Creates JSON Schema validation files for skills, agents, hooks, workflows, and data structures. Ensures type safety and input validation across the framework.
Creates JSON Schema validation files for skills, agents, hooks, workflows, and data structures. Ensures type safety and input validation across the framework.
version
2.3.0
model
sonnet
invoked_by
both
user_invocable
true
tools
["Read","Write","Edit","Bash","Glob","Grep"]
best_practices
["Use JSON Schema draft-07 or later","Include descriptions for all properties","Define required vs optional clearly","Add examples in schema","Use $ref for reusable definitions","Validate schemas before saving"]
error_handling
graceful
streaming
supported
output_location
.claude/schemas/
verified
true
lastVerifiedAt
2026-02-28
dependencies
["research-synthesis"]
source
builtin
trust_score
100
provenance_sha
03770a6e40541670
Schema Creator Skill
WARNING: DO NOT WRITE DIRECTLY TO .claude/schemas/
Schema files are protected by unified-creator-guard.cjs (Gate 4 in CLAUDE.md).
Direct writes bypass post-creation steps (catalog updates, consumer assignment, integration verification).
Always use the schema-creator skill workflow for creating schemas.
Direct writes create "invisible artifacts" that no validator or agent can discover.
Creates JSON Schema validation files for the Claude Code Enterprise Framework. Schemas enforce type safety, input validation, and structural consistency across skills, agents, hooks, workflows, and custom data structures.
SYSTEM IMPACT ANALYSIS (CRITICAL - DO NOT SKIP)
After creating ANY schema, you MUST:
Register in appropriate location (global vs skill-local)
Update related validators to use the new schema
Add schema reference to CLAUDE.md if globally significant
Verification:
# Verify schema is valid JSON
node -e "JSON.parse(require('fs').readFileSync('.claude/schemas/<schema-name>.json'))"# Check schema existsls .claude/schemas/<schema-name>.json || ls .claude/skills/<skill>/schemas/<schema-name>.json
WHY: Invalid schemas cause silent validation failures. Unregistered schemas are never used.
Purpose
Schemas provide structured validation for:
Skill Inputs/Outputs - Validate data passed to and from skills
Agent Definitions - Validate agent YAML frontmatter and structure
Hook Definitions - Validate hook configuration and registration
Workflow Definitions - Validate workflow steps and configuration
Custom Data Structures - Validate project-specific data formats
Schema Types
Type
Location
Purpose
Skill Input
.claude/skills/{name}/schemas/input.schema.json
Validate skill invocation inputs
Skill Output
.claude/skills/{name}/schemas/output.schema.json
Validate skill execution outputs
Agent Definition
.claude/schemas/agent-definition.schema.json
Validate agent YAML frontmatter
Skill Definition
.claude/schemas/skill-definition.schema.json
Validate skill YAML frontmatter
Hook Definition
.claude/schemas/hook-definition.schema.json
Validate hook configuration
Workflow Definition
.claude/schemas/workflow-definition.schema.json
Validate workflow structure
Custom
.claude/schemas/{name}.schema.json
Project-specific validation
Reference Schema
Use .claude/schemas/agent-definition.schema.json as the canonical reference schema.
Before finalizing any schema, compare against reference:
Follows JSON Schema draft-07 or later (draft-2020-12 preferred)
Has $schema, $id, title, description, type fields
Required fields are documented in "required" array
REGISTRY_MATCH: Warn user — artifact is registered but file may be missing. Investigate before creating. Ask user to confirm.
SIMILAR_FOUND: Display candidates with scores. Ask user: "Similar artifact(s) exist. Continue with new creation or update existing?"
NO_MATCH: Proceed to next step.
Override: If user explicitly passes --force, skip this check entirely.
Step 1.5: Companion Check
Before proceeding with creation, run the ecosystem companion check:
Use companion-check.cjs from .claude/lib/creators/companion-check.cjs
Call checkCompanions("schema", "{schema-name}") to identify companion artifacts
Review the companion checklist — note which required/recommended companions are missing
Plan to create or verify missing companions after this artifact is complete
Include companion findings in post-creation integration notes
This step is informational (does not block creation) but ensures the full artifact ecosystem is considered.
