lexis+ Tax modules can this integration cover?
Supergood supports workflows across commonly used modules such as Federal Tax (code, regs, IRS guidance, cases), State & Local Tax (statutes, regs, administrative materials, cases), News & Analysis, Shepard’s/Citator, and Smart Charts—subject to your licensing and entitlements. We scope coverage during integration assessment.
Q: How are MFA and SSO handled for automation?
We support username/password + MFA (SMS, email, TOTP) and can operate behind SSO/OAuth when enabled. Sessions are refreshed automatically with secure challenge handling.
Q: Can you push alerts and content into our GRC or audit platform?
Yes. We can deliver alerts via webhooks and normalize document metadata and citations to align with your GRC schema (e.g., ServiceNow GRC, Workiva). We also support scheduled exports and near real-time streaming for change events.
Q: Do you support Shepard’s signals and citing references?
Yes. We surface normalized signal states and summary counts, with optional expanded citing reference lists. We also expose related document links for quick drill-down while respecting entitlements.
Q: How do you handle content caching and licensing restrictions?
We cache metadata to optimize performance and adhere to customer-specific licensing for full-text retrieval. Downloads use time-limited, signed URLs. Access is constrained to your entitled content.
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