Validation Rules

MRS uses progressive validation to catch errors before state mutation, provide specific feedback, and enable partial application when appropriate. See: /MRS-Specification-RFC#13-progressive-validation

Validation Pipeline

┌─────────────┐   ┌─────────────┐   ┌─────────────┐   ┌─────────────┐
│   Syntax    │ → │ References  │ → │ Permissions │ → │  Musical    │
│ Validation  │   │ Validation  │   │ Validation  │   │  Rules      │
└─────────────┘   └─────────────┘   └─────────────┘   └─────────────┘

Operations are validated in stages. Each stage must pass before proceeding to the next.

Stage 1: Syntax Validation

Verifies operations are well-formed.

Check	Description
Operation type	Recognized operation (create-event, update-event, etc.)
Required fields	All required fields present
Field types	Values have correct types
Rational format	Beat positions are valid rationals

Syntax Errors

Code	Description
SYN-001	Unknown operation type
SYN-002	Missing required field
SYN-003	Invalid field type
SYN-004	Malformed rational number
SYN-005	Invalid tmp-id format

Stage 2: Reference Validation

Verifies all references are valid.

Check	Description
UUID existence	Referenced UUIDs exist in source
Tmp-id uniqueness	All tmp-ids unique within envelope
Cross-references	Ops can reference each other’s tmp-ids
Measure reference	Target measure exists

Reference Errors

Code	Description
REF-001	UUID not found in source
REF-002	Duplicate tmp-id
REF-003	Tmp-id referenced but not defined
REF-004	Circular reference

Stage 3: Permission Validation

Verifies operations are within granted permissions.

Check	Description
Operation allowed	Op type in `:allowed-ops` list
Lane permission	Content within granted lanes
Scope bounds	Targets within granted scope
Lock respect	Not modifying locked lanes

Permission Errors

Code	Description
PERM-001	Operation type not allowed
PERM-002	Lane not granted
PERM-003	Outside granted scope
PERM-004	Modifying locked lane

Stage 4: Musical Rule Validation

Verifies musical constraints are satisfied.

Structural Rules

Rule	Severity	Description
STRUCT-001	ERROR	Would create duplicate UUID
STRUCT-002	ERROR	Invalid measure number
STRUCT-003	ERROR	Beat position out of bounds
STRUCT-004	ERROR	Duration overflow (exceeds measure)
STRUCT-005	WARNING	Gap in measure numbering

Musical Rules

Rule	Severity	Description
MUSIC-001	ERROR	Tie connects different pitches
MUSIC-002	ERROR	Span endpoints reversed (from > to)
MUSIC-003	WARNING	Pitch out of instrument range
MUSIC-004	WARNING	Parallel fifths/octaves
MUSIC-005	WARNING	Voice crossing
MUSIC-006	WARNING	Large melodic leap (> octave)

Constraint Rules

Rule	Severity	Description
CONST-001	ERROR	Violates range constraint
CONST-002	WARNING	Violates avoid constraint
CONST-003	INFO	Does not satisfy prefer constraint

Severity Levels

Level	Meaning	Action
ERROR	Invalid; cannot apply	Operation rejected
WARNING	Suspicious; may be intentional	Apply with warning
INFO	Informational; style suggestion	Apply; log info

Validation Results

All Pass

(validation-result
  :status passed
  :warnings []
  :info [])

Errors Found

(validation-result
  :status rejected
  :stage permissions
  :errors
    ((error :op 3 :code PERM-001 
            :message "Operation 'create-measure' not in allowed-ops"
            :detail (:allowed [create-event update-event delete-event]))))

Warnings Only

(validation-result
  :status passed-with-warnings
  :warnings
    ((warning :op 2 :code MUSIC-003
              :message "Pitch D7 exceeds clarinet-bb range [E3 C7]")))

Constraint Validation

Constraints from the Working Set Envelope are checked in Stage 4.

Range Constraint

(range clarinet-bb E3 C7)

Checks all pitches for clarinet-bb are within E3-C7.

Avoid Constraint

(avoid parallel-fifths violin-1)

Checks for parallel fifths between the modified part and violin-1.

Prefer Constraint

(prefer chord-tones downbeats)

Checks if downbeat notes are chord tones. Generates INFO if not satisfied.

Density Constraint

(note-density 2 8)

Checks notes per measure is between 2 and 8.

Partial Application

When some operations fail:

Policy	Behavior
`all-or-nothing`	Reject entire batch on any error
`partial`	Apply valid ops; return errors for invalid
`interactive`	Pause and await human decision

(mrs-ops-result
  :status partial
  :applied 4
  :rejected 2
  :id-mapping (...)
  :errors
    ((error :op 5 :code MUSIC-001 :message "...")
     (error :op 6 :code REF-003 :message "...")))

Overview

MRS-S Format

Agent Workflows

Model & Validation

Validation Pipeline

Stage 1: Syntax Validation

Syntax Errors

Stage 2: Reference Validation

Reference Errors

Stage 3: Permission Validation

Permission Errors

Stage 4: Musical Rule Validation

Structural Rules

Musical Rules

Constraint Rules

Severity Levels

Validation Results

All Pass

Errors Found

Warnings Only

Constraint Validation

Range Constraint

Avoid Constraint

Prefer Constraint

Density Constraint

Partial Application

Best Practices

For Agent Implementers

For Orchestrator Implementers

Overview

MRS-S Format

Agent Workflows

Model & Validation

​Validation Pipeline

​Stage 1: Syntax Validation

​Syntax Errors

​Stage 2: Reference Validation

​Reference Errors

​Stage 3: Permission Validation

​Permission Errors

​Stage 4: Musical Rule Validation

​Structural Rules

​Musical Rules

​Constraint Rules

​Severity Levels

​Validation Results

​All Pass

​Errors Found

​Warnings Only

​Constraint Validation

​Range Constraint

​Avoid Constraint

​