Files
ANGX 4e07a6a874 feat(stdlib)!: Agent Skills v1.0 conformance, resolver fix, and 17 new skills (#43)
* chore(stdlib): add conformance tooling for the skills library

The library had no gate that could express what a valid skill is, so
malformed frontmatter, over-budget files and credential literals went
unnoticed. These scripts define and enforce that contract.

- validate-skills.py: extend with Agent Skills v1.0 conformance -
  naming rules and directory agreement, an explicit activation trigger
  in the description, canonical layout, the 500-line SKILL.md budget,
  relative-link integrity, and two security rules (no unrestricted
  Bash(*) grant, no credential literals). Structural checks now read a
  skill as a whole so material moved into references/ still counts.
- split-skill-references.py: move the heaviest sections of an oversized
  SKILL.md into references/. Verifies line by line that every source
  line lands in exactly one output and refuses to write otherwise.
- generate-skill-inventory.py: derive SKILLS_INVENTORY.md and
  DIRECTORY_STRUCTURE.md from the tree so they cannot drift.
- generate-skill-catalog.py: index the canonical layout only, count
  references/ toward a skill's size, and stop truncating descriptions
  at 200 characters - the catalog is the discovery surface and must
  carry the activation trigger.
- .gitignore: Python bytecode from these scripts, and local .pcl state.

Reviewed-by: Security Analyst, Compiler Engineer, DevX Engineer

* fix(stdlib): bring all 174 skills to Agent Skills v1.0 conformance

No skill in the library was conformant. 41 of 175 failed the existing
validator outright, and none satisfied the spec. This pass fixes the
tree and records the result. See stdlib/CHANGELOG.md for the per-skill
versioning and migration notes.

BREAKING CHANGE: one skill removed, five moved, seven with a capability
withdrawn. Library version 2.0.0 -> 3.0.0.

Structure
- Convert 71 skills stored as flat files to <category>/<name>/SKILL.md,
  the layout the spec requires and the only one able to carry companion
  resources.
- Rename 5 directories that disagreed with their declared name:, so
  resolution by path and by name stop giving different answers. The
  repository docs already referenced the corrected paths.
- Merge the duplicate legal-technology skills into legaltech-expert and
  delete legal-tech-expert, carrying over everything the survivor
  lacked.

Metadata
- Repair 20 unparseable frontmatters: an H1 preceded the --- block and
  the key was skill_id: instead of name:, so any parser reading
  frontmatter at offset 0 saw no metadata at all. The objectives,
  prerequisites and outcome they carried become real body sections.
- Add the missing version: to 21 skills, fold keywords into tags, move
  expertise_level under metadata, and align 10 category: values with
  their directory.

Discoverability
- Give all 174 descriptions an explicit "Use when ..." trigger, built
  from each skill's own tags and section headings. 152 previously said
  only what the skill was about, leaving an agent nothing to match on.

Progressive disclosure
- Split 127 oversized skills, moving bulk material into references/ read
  on demand and leaving an index behind. A SKILL.md now averages 277
  lines instead of 644 and none exceeds 500. Verified lossless line by
  line against the previous revision.

Security
- Withdraw the unrestricted Bash(*) grant from 7 skills; none of the six
  non-financial ones contained a single shell command. finance-expert
  documents code that charges cards and reads bank accounts, so it now
  grants no shell at all.
- Remove credential literals: Stripe keys, two JWT signing keys, an
  Express session secret, a Redis password and WiFi credentials, all
  inlined in examples. They load from the environment now.
- finance-expert: idempotency keys were documented but absent, so a
  retry double-charged; webhook signature failures were not caught, so a
  forged event raised uncaught instead of being rejected;
  int(amount * 100) truncated fractions of a cent. All fixed, plus a
  money-movement guardrails section.
- trading-expert: place_order routed without any pre-trade risk check
  although a RiskManager sat unused in the next section. Risk validation
  now runs before routing and raises rather than returning a boolean a
  caller can ignore; live routing is opt-in.
- Correct an Ansible Vault example that showed plaintext under an
  "encrypted" label.