Step 2: Gather Schema Requirements
Before creating a schema, understand:
1. WHAT data structure are you validating?
- Skill input/output
- Agent/skill/hook/workflow definition
- Custom data format
2. WHERE should the schema live?
- Global: .claude/schemas/ (framework-wide)
- Local: .claude/skills/{skill}/schemas/ (skill-specific)
3. WHAT are the required vs optional fields?
- Required: Must be present for valid data
- Optional: Enhance but not required
4. WHAT are the validation rules?
- Types (string, number, boolean, object, array)
- Patterns (regex for strings)
- Ranges (min/max for numbers)
- Enums (allowed values)
- Lengths (min/max for strings/arrays)
Step 3: Determine Schema Type and Location
Creating For
Schema Location
Example
New skill inputs
.claude/skills/{skill}/schemas/input.schema.json
tdd skill parameters
New skill outputs
.claude/skills/{skill}/schemas/output.schema.json
tdd skill results
Global definition
.claude/schemas/{name}.schema.json
test-results.schema.json
Reusable component
.claude/schemas/components/{name}.schema.json
task-status.schema.json
Step 4: Analyze Data Structure
Examine existing data or specify expected structure:
{"$schema":"https://json-schema.org/draft-07/schema#","$id":"https://claude.ai/schemas/{schema-name}","title":"{Schema Title}","description":"{What this schema validates}","type":"object","required":["field1","field2"],"properties":{"field1":{"type":"string","description":"Description of field1","minLength":1,"maxLength":100},"field2":{"type":"number","description":"Description of field2","minimum":0,"maximum":100},"optionalField":{"type":"boolean","description":"Optional boolean field","default":false}},"additionalProperties":false}
Step 6: Add Descriptions and Examples
Every property MUST have a description:
{"properties":{"name":{"type":"string","description":"The unique identifier for the resource in lowercase-with-hyphens format","pattern":"^[a-z][a-z0-9-]*$","examples":["my-skill","test-generator","code-reviewer"]}}}
Add top-level examples:
{"examples":[{"name":"example-skill","description":"An example skill for demonstration","version":"1.0.0"}]}
This step is CRITICAL. After creating the schema artifact, you MUST register it in the schema discovery system.
Phase 1 Context: Phase 1 is responsible for discovering and cataloging schemas for validation. Schemas created without registration are invisible to validators and other systems that need them for data validation.
After schema file is written and validated:
Create/Update Schema Registry Entry in appropriate location:
If registry doesn't exist, create .claude/context/artifacts/schema-catalog.md:
{"schemas":[{"name":"{schema-name}","id":"{schema-name}","$id":"https://claude.ai/schemas/{schema-name}","type":"{input|output|definition|global|component}","description":"{What this schema validates}","version":"1.0.0","filePath":".claude/schemas/{schema-name}.schema.json","validatesFor":["{artifact-type-1}","{artifact-type-2}"],"relatedSchemas":[],"usedBy":["{validator-hook}","{creator-skill}"]}]}
Register with Validators:
Update any validation hooks that should use this schema:
Check .claude/hooks/validation/ for relevant validators
Add schema to schemaMap in validators that need it
Phase 1 Integration: Schema registry is the discovery mechanism for Phase 1, enabling validators to find and apply schemas consistently across the system.
Step 9: System Impact Analysis (MANDATORY)
Before marking schema creation complete, verify ALL items:
[ ] Schema file created in correct location
[ ] Schema is valid JSON (parseable)
[ ] Schema has $schema, $id, title, description
[ ] All required fields defined in "required" array
[ ] All properties have descriptions
[ ] Examples included for complex schemas
[ ] Schema registry entry created (Step 7)
[ ] Validators registered with schema (if applicable)
[ ] SCHEMA_CATALOG.md updated (Step 7)
[ ] Related documentation updated
BLOCKING: If any item fails, schema creation is INCOMPLETE. All items must pass.
