How do I install the Common skill?

Run npx skillmds@latest add fdu-ins/common in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is Common safe to use?

This skill has not completed SkillMD's automated safety review yet. Independent scanners report: SkillSpector: PASS, Skill Scanner: PASS. Capability flags: reads secrets. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Common?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Common free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published Common?

FDU-INS (@fdu-ins) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Common by fdu-ins — Agent Skill

Name: Common
Rating: 4.2 (5 reviews)
Author: FDU-INS

Common

Cross-product infrastructure for HealthSim — persistence (cohort save/load), identity correlation (SSN-based cross-product linking), and DuckDB database operations. Use when saving/loading cohorts, linking entities across products, or querying the database directly.

FDU-INS Updated Sep 10, 2026

File contents

Common Skills - Master Reference

Cross-product infrastructure skills that enable persistence, identity correlation, and database operations across all HealthSim products.

Quick Start

# Save your current work
Save this cohort as "demo-patients"

# Load previous work
Load the cohort named "demo-patients"

# Find related entities
Find the member record for patient MRN-12345

# Query the database
Show me all cohorts created in the last week

Core Capabilities

State Management

Persist generated data across sessions with cohort save/load operations. Supports auto-persist for token-efficient batch generation.

Triggers: save, load, persist, resume, snapshot, restore Details: state-management.md

Identity Correlation

Link entities across products using SSN as the universal correlator. Track the same person as patient, member, rx member, and trial subject.

Triggers: find member, link patient, correlate, same person, cross-reference Details: identity-correlation.md

DuckDB Operations

Direct database access for advanced queries, schema exploration, and reference data access.

Triggers: query, SQL, schema, database, show tables Details: duckdb-skill.md

Cross-Product Architecture

Common skills enable data flow between products:

┌─────────────┐    ┌─────────────┐    ┌─────────────┐
│  PatientSim │    │  MemberSim  │    │ RxMemberSim │
│   (MRN)     │    │   (MBI)     │    │  (RxID)     │
└──────┬──────┘    └──────┬──────┘    └──────┬──────┘
       │                  │                  │
       └────────┬─────────┴─────────┬────────┘
                │                   │
         ┌──────▼───────┐   ┌───────▼──────┐
         │  Identity    │   │    State     │
         │ Correlation  │   │  Management  │
         │   (SSN)      │   │  (Cohorts)   │
         └──────────────┘   └──────────────┘
                │                   │
                └─────────┬─────────┘
                          │
                   ┌──────▼──────┐
                   │   DuckDB    │
                   │  Database   │
                   └─────────────┘

Database Schema

Common skills work with these core tables:

Table	Purpose	Key Columns
cohorts	Saved cohort metadata	cohort_id, name, created_at
persons	Core person identity	person_id, ssn, demographics
patients	PatientSim entities	patient_id, mrn, person_id
members	MemberSim entities	member_id, mbi, person_id
rx_members	RxMemberSim entities	rx_member_id, rx_id, person_id

Related Skills

Generation Skills - Profile and journey building
PopulationSim - Reference data and population targeting
NetworkSim - Provider network modeling

Part of HealthSim Workspace Infrastructure

---name: commondescription: Cross-product infrastructure for HealthSim — persistence (cohort save/load), identity correlation (SSN-based cross-product linking), and DuckDB database operations. Use when saving/loading cohorts, linking entities across products, or querying the database directly.---# Common Skills - Master ReferenceCross-product infrastructure skills that enable persistence, identity correlation, and database operations across all HealthSim products.## Quick Start```# Save your current workSave this cohort as "demo-patients"# Load previous workLoad the cohort named "demo-patients"# Find related entitiesFind the member record for patient MRN-12345# Query the databaseShow me all cohorts created in the last week```## Core Capabilities### State ManagementPersist generated data across sessions with cohort save/load operations. Supports auto-persist for token-efficient batch generation.**Triggers**: save, load, persist, resume, snapshot, restore**Details**: [state-management.md](state-management.md)### Identity CorrelationLink entities across products using SSN as the universal correlator. Track the same person as patient, member, rx member, and trial subject.**Triggers**: find member, link patient, correlate, same person, cross-reference**Details**: [identity-correlation.md](identity-correlation.md)### DuckDB OperationsDirect database access for advanced queries, schema exploration, and reference data access.**Triggers**: query, SQL, schema, database, show tables**Details**: [duckdb-skill.md](duckdb-skill.md)## Cross-Product ArchitectureCommon skills enable data flow between products:```┌─────────────┐ ┌─────────────┐ ┌─────────────┐│ PatientSim │ │ MemberSim │ │ RxMemberSim ││ (MRN) │ │ (MBI) │ │ (RxID) │└──────┬──────┘ └──────┬──────┘ └──────┬──────┘ │ │ │ └────────┬─────────┴─────────┬────────┘ │ │ ┌──────▼───────┐ ┌───────▼──────┐ │ Identity │ │ State │ │ Correlation │ │ Management │ │ (SSN) │ │ (Cohorts) │ └──────────────┘ └──────────────┘ │ │ └─────────┬─────────┘ │ ┌──────▼──────┐ │ DuckDB │ │ Database │ └─────────────┘```## Database SchemaCommon skills work with these core tables:| Table | Purpose | Key Columns ||-------|---------|-------------|| cohorts | Saved cohort metadata | cohort_id, name, created_at || persons | Core person identity | person_id, ssn, demographics || patients | PatientSim entities | patient_id, mrn, person_id || members | MemberSim entities | member_id, mbi, person_id || rx_members | RxMemberSim entities | rx_member_id, rx_id, person_id |## Related Skills- [Generation Skills](../generation/SKILL.md) - Profile and journey building- [PopulationSim](../populationsim/SKILL.md) - Reference data and population targeting- [NetworkSim](../networksim/SKILL.md) - Provider network modeling---*Part of HealthSim Workspace Infrastructure*

Frequently asked questions