Also fixes 8 broken documentation links and a prematurely closed code
fence in skill-creator-expert that leaked template content into prose.

Per the repository file-organization policy, four stale progress reports
(SKILLS_MANIFEST, COMPLETE_SKILLS_LIBRARY, COMPLETE_LIBRARY_MANIFEST,
PHASE_3_DATA_ANALYTICS) move out of stdlib/ into the gitignored
.roadmap/status/stdlib/; they claimed 31 of 100 skills complete. They
appear here as deletions because .roadmap/ is not tracked.

Reviewed-by: Security Analyst, Language Designer, DevX Engineer,
             Documentation Specialist

* fix(skills): resolve standard library skills from their real layout

No stdlib skill was resolvable. SkillResolver looked for
`<stdlibDir>/<name>.md` with stdlibDir defaulting to `stdlib/skills`, a
directory that does not exist, and the path ignored the category level
the library actually uses. The two LSP providers had the same wrong
directory and scanned only one level deep, so neither completion nor
go-to-definition could see a skill either.

- skill-discovery.ts: enumerate skill entry points across the shapes in
  use - a flat `<name>.md`, `<name>/SKILL.md`, and
  `<category>/<name>/SKILL.md` - while skipping references/, scripts/
  and assets/, which hold supporting material rather than entry points.
- skill-resolver.ts: point stdlibDir at `stdlib`, and look the name up
  as a directory under any category as well as the two legacy shapes, so
  existing custom stdlib directories keep working. The name is used as a
  single path segment and rejected if it contains a separator or
  traversal, so a reference cannot escape the stdlib root.
- Rewire both LSP providers onto the shared discovery helper.

Tests: 13 new cases covering the layouts, ordering, the references/
exclusion, path-traversal rejection, and an integration test that
resolves real shipped skills by bare name.

Reviewed-by: Compiler Engineer, Runtime Architect, Security Analyst

* feat(stdlib): add 17 skills covering the library's largest gaps

Selection was driven by cross-referencing coverage against observed usage
rather than by intuition: Stack Overflow and GitHub Octoverse data for
which technologies matter, and install rankings on public agent-skill
registries for the shape of skills people actually use.

That comparison found a mismatch of form, not only of coverage. The
most-installed skills in the ecosystem are procedures - tdd, refactoring,
frontend design, browser automation - while all 174 existing skills were
domain knowledge shaped as <domain>-expert. The new workflows/ category
closes that gap and introduces the <activity>-workflow convention.

New category workflows/ (4)
- tdd-workflow, refactoring-workflow, debugging-workflow,
  code-review-workflow. code-review-workflow complements rather than
  replaces code-review-expert: procedure versus judgement. Merge them if
  the split proves confusing in use.

Applied AI (3) - the largest coverage gap
- llm-engineering-expert, rag-expert, agent-engineering-expert.
  The library referenced LLMs in tags but covered none of it: pgvector
  appeared zero times across 174 skills, LangChain once, MCP twice
  despite the repository shipping an MCP integration guide.

Capabilities (2)
- document-processing-expert (PDF, DOCX, XLSX, PPTX in one skill),
  browser-automation-expert (a client against third-party sites,
  distinct from playwright-expert which tests your own application).

Data (3)
- mysql-expert, the second most used database and previously absent
  while rarer stores had skills; analytical-databases-expert;
  stream-processing-expert.

Security (3)
- secrets-management-expert, supply-chain-security-expert (OWASP A03
  2025), identity-access-expert (OWASP A01).

Interface and meta (2)
- accessibility-expert: design/ held only design-expert, which despite
  its name covers software architecture, so WCAG had no home.
- skill-router: find and compose skills across 191, with a
  disambiguation table for overlapping pairs.

Grouping by decision context rather than by technology keeps the growth
to 17 skills for roughly 50 topics. Five vector stores live inside
rag-expert; four document formats inside document-processing-expert.
Per-tool depth sits in references/, which the progressive-disclosure work
in 3.0.0 made cheap.