System Impact Analysis (MANDATORY)
After creating a schema, complete ALL of the following:
1. CLAUDE.md Update
Add to appropriate section if schema enables new capability
Section 3 for agent-related schemas
Section 4.1 for creator ecosystem schemas
Section 8.5 for skill-related schemas
2. Validator Integration
Check if hooks should validate against new schema
Update .claude/hooks/ if schema affects validation
Add to schemaMap in relevant validators
3. Related Schemas
Update related schemas if needed ($ref links)
Check for circular dependencies
Ensure $id values are unique
4. Documentation
Update .claude/docs/ if schema documents new pattern
Add schema to Existing Schemas Reference table
Update skill-catalog.md if schema is for a new skill
Verification Checklist:
# Check CLAUDE.md registration
grep "{schema-name}" .claude/CLAUDE.md
# Check for $ref usage in other schemas
grep -r "{schema-name}" .claude/schemas/
# Verify no duplicate $id
grep -h "\$id" .claude/schemas/*.json | sort | uniq -d
BLOCKING: Schema creation is NOT complete until all impact analysis items are verified.
Schema Templates
Basic Input Schema
{"$schema":"https://json-schema.org/draft-07/schema#","$id":"https://claude.ai/schemas/skill-name-input","title":"Skill Name Input Schema","description":"Input validation schema for skill-name skill","type":"object","required":[],"properties":{"target":{"type":"string","description":"Target file or directory path"},"options":{"type":"object","description":"Optional configuration","properties":{"verbose":{"type":"boolean","default":false}}}},"additionalProperties":false}
Basic Output Schema
{"$schema":"https://json-schema.org/draft-07/schema#","$id":"https://claude.ai/schemas/skill-name-output","title":"Skill Name Output Schema","description":"Output validation schema for skill-name skill","type":"object","required":["success"],"properties":{"success":{"type":"boolean","description":"Whether the skill executed successfully"},"result":{"type":"object","description":"The skill execution result","additionalProperties":true},"error":{"type":"string","description":"Error message if execution failed"}},"additionalProperties":false}
Definition Schema (for agents, skills, hooks)
{"$schema":"https://json-schema.org/draft-07/schema#","$id":"https://claude.ai/schemas/entity-definition","title":"Entity Definition Schema","description":"Schema for validating entity definition files","type":"object","required":["name","description"],"properties":{"name":{"type":"string","pattern":"^[a-z][a-z0-9-]*$","description":"Entity name in lowercase-with-hyphens format"},"description":{"type":"string","minLength":20,"maxLength":500,"description":"Clear description of the entity purpose"},"version":{"type":"string","pattern":"^\\d+\\.\\d+(\\.\\d+)?$","default":"1.0.0","description":"Semantic version number"}},"additionalProperties":true,"examples":[{"name":"my-entity","description":"A sample entity for demonstration purposes","version":"1.0.0"}]}
{"tools":{"type":"array","items":{"type":"string"},"minItems":1,"uniqueItems":true,"description":"List of available tools"},"skills":{"type":"array","items":{"type":"string","pattern":"^[a-z][a-z0-9-]*$"},"description":"List of skill names"}}
{"$defs":{"namePattern":{"type":"string","pattern":"^[a-z][a-z0-9-]*$","description":"Lowercase with hyphens"},"toolsList":{"type":"array","items":{"type":"string"},"minItems":1}},"properties":{"name":{"$ref":"#/$defs/namePattern"},"tools":{"$ref":"#/$defs/toolsList"}}}
This skill is part of the Creator Ecosystem. Use companion creators for related artifacts:
Gap Discovered
Required Artifact
Creator to Invoke
When
Domain knowledge needs a reusable skill
skill
Skill({ skill: 'skill-creator' })
Gap is a full skill domain
Existing skill has incomplete coverage
skill update
Skill({ skill: 'skill-updater' })
Close skill exists but incomplete
Capability needs a dedicated agent
agent
Skill({ skill: 'agent-creator' })
Agent to own the capability
Existing agent needs capability update
agent update
Skill({ skill: 'agent-updater' })
Close agent exists but incomplete
Domain needs code/project scaffolding
template
Skill({ skill: 'template-creator' })
Reusable code patterns needed
Behavior needs pre/post execution guards
hook
Skill({ skill: 'hook-creator' })
Enforcement behavior required
Process needs multi-phase orchestration
workflow
Skill({ skill: 'workflow-creator' })
Multi-step coordination needed
Artifact needs structured I/O validation
schema
Skill({ skill: 'schema-creator' })
JSON schema for artifact I/O
User interaction needs a slash command
command
Skill({ skill: 'command-creator' })
User-facing shortcut needed
Repeated logic needs a reusable CLI tool
tool
Skill({ skill: 'tool-creator' })
CLI utility needed
Narrow/single-artifact capability only
inline
Document within this artifact only
Too specific to generalize
Integration Chain
[SKILL-CREATOR] Creating new skill with validation...
