a coherent stack where each layer complements the others

A legal AI tech stack is the combination of AI-powered tools a law firm uses across its core functions — research, drafting, practice management, e-discovery, and billing. It's not one tool; it's a layered system where each component handles a specific job, and together they cover the full spectrum of legal work.

The firms getting the most from AI aren't the ones with the fanciest single tool. They're the ones with a coherent stack where each layer complements the others. A $20/month Claude subscription paired with Clio and Westlaw can outperform a $1,200/month Harvey deployment if the workflow integration is better.

The Five Layers of a Legal AI Tech Stack

Every legal AI stack has five functional layers. Layer 1 — Research: tools that search, analyze, and synthesize legal authorities (CoCounsel, Westlaw AI, vLex Vincent, Lexis+ AI). Layer 2 — Drafting: tools that generate legal documents from prompts, templates, or instructions (Claude, Harvey, Spellbook, Microsoft Copilot). Layer 3 — Practice Management: tools that automate workflows, calendaring, intake, and matter management (Clio, Smokeball, PracticePanther, MyCase). Layer 4 — Discovery: tools that handle document review, predictive coding, and e-discovery workflows (Relativity, Everlaw, Reveal, DISCO). Layer 5 — Billing & Analytics: tools that track time, generate invoices, and analyze firm performance (LawPay, TimeSolv, Clio's billing module). Not every firm needs all five layers. A transactional practice might skip Layer 4 entirely. A solo personal injury attorney might combine Layers 3 and 5 into a single platform. The stack should match the practice.

Example Stack: Solo Practitioner ($100/month)

A solo attorney or small practice under 5 attorneys can build an effective AI stack for about $100/month per attorney. Research: Claude Pro ($20/month) for case analysis + free Westlaw Edge or Google Scholar for citation verification. Drafting: Claude Pro (same subscription — Claude handles both research analysis and drafting). Practice Management: Clio Manage ($39/month) for calendaring, intake, and matter management. Discovery: not needed for most solo practices; use Claude for document analysis on small sets. Billing: Clio's built-in billing ($0 additional). Total: ~$60-100/month. This stack won't match what a 500-attorney firm runs, but it covers 80% of AI needs. The key insight: Claude Pro is the best value in legal AI because it handles both research analysis and drafting in a single $20/month subscription.

Example Stack: Mid-Size Firm (20-50 Attorneys, $200-400/month)

Mid-size firms need more specialization and integration. Research: CoCounsel with Westlaw ($150-300/user/month bundled) — the Westlaw integration means research AI has access to verified legal databases. Drafting: Claude Team ($25/user/month) for briefs, memos, correspondence, and contract drafting. Practice Management: Clio Suite or Smokeball ($50-80/user/month) — enterprise features for multi-attorney workflows, conflict checks, and client portals. Discovery: Relativity or Everlaw ($varies by matter) — TAR 2.0 for litigation matters with significant document review. Billing: integrated with practice management platform. Total: ~$250-400/user/month. The critical decision at this tier is CoCounsel vs. Claude for research. If the firm already pays for Westlaw, CoCounsel is the natural extension. If budget is tight, Claude Pro with manual citation verification is 90% as effective at 10% of the cost.

Example Stack: Am Law 100 Firm ($1,000-2,000/month)

Enterprise firms operate at a different scale. Research: Harvey ($1,200+/user/month) with custom agents trained on firm precedents, PLUS CoCounsel for Westlaw-integrated research. Drafting: Harvey's drafting agents configured with firm style guides and template libraries. Practice Management: enterprise platforms (iManage, NetDocuments) with AI-enhanced document management. Discovery: Relativity with AI analytics, custom TAR workflows, and privilege detection models. Billing: enterprise billing systems (Aderant, Elite 3E) with AI-powered invoice review and rate analysis. Total: $1,500-2,500+/user/month. At this level, firms are also investing in AI operations teams — dedicated staff who manage AI tools, train custom models, build prompts libraries, and measure ROI. The budget for AI ops alone can run $500K-2M annually. The Am Law 100 advantage isn't better tools — it's better integration and customization of those tools.

How to Build Your Stack: The Decision Framework

Don't start with tools. Start with problems. Step 1: Identify the three tasks that consume the most attorney time at your firm. For most firms, it's research, drafting, and document management. Step 2: Map each task to a stack layer and evaluate tools within that layer based on your budget. Step 3: Check integrations — tools that connect to your existing systems (DMS, email, practice management) reduce friction. Tools that require manual data transfer create it. Step 4: Start with one layer. Most firms should start with Layer 2 (Drafting) because Claude Pro at $20/month delivers the fastest visible ROI with the lowest risk. Step 5: Add layers based on measured results. If drafting AI saved 5 hours/week, that justifies investing in research AI. Don't buy the full stack on day one. The firms that succeed with AI stack incrementally based on proven value at each layer.

The Bottom Line: A legal AI tech stack has five layers: research, drafting, practice management, discovery, and billing. Solo practitioners can build an effective stack for $100/month. Mid-size firms spend $200-400/user/month. Am Law 100 firms invest $1,500+/user/month. Start with drafting (Claude Pro, $20/month) — it delivers the fastest ROI with the lowest risk.