Four further gaps are better served by extending existing skills -
PyTorch and TensorFlow in ml-expert, OpenTelemetry in monitoring-expert,
Pulumi and Crossplane in terraform-expert - and are not in this change.

Library 3.0.0 -> 3.1.0, additive only. Adds the workflows label to the
inventory generator; catalogue, inventory, structure and CHANGELOG
regenerated.

Reviewed-by: Product Strategist, Security Analyst, DevX Engineer,
             Documentation Specialist

* fix(test): create test directories with mkdtempSync

CodeQL flagged js/insecure-temporary-file (CWE-377) on both suites.
`join(tmpdir(), <predictable name>)` followed by mkdirSync creates a
world-readable directory at a guessable path, so another local user can
pre-create it or plant a symlink between the name being computed and the
directory being created.

mkdtempSync creates the directory atomically with a random suffix and
0700 permissions, which closes both the disclosure and the race.

One occurrence is new in this branch (skill-discovery); the other
pre-dates it in skill-resolver and is fixed in the same pass rather than
left as a known finding in a file this branch already touches.
2026-09-05 04:35:30 +02:00
..

PCL Standard Library (stdlib)

Version: 3.1.0 Status: ✅ Production Ready Total Skills: 191 Expert-Level Skills


🎯 What is the Standard Library?

The PCL Standard Library is a comprehensive collection of 191 expert-level skills for AI agent personas, providing deep domain expertise across programming languages, frameworks, cloud platforms, data systems, security, and industry verticals.

Each skill represents expert-level mastery in a specific domain with:

  • Core Concepts: Fundamental principles and architecture
  • Code Examples: Production-ready implementations (250-800+ lines)
  • Best Practices: Industry standards and proven patterns
  • Anti-Patterns: Common mistakes to avoid
  • Resources: Documentation, tools, and learning materials

📊 Library Statistics

  • Total Skills: 191 expert-level skills
  • Categories: 15 major domains
  • Total Content: ~114,000 lines of expert knowledge (48,000 in skill entry points, 66,000 in on-demand reference documents)
  • Coverage: Languages, Frameworks, Cloud, Data, Security, DevOps, Industries, and more

🗂️ Skill Categories

Category Count Examples
Domains 58 Healthcare, Finance, LegalTech, Manufacturing, Energy, AgTech, Web3
Workflows 4 TDD, refactoring, debugging, code review — procedures, not knowledge
Languages 23 Python, TypeScript, Rust, Go, Java, Kotlin, Scala, Haskell, Julia, Zig
DevOps 16 Kubernetes, Docker, Terraform, ArgoCD, Prometheus, Grafana, Istio
Frameworks 15 React, Vue, Angular, Next.js, Django, Spring Boot, Flutter, Tauri
Data & Analytics 17 Snowflake, Databricks, Airflow, dbt, Tableau, Power BI, Kafka
Security 12 Penetration Testing, Zero Trust, GDPR, SOC2, Cryptography
Tools 12 Git, Slack, Teams, Discord, WebRTC, Video Streaming, Code Review
QA & Testing 7 Playwright, Cypress, Jest, Selenium, Load Testing, Chaos Engineering
API & Integration 6 REST, GraphQL, gRPC, Microservices, API Design
Professional 5 Banking, Legal, Accounting, FinOps, Standards
AI & ML 7 Machine Learning, AI Architecture, Data Science
Cloud Platforms 4 AWS, Azure, GCP, Cloudflare
Scientific 3 Quantum Computing, Bioinformatics, Research
Design 2 System & UX Design

See SKILLS_INVENTORY.md for the complete skill list.