-> Calls schema-creator for input/output schemas
-> Schemas created in .claude/skills/{skill}/schemas/
[AGENT-CREATOR] Creating agent with strict validation...
-> Agent uses agent-definition.schema.json for self-validation
-> Agent validates inputs using custom schemas
[WORKFLOW-CREATOR] Creating workflow with typed steps...
-> Each step output validates against schema
-> Workflow uses workflow-definition.schema.json
Existing Schemas Reference
Total Active Schemas: 27 (25 archived - see .claude/schemas/_archive/)
Actively Validated (Ajv): 8 schemas with runtime validation
Documentation Reference: 16 schemas as structural templates
Optional Validation: 3 schemas with paths defined but validation skipped
Note: All schemas located at .claude/schemas/ unless otherwise specified. See schema catalog for full details on consumers, validation methods, and integration status.
File Placement & Standards
Output Location Rules
This skill outputs to: .claude/schemas/
For skill-specific schemas: .claude/skills/<skill-name>/schemas/
Schema naming convention:
Global schemas: <name>.schema.json
Skill input: input.schema.json
Skill output: output.schema.json
Components: components/<name>.schema.json
Mandatory References
File Placement: See .claude/docs/FILE_PLACEMENT_RULES.md
Developer Workflow: See .claude/docs/DEVELOPER_WORKFLOW.md
Artifact Naming: See .claude/docs/ARTIFACT_NAMING.md
Workspace Conventions: See .claude/rules/workspace-conventions.md (output placement, naming, provenance)
Enforcement
File placement is enforced by file-placement-guard.cjs hook.
Invalid placements will be blocked in production mode.
Memory Protocol (MANDATORY)
Before starting:
cat .claude/context/memory/learnings.md
Check for:
Previously created schemas
Known validation issues
Schema naming conventions
After completing:
New schema created -> Append to .claude/context/memory/learnings.md
Validation issue found -> Append to .claude/context/memory/issues.md
Architecture decision -> Append to .claude/context/memory/decisions.md
ASSUME INTERRUPTION: Your context may reset. If it's not in memory, it didn't happen.
Iron Laws of Schema Creation
These rules are INVIOLABLE. Breaking them causes validation failures.
1. NO SCHEMA WITHOUT $schema FIELD
- Every schema MUST declare its JSON Schema version
- Use draft-07 or later: "$schema": "https://json-schema.org/draft-07/schema#"
2. NO SCHEMA WITHOUT title AND description
- Every schema MUST be self-documenting
- title: Short name of what it validates
- description: Detailed explanation of purpose
3. NO PROPERTY WITHOUT description
- Every property MUST have a description
- Readers should understand field purpose without external docs
4. NO REQUIRED FIELD WITHOUT DEFINITION
- If field is in "required" array, it MUST be in "properties"
- Undefined required fields cause silent validation failures
5. NO ADDITIONALPROPERTIES: true WITHOUT REASON
- Default to additionalProperties: false for strict validation
- Only allow additional properties when explicitly needed
6. NO SCHEMA WITHOUT VALIDATION TEST
- Test schema with valid AND invalid examples
- Schema that passes everything validates nothing
7. NO CREATION WITHOUT SYSTEM IMPACT ANALYSIS
- Check if related validators need updating
- Check if documentation needs updating
- Check if related schemas need cross-references
8. NO SCHEMA WITHOUT CLAUDE.MD REGISTRATION
- If schema enables new capabilities, update CLAUDE.md
- Section 4 (Self-Evolution) for agent/skill/workflow schemas
- Verify with: grep "schema-name" .claude/CLAUDE.md
9. IRON LAW II: TYPED TOOL CALLING (MODEL-AGNOSTIC INTERFACE)
- Every tool-facing schema MUST include "description" on every property
- This is Typed Tool Calling: the model resolves parameters from a typed
JSON Schema contract instead of inferring from free-form markdown prose
- Benefit: Reduces model hallucination by 40-60% vs. untyped instructions
- Every required field must have: "type", "description", and where applicable "enum"
- Use snake_case for property names for cross-framework compatibility
- For schemas consumed by AI agents, add a Google Dork to your research:
"$schema" "type": "object" "properties" filetype:json ("tool" OR "skill") [Domain]
- additionalProperties MUST be false unless explicitly justified
Validation Checklist (Run After Every Creation)
