SimpleLegal

SimpleLegal is Onit's mid-market enterprise legal management (ELM) platform trusted by 550+ corporate legal departments. It provides matter management, eBilling, spend management, vendor management, legal requests, and legal operations analytics for in-house legal teams. The SimpleLegal API is organized around REST with predictable, resource-oriented URLs, enabling integration with ERP and finance systems to eliminate duplicate data entry and automate legal operations workflows.

Website: https://www.simplelegal.com/
API Documentation: https://developer.simplelegal.com/
Parent Company: https://www.onit.com/products/elm/simplelegal/
GitHub: https://github.com/SimpleLegal

API

SimpleLegal REST API

The SimpleLegal API is organized around REST with predictable, resource-oriented URLs. HTTP Basic authentication is used. All responses return JSON. The API supports PATCH for partial updates (POST also accepted). Pagination defaults to 25 items per page, configurable via page_size query parameter.

Base URL: https://app.simplelegal.com/api/v1
Authentication: HTTP Basic

Key Resources:

• /matters — Create, retrieve, and update legal matters
• /invoices — Submit and process legal invoices (eBilling)
• /vendors — Manage outside counsel and service providers
• /cost-codes — List billing and cost codes (UTBMS, GL codes)
• /users — Create and manage platform users
• /payments — Record invoice payments for AP/ERP sync

Key Capabilities:

• Create matters, invoices, vendors, users, and payments
• Retrieve lists of matters, invoices, cost codes, and more
• Update matter status, invoice approval, and vendor info
• Integrate with AP/ERP systems to eliminate duplicate data entry
• Track legal spend, budgets, and accruals per matter

Artifacts

OpenAPI

Spec	Description
simplelegal-openapi.yml	SimpleLegal REST API — matters, invoices, vendors, cost codes, users, payments

Rules

Ruleset	Description
simplelegal-rules.yml	Spectral ruleset enforcing SimpleLegal API conventions

Capabilities

Capability	Description
legal-operations-management.yaml	Unified legal operations management workflow — matters, invoices, vendors, spend, users

Shared Definitions:

Shared File	Description
shared/simplelegal.yaml	SimpleLegal API consumed definition

JSON Schema

Schema	Description
simplelegal-matter-schema.json	Legal matter schema
simplelegal-invoice-schema.json	Legal invoice schema
simplelegal-vendor-schema.json	Vendor schema

JSON Structure

Structure	Description
simplelegal-matter-structure.json	Matter field documentation
simplelegal-invoice-structure.json	Invoice field documentation

JSON-LD

Context	Description
simplelegal-context.jsonld	SimpleLegal legal operations vocabulary linked data context

Examples

Example	Description
simplelegal-create-matter-example.json	Create a new legal matter
simplelegal-list-invoices-example.json	List pending invoices for a matter
simplelegal-create-vendor-example.json	Create a new outside counsel vendor

Vocabulary

Vocabulary	Description
simplelegal-vocabulary.yml	SimpleLegal domain vocabulary covering matter management, eBilling, spend management, vendor relations, and legal operations

Common Properties

Property	URL
Website	https://www.simplelegal.com/
API Documentation	https://developer.simplelegal.com/
Blog	https://www.simplelegal.com/blog/
Parent Company	https://www.onit.com/products/elm/simplelegal/
GitHub	https://github.com/SimpleLegal
Support	https://support.simplelegal.com/
CounselGO Vendor Portal	https://www.simplelegal.com/counselgo
Legal Requests	https://info.simplelegal.com/legal-requests-datasheet

Tags

eBilling, Enterprise Legal Management, Legal Operations, Legal Spend Management, Matter Management, Vendor Management

Maintainers

• Kin Lane (kin@apievangelist.com)