Stop Hardcoding Pricing Tiers. Deploy a Dynamic Entitlement Engine.
The central source of truth for "what a user can do." Manage feature toggles, subscription plans, and real-time usage quotas via a high-performance Go microservice. Native REST, gRPC, and MCP server interfaces—your code checks limits, your AI agents check limits too.
The Anti-Pattern
In early-stage startups, feature logic is scattered everywhere. The frontend checks if a user is "Pro" to show a button, the backend checks the database to see if they can upload a file, and sales engineers manually edit database rows to grant custom limits. When pricing changes, the entire codebase breaks.
The Solution
The Launch Rail Entitlements service abstracts subscription logic away from your core product. Your domain services simply ask the engine, Can this tenant create another project? and the service calculates the answer in milliseconds based on their active plan, usage, and custom overrides.
Core Capabilities Out-of-the-Box
Everything required to manage complex B2B pricing models without spaghetti code.
Configuration as Code
Define your entire commercial catalog—from global features (FeatureDefinition) to subscription bundles (Plan)—using simple YAML files. Sync them directly to the database via API.
Real-Time Usage Tracking
High-concurrency tracking backed by PostgreSQL and Redis. Services can incrementally record usage (RecordUsage) or query if an action is allowed before executing it (CheckLimit).
Custom Enterprise Overrides
Close massive B2B deals without writing custom code. Use SubjectFeatureOverride to grant specific tenants temporary limits or custom feature access that supersedes their base plan.
Granular Aggregation
Natively track quotas across different time boundaries (e.g., maximum monthly API requests vs. total absolute storage gigabytes) using strict AggregationPeriod logic.
Under the Hood: Enterprise Architecture
This is not a lightweight wrapper; it is highly concurrent infrastructure built to sit in the critical path of your user requests.
Universal Connectivity
Powered by ConnectRPC, allowing internal services to perform high-speed gRPC checks, while external tools and dashboards can consume the exact same endpoints via standard HTTP/JSON.
Decoupled from Billing
This service assigns plans and resolves effective features (SubscriptionService), but it doesn't process credit cards. It is designed to sit cleanly downstream of Stripe, Paddle, or Moyasar.
Idempotent & Event-Driven
Built for distributed systems. Usage records accept an idempotency_key to guarantee accuracy in retries, and the service naturally emits usage threshold events to NATS or SQS.
AI Agents Talk to Entitlements Natively
Every Launch Rail service ships with a built-in MCP server. Your AI agents can discover tools, read resources, and execute actions—no wrappers, no custom integrations.
MCP Tools
Actions agents can execute
check_limitVerify if a tenant can perform an action based on their plan and usage
record_usageIncrement usage counters with idempotency key protection
assign_planSubscribe a tenant to a plan with optional trial period
override_featureGrant custom feature limits to a specific tenant
MCP Resources
Data agents can read
entitlements://tenants/{id}/featuresAll effective features and limits for a tenant including overrides
entitlements://plansFull plan catalog with feature definitions and tiers
entitlements://tenants/{id}/usageCurrent usage counters across all metered features
In Practice
What this looks like
“Can tenant Acme Corp create another project? They seem to be hitting their limit.”
Calls check_limit tool for 'max_projects' feature → tenant is on Pro plan (limit: 50) → current usage: 49 → responds: 'Yes, 1 remaining. Consider suggesting an upgrade to Enterprise (unlimited).'
Real-World Value: Entitlements in Action
See how teams across industries use Entitlements to ship faster, reduce costs, and deliver enterprise-grade experiences from day one.
Dynamic Feature Gating
Gate features like 'Advanced Analytics' or 'Custom Domains' by plan tier. Change what's included in Starter vs Pro by editing a YAML file—zero code deployment, instant pricing iteration.
Metered Usage & Quota Management
Track API calls, storage usage, or in-app actions in real-time. Soft limits trigger upgrade prompts, hard limits block actions instantly. Aggregation periods handle monthly vs absolute quotas.
Paywall & Content Access Control
Free users read 5 articles/month, Pro users get unlimited access, Enterprise gets API access. Usage tracking per content type with automatic period resets and custom enterprise overrides.
Seller Tier Management
Bronze sellers list 10 products, Gold sellers get priority placement and bulk uploads. Custom overrides let sales reps grant temporary premium access to close enterprise deals.
Why Buy the License? (The ROI)
Building an entitlement engine that correctly handles soft limits, hard limits, trial expirations, and custom enterprise overrides takes a dedicated billing infrastructure team.
With Launch Rail, you get the complete, production-ready Go source code today.
Own Your Data
Keep your pricing and usage data inside your own VPC, directly querying it for analytics without hitting third-party API limits.
Iterate Pricing Instantly
Change what features belong to the 'Starter' or 'Pro' plan by updating a single YAML file—zero code deployment required.