# Verify schema is valid JSON
node -e "JSON.parse(require('fs').readFileSync('.claude/schemas/{name}.schema.json'))"# Check required fields exist
node -e "const s = require('.claude/schemas/{name}.schema.json'); console.log('Has $schema:', !!s.\$schema); console.log('Has title:', !!s.title); console.log('Has description:', !!s.description);"# Check all required properties are defined
node -e "const s = require('.claude/schemas/{name}.schema.json'); const r = s.required || []; const p = Object.keys(s.properties || {}); console.log('Missing:', r.filter(x => !p.includes(x)));"# List all schemasls -la .claude/schemas/*.schema.json
Completion Checklist (all must be checked):
[ ] Schema file created with .schema.json extension
[ ] $schema field present (draft-07 or later)
[ ] title and description present
[ ] All properties have descriptions
[ ] required array matches defined properties
[ ] examples included for complex schemas
[ ] Schema validated with test data
[ ] System impact analysis completed
[ ] CLAUDE.md updated if schema enables new capabilities
[ ] Related schemas updated if needed ($ref links)
BLOCKING: If ANY item fails, schema creation is INCOMPLETE. All items must pass before proceeding.
Ecosystem Alignment Contract (MANDATORY)
This creator skill is part of a coordinated creator ecosystem. Any schema created here must align with related creators:
agent-creator for ownership and execution paths
skill-creator for capability packaging and assignment
hook-creator for enforcement and guardrails
workflow-creator for orchestration and phase gating
template-creator for standardized scaffolds
command-creator for user/operator command UX
tool-creator for executable automation surfaces
Cross-Creator Handshake (Required)
Before completion, verify all relevant handshakes:
Artifact route exists in .claude/CLAUDE.md and related routing docs.
Discovery/registry entries are updated (catalog/index/registry as applicable).
Companion artifacts are created or explicitly waived with reason.
validate-integration.cjs passes for the created artifact.
Skill index is regenerated when skill metadata changes.
Research Gate (Exa + arXiv — BOTH MANDATORY)
For new schema patterns, research is mandatory:
Use Exa for implementation and ecosystem patterns:
mcp__Exa__web_search_exa({ query: '<topic> JSON Schema 2025 best practices' })
Search arXiv for academic research (mandatory for AI/ML, agents, evaluation, orchestration, memory/RAG, security):
Via Exa: mcp__Exa__web_search_exa({ query: 'site:arxiv.org <topic> 2024 2025' })
Direct API: WebFetch({ url: 'https://arxiv.org/search/?query=<topic>&searchtype=all&start=0' })
Record decisions, constraints, and non-goals in artifact references/docs.
Keep schemas minimal and avoid over-specification.
arXiv is mandatory (not fallback) when topic involves: AI agents, LLM evaluation, orchestration, memory/RAG, security, or any emerging methodology.
Regression-Safe Delivery
Follow strict RED -> GREEN -> REFACTOR for behavior changes.
Run targeted tests for changed modules.
Run lint/format on changed files.
Keep commits scoped by concern (logic/docs/generated artifacts).
Post-Creation Integration
After creation completes, run the ecosystem integration checklist:
Call runIntegrationChecklist(artifactType, artifactPath) from .claude/lib/creators/creator-commons.cjs
Call queueCrossCreatorReview(artifactType, artifactPath) from .claude/lib/creators/creator-commons.cjs
Review the impact report — address all mustHave items before marking task complete
Log any shouldHave items as follow-up tasks
Integration verification:
Schema added to schema-catalog.md
Schema validator wired (if applicable)
Schema referenced by consuming artifacts
Schema has test data examples
Evaluation Note
Schema artifacts are deterministic and structurally verifiable — the Step 7 validation tests in this skill's workflow (AJV compilation, $id uniqueness check, required-field coverage, test-data round-trip) serve as the primary quality gate and provide stronger signal than LLM-as-judge scoring. For schemas that feed agent or hook output contracts, also validate against skill-evaluation-output.schema.json to ensure downstream evaluators can parse the results. Full evaluation protocol and grader/analyzer agent usage is documented in .claude/skills/skill-creator/EVAL_WORKFLOW.md.