🚀 Quick Start

1. Browse Available Skills

# List all skills
find stdlib -name SKILL.md

# Search for a specific domain
find stdlib -type d -name "*react*"
find stdlib -type d -name "*kubernetes*"

# Machine-readable index
cat stdlib/catalog/skill-index.json

2. Load Skills into a Persona

# persona.pcl
persona "FullStackDeveloper" {
  version = "1.0.0"

  # Load skills from stdlib
  skills = [
    "stdlib/languages/typescript-expert",
    "stdlib/frameworks/react-expert",
    "stdlib/frameworks/nextjs-expert",
    "stdlib/data/postgresql-expert",
    "stdlib/devops/docker-expert"
  ]

  constraints {
    max_tokens = 8000
    allowed_tools = ["Read", "Write", "Edit", "Bash"]
  }
}

3. Use Skills in Multi-Agent Systems

# multi-agent-system.pcl
system "DataPlatform" {

agent "DataEngineer" {
skills = [
"stdlib/data/airflow-expert",
"stdlib/data/dbt-expert",
"stdlib/data/snowflake-expert",
"stdlib/languages/python-expert"
]
role = "Build and maintain data pipelines"
}

agent "DataAnalyst" {
skills = [
"stdlib/data/tableau-expert",
"stdlib/data/powerbi-expert",
"stdlib/data/sql-expert"
]
role = "Create dashboards and analytics"
}

agent "MLEngineer" {
skills = [
"stdlib/ai/ml-expert",
"stdlib/data/databricks-expert",
"stdlib/languages/python-expert"
]
role = "Train and deploy ML models"
}
}

📖 Skill Format

Each skill follows the PCL Agent Skills Specification:

---
name: skill-name
version: 1.0.0
description: Brief description of the skill
category: domain
tags: [tag1, tag2, tag3]
allowed-tools:
  - Read
  - Write
  - Edit
  - Bash(command:*)
---

# Skill Title

Brief introduction to the skill domain.

## Core Concepts

### Concept 1

Explanation...

## Code Examples

\`\`\`language
// Production-ready code example
// 50-200 lines demonstrating real-world usage
\`\`\`

## Best Practices

- Practice 1
- Practice 2

## Anti-Patterns

❌ Anti-pattern 1
❌ Anti-pattern 2

## Resources

- Documentation: https://...
- Tools: https://...

🎭 Example Personas

Full-Stack Web Developer

persona "FullStackDev" {
  description = "Expert full-stack web developer"

  skills = [
    # Frontend
    "stdlib/languages/typescript-expert",
    "stdlib/frameworks/react-expert",
    "stdlib/frameworks/nextjs-expert",

    # Backend
    "stdlib/languages/nodejs-expert",
    "stdlib/frameworks/fastapi-expert",
    "stdlib/api/graphql-expert",

    # Database
    "stdlib/data/postgresql-expert",
    "stdlib/data/redis-expert",

    # DevOps
    "stdlib/devops/docker-expert",
    "stdlib/devops/kubernetes-expert",
    "stdlib/cloud/aws-expert"
  ]

  constraints {
    governance_level = "high"
    risk_classification = "medium"
  }
}

Cloud Security Architect

persona "SecurityArchitect" {
  description = "Expert in cloud security and compliance"

  skills = [
    # Security
    "stdlib/security/zero-trust-expert",
    "stdlib/security/cryptography-expert",
    "stdlib/security/penetration-testing-expert",

    # Compliance
    "stdlib/security/gdpr-expert",
    "stdlib/security/soc2-expert",

    # Cloud
    "stdlib/cloud/aws-expert",
    "stdlib/cloud/azure-expert",
    "stdlib/devops/kubernetes-expert",
    "stdlib/devops/istio-expert"
  ]

  constraints {
    governance_level = "critical"
    risk_classification = "high"
    audit_required = true
  }
}

Data Platform Engineer

persona "DataEngineer" {
  description = "Expert in modern data platforms"

  skills = [
    # Languages
    "stdlib/languages/python-expert",
    "stdlib/languages/scala-expert",

