Template Renderer

Template Renderer

Step 1: Validate Inputs (SECURITY - MANDATORY)

Template Path Validation (SEC-SPEC-002):

• Verify template file exists within PROJECT_ROOT
• Reject any path traversal attempts (../)
• Only allow templates from .claude/templates/

Token Whitelist Validation (SEC-SPEC-003):

// Allowed tokens by template type
const SPEC_TOKENS = [
  'FEATURE_NAME',
  'VERSION',
  'AUTHOR',
  'DATE',
  'STATUS',
  'ACCEPTANCE_CRITERIA_1',
  'ACCEPTANCE_CRITERIA_2',
  'ACCEPTANCE_CRITERIA_3',
  'TERM_1',
  'TERM_2',
  'TERM_3',
  'HTTP_METHOD',
  'ENDPOINT_PATH',
  'PROJECT_NAME',
];

const PLAN_TOKENS = [
  'PLAN_TITLE',
  'DATE',
  'FRAMEWORK_VERSION',
  'STATUS',
  'EXECUTIVE_SUMMARY',
  'TOTAL_TASKS',
  'FEATURES_COUNT',
  'ESTIMATED_TIME',
  'STRATEGY',
  'KEY_DELIVERABLES_LIST',
  'PHASE_N_NAME',
  'PHASE_N_PURPOSE',
  'PHASE_N_DURATION',
  'DEPENDENCIES',
  'PARALLEL_OK',
  'VERIFICATION_COMMANDS',
];

const TASKS_TOKENS = [
  'FEATURE_NAME',
  'VERSION',
  'AUTHOR',
  'DATE',
  'STATUS',
  'PRIORITY',
  'ESTIMATED_EFFORT',
  'RELATED_SPECS',
  'DEPENDENCIES',
  'FEATURE_DISPLAY_NAME',
  'FEATURE_DESCRIPTION',
  'BUSINESS_VALUE',
  'USER_IMPACT',
  'EPIC_NAME',
  'EPIC_GOAL',
  'SUCCESS_CRITERIA',
];

Token Value Sanitization (SEC-SPEC-004):

function sanitizeTokenValue(value) {
  return String(value)
    .replace(/[<>]/g, '') // Prevent HTML injection
    .replace(/\$\{/g, '') // Prevent template literal injection
    .replace(/\{\{/g, '') // Prevent nested token injection
    .trim();
}

Step 2: Read Template

Read the template file using Read or mcpfilesystemread_text_file:

• .claude/templates/specification-template.md (46 tokens)
• .claude/templates/plan-template.md (30+ tokens)
• .claude/templates/tasks-template.md (20+ tokens)

Step 3: Token Replacement

Replace all {{TOKEN}} placeholders with sanitized values:

function renderTemplate(templateContent, tokenMap) {
  let rendered = templateContent;

  // Replace each token
  for (const [token, value] of Object.entries(tokenMap)) {
    // Validate token is in whitelist
    if (!isAllowedToken(token, templateType)) {
      throw new Error(`Token not in whitelist: ${token}`);
    }

    // Sanitize value
    const sanitizedValue = sanitizeTokenValue(value);

    // Replace all occurrences
    const regex = new RegExp(`\\{\\{${token}\\}\\}`, 'g');
    rendered = rendered.replace(regex, sanitizedValue);
  }

  // Check for missing required tokens
  const missingTokens = rendered.match(/\{\{[A-Z_0-9]+\}\}/g);
  if (missingTokens) {
    throw new Error(`Missing required tokens: ${missingTokens.join(', ')}`);
  }

  return rendered;
}

Step 4: Schema Validation (Specification Templates Only)

For specification templates, validate the rendered output against JSON Schema:

// Extract YAML frontmatter
const yamlMatch = rendered.match(/^---\n([\s\S]*?)\n---/);
if (!yamlMatch) {
  throw new Error('No YAML frontmatter found');
}

// Parse YAML
const yaml = require('js-yaml');
const frontmatter = yaml.load(yamlMatch[1]);

// Validate against schema
const schema = JSON.parse(
  fs.readFileSync('.claude/schemas/specification-template.schema.json', 'utf8')
);

const Ajv = require('ajv');
const ajv = new Ajv();
const validate = ajv.compile(schema);

if (!validate(frontmatter)) {
  throw new Error(`Schema validation failed: ${JSON.stringify(validate.errors)}`);
}

Step 5: Write Output

Write the rendered template to the output path using Write or mcpfilesystemwrite_file:

• Verify output path is within PROJECT_ROOT
• Create parent directories if needed
• Write file with UTF-8 encoding

Step 6: Verification

Run post-rendering checks:

# Check no unresolved tokens remain
grep "{{" <output-file> && echo "ERROR: Unresolved tokens found!" || echo "✓ All tokens resolved"

# For specifications: Validate YAML frontmatter
head -50 <output-file> | grep -E "^---$" | wc -l  # Should output: 2

# For specifications: Validate against schema (if ajv installed)
# ajv validate -s .claude/schemas/specification-template.schema.json -d <output-file>

1. Always validate template paths: Use PROJECT_ROOT validation before reading
2. Sanitize all token values: Prevent injection attacks (SEC-SPEC-004)
3. Enforce token whitelist: Only allow predefined tokens (SEC-SPEC-003)
4. Error on missing tokens: Don't silently ignore missing required tokens
5. Warn on unused tokens: Help users catch typos in token names
6. Preserve Markdown formatting: Don't alter indentation, bullets, code blocks
7. Validate schema for specs: Run JSON Schema validation for specification templates
8. Log all operations: Record template, tokens used, output path to memory

Missing Required Tokens:

ERROR: Missing required tokens in template:
  - {{FEATURE_NAME}}
  - {{ACCEPTANCE_CRITERIA_1}}

Provide these tokens in the token map.