    # Data Platforms
    "stdlib/data/snowflake-expert",
    "stdlib/data/databricks-expert",

    # Orchestration
    "stdlib/data/airflow-expert",
    "stdlib/data/dbt-expert",

    # Streaming
    "stdlib/data/kafka-expert",

    # Cloud
    "stdlib/cloud/aws-expert",
    "stdlib/devops/terraform-expert"
  ]

  constraints {
    governance_level = "high"
    data_classification = ["pii", "confidential"]
  }
}

🔍 Skill Discovery

By Technology Stack

MERN Stack:

  • mongodb-expert
  • nodejs-expert
  • react-expert
  • typescript-expert

Data Science Stack:

  • python-expert
  • data-science-expert
  • ml-expert
  • databricks-expert

Cloud Native Stack:

  • kubernetes-expert
  • istio-expert
  • prometheus-expert
  • grafana-expert
  • argocd-expert

Mobile Development:

  • flutter-expert
  • react-native-expert
  • ios-expert
  • android-expert

By Industry

Healthcare: healthcare, healthtech-expert, pharmaceutical-expert Finance: banking-expert, fintech-expert, trading-expert Legal: lawyer-expert, legal-tech, legaltech-expert Manufacturing: manufacturing-expert, iot-expert Agriculture: farming, agtech-expert

🛡️ Governance & Security

Skills integrate with PCL's governance framework:

Risk Classification

skill "penetration-testing-expert" {
  risk_level = "high"          # Can execute security tests
  requires_approval = true      # Human approval needed
  audit_all_actions = true      # Log everything
}

skill "react-expert" {
  risk_level = "low"           # UI development only
  requires_approval = false
}

Tool Permissions

# Skill declares what tools it needs
allowed-tools:
  - Read # Can read files
  - Write # Can write files
  - Edit # Can edit files
  - Bash(npm:*, yarn:*) # Can run npm/yarn only
  - Bash(kubectl:get:*) # Can only run kubectl get

Compliance Alignment

Skills support compliance frameworks:

  • ISO 42001 - AI risk management
  • ISO 27001 - Information security
  • GDPR - Data protection (gdpr-expert skill)
  • SOC 2 - Security controls (soc2-expert skill)
  • OWASP - Security best practices

📚 Skill Composition Patterns

Layered Architecture

persona "EnterpriseBackend" {
  skills = [
    # Layer 1: Language
    "stdlib/languages/java-expert",

    # Layer 2: Framework
    "stdlib/frameworks/spring-boot-expert",

    # Layer 3: Data
    "stdlib/data/postgresql-expert",
    "stdlib/data/redis-expert",

    # Layer 4: Integration
    "stdlib/api/microservices-expert",
    "stdlib/api/graphql-expert",

    # Layer 5: Infrastructure
    "stdlib/devops/kubernetes-expert",
    "stdlib/devops/istio-expert",
    "stdlib/cloud/aws-expert"
  ]
}

Cross-Functional Teams

system "ProductDevelopment" {

persona "Frontend" {
skills = ["react-expert", "typescript-expert", "cypress-expert"]
}

persona "Backend" {
skills = ["go-expert", "postgresql-expert", "microservices-expert"]
}

persona "DevOps" {
skills = ["kubernetes-expert", "terraform-expert", "prometheus-expert"]
}

persona "Security" {
skills = ["penetration-testing-expert", "zero-trust-expert"]
}
}

📊 Documentation

Both documents are generated; rerun python scripts/generate-skill-inventory.py after changing the tree rather than editing them.

🔧 Development & Contributing

Creating Custom Skills

  1. Copy an existing skill as template:
cp -r stdlib/languages/python-expert stdlib/languages/my-skill
  1. Edit SKILL.md with your expertise

  2. Validate the skill:

python scripts/validate-skills.py

Maintenance commands

python scripts/validate-skills.py           # conformance gate (must pass)
python scripts/split-skill-references.py    # keep SKILL.md under 500 lines
python scripts/generate-skill-catalog.py    # rebuild catalog/
python scripts/generate-skill-inventory.py  # rebuild inventory + structure docs

See CONTRIBUTING.md for contribution guidelines.

📈 What's New in v3.1.0

17 new skills, taking the library from 174 to 191 and adding a fifteenth category. Chosen by cross-referencing coverage gaps against observed usage — developer survey data and the install rankings of public agent-skill registries.

  • workflows/ (new category, 4 skills) — tdd-workflow, refactoring-workflow, debugging-workflow, code-review-workflow. Procedures rather than knowledge: the shape that dominates real agent-skill usage and that the library had none of.
  • Applied AI (3) — llm-engineering-expert, rag-expert, agent-engineering-expert. The largest coverage gap: the library mentioned LLMs in tags but had no skill on prompting, retrieval or tool use.
  • Capabilities (2) — document-processing-expert (PDF, DOCX, XLSX, PPTX in one skill), browser-automation-expert (distinct from playwright-expert, which is for testing your own application).
  • Data (3) — mysql-expert (the second most used database, previously absent), analytical-databases-expert, stream-processing-expert.
  • Security (3) — secrets-management-expert, supply-chain-security-expert (OWASP A03 2025), identity-access-expert (OWASP A01).
  • Interface (1) — accessibility-expert. The design/ category held only software architecture; WCAG conformance had no home.
  • Meta (1) — skill-router, for finding and composing skills across 191.

Grouping was deliberate: five vector stores live inside rag-expert, four document formats inside document-processing-expert. Roughly fifty topics are covered by seventeen skills, with per-tool detail in references/.

📈 What's New in v3.0.0

Agent Skills v1.0 conformance. Every skill now passes scripts/validate-skills.py. This release has breaking changes — one skill removed, five moved, seven with capabilities withdrawn. See CHANGELOG.md for the migration notes.

  • Uniform layout — all 174 skills live at stdlib/<category>/<name>/SKILL.md; 71 flat files were converted, and 5 directories renamed to match their declared name:.
  • Repaired metadata — 20 skills had an unparseable frontmatter block (an H1 preceded it, and the key was skill_id: instead of name:), so tooling saw no metadata at all; 21 more were missing version:.
  • Discoverable descriptions — every description states an explicit Use when ... trigger naming the keywords and tasks that select the skill.
  • Progressive disclosure — 127 oversized skills were split, moving bulk material into references/ read on demand. A SKILL.md now averages 277 lines instead of 644, so activating a skill costs a fraction of the context it did.
  • Deduplicated — the two overlapping legal-technology skills were merged into legaltech-expert.

📈 What's New in v2.0.0

Major Expansion: 100 → 173 skills (+73 skills)

New Categories Added:

  • Modern Languages: Zig, Nim, Julia, Haskell, Clojure
  • Modern Frameworks: Vue, Angular, Svelte, Next.js, Remix, Flutter, Tauri
  • Emerging Tech: Web3, Metaverse, Edge Computing, Serverless, WebAssembly, Robotics, 5G
  • Data Platforms: Snowflake, Databricks, Airflow, dbt, Looker, Tableau, Power BI
  • Security & Compliance: Penetration Testing, Zero Trust, GDPR, SOC2, Cryptography
  • Cloud Native: Istio, Helm, ArgoCD, Prometheus, Grafana, Linkerd
  • Mobile & Desktop: Flutter, React Native, iOS, Android, Electron, Tauri
  • Industry Specializations: Pharmaceutical, Biotech, FinTech, RegTech, PropTech, CleanTech
  • Enterprise Systems: SAP, Salesforce, ServiceNow, Workday, Oracle, Microsoft 365
  • Testing & QA: Playwright, Cypress, Jest, Selenium, Load Testing, Chaos Engineering
  • Communication: Slack, Teams, Discord, WebRTC, Video Streaming

📝 License

Part of the PCL project. See LICENSE for details.


The PCL Standard Library - Governed AI expertise at scale 🚀

Last Updated: 2026-01-19 Maintainer: PCL Team Status: ✅ Production Ready