Invalid Token (Not in Whitelist):

ERROR: Token not in whitelist: INVALID_TOKEN
Allowed tokens for specification-template: FEATURE_NAME, VERSION, AUTHOR, DATE, ...

Template Path Traversal:

ERROR: Template path outside PROJECT_ROOT
Path: ../../etc/passwd
Only templates from .claude/templates/ are allowed.

Schema Validation Failure (Specification Templates):

ERROR: Schema validation failed:
  - /version: must match pattern "^\d+\.\d+\.\d+$"
  - /acceptance_criteria: must have at least 1 item

Unused Tokens Warning:

WARNING: Unused tokens provided:
  - EXTRA_TOKEN_1
  - EXTRA_TOKEN_2

These tokens are not in the template. Check for typos.

// From another skill (e.g., spec-gathering)
Skill({
  skill: 'template-renderer',
  args: {
    templateName: 'specification-template',
    outputPath: '.claude/context/artifacts/specifications/my-feature-spec.md',
    tokens: {
      FEATURE_NAME: 'User Authentication',
      VERSION: '1.0.0',
      AUTHOR: 'Claude',
      DATE: '2026-01-28',
      STATUS: 'draft',
      ACCEPTANCE_CRITERIA_1: 'User can log in with email and password',
      ACCEPTANCE_CRITERIA_2: 'Password meets complexity requirements',
      ACCEPTANCE_CRITERIA_3: 'Failed login attempts are logged',
    },
  },
});

Example 2: Render Plan Template

Skill({
  skill: 'template-renderer',
  args: {
    templateName: 'plan-template',
    outputPath: '.claude/context/plans/my-feature-plan.md',
    tokens: {
      PLAN_TITLE: 'User Authentication Implementation Plan',
      DATE: '2026-01-28',
      FRAMEWORK_VERSION: 'Agent-Studio v3.1.0',
      STATUS: 'Phase 0 - Research',
      EXECUTIVE_SUMMARY: 'Implementation plan for JWT-based authentication...',
      TOTAL_TASKS: '14 atomic tasks',
      ESTIMATED_TIME: '2-3 weeks',
      STRATEGY: 'Foundation-first (schema) → Core features',
    },
  },
});

Example 3: Render Tasks Template

Skill({
  skill: 'template-renderer',
  args: {
    templateName: 'tasks-template',
    outputPath: '.claude/context/artifacts/tasks/auth-tasks.md',
    tokens: {
      FEATURE_NAME: 'user-authentication',
      VERSION: '1.0.0',
      AUTHOR: 'Engineering Team',
      DATE: '2026-01-28',
      FEATURE_DISPLAY_NAME: 'User Authentication',
      FEATURE_DESCRIPTION: 'JWT-based authentication system',
      BUSINESS_VALUE: 'Enables user account management',
      USER_IMPACT: 'Users can securely access personalized features',
    },
  },
});

Example 4: CLI Usage

# Using CLI wrapper (after implementation in main.cjs)
node .claude/skills/template-renderer/scripts/main.cjs \
  --template specification-template \
  --output ./my-spec.md \
  --tokens '{"FEATURE_NAME":"My Feature","VERSION":"1.0.0","AUTHOR":"Claude","DATE":"2026-01-28"}'

# Or with JSON file
node .claude/skills/template-renderer/scripts/main.cjs \
  --template plan-template \
  --output ./my-plan.md \
  --tokens-file ./tokens.json

Example 5: Integration with spec-gathering

// In spec-gathering skill (Task #16):
// After collecting requirements via progressive disclosure...

const tokens = {
  FEATURE_NAME: gatheredRequirements.featureName,
  VERSION: '1.0.0',
  AUTHOR: 'Claude',
  DATE: new Date().toISOString().split('T')[0],
  ACCEPTANCE_CRITERIA_1: gatheredRequirements.criteria[0],
  ACCEPTANCE_CRITERIA_2: gatheredRequirements.criteria[1],
  ACCEPTANCE_CRITERIA_3: gatheredRequirements.criteria[2],
  // ... more tokens
};

Skill({
  skill: 'template-renderer',
  args: {
    templateName: 'specification-template',
    outputPath: `.claude/context/artifacts/specifications/${featureName}-spec.md`,
    tokens: tokens,
  },
});

Memory Protocol (MANDATORY)

Before starting:

cat .claude/context/memory/learnings.md

After completing:

• New pattern -> .claude/context/memory/learnings.md
• Issue found -> .claude/context/memory/issues.md
• Decision made -> .claude/context/memory/decisions.md

ASSUME INTERRUPTION: Your context may reset. If it's not in memory, it didn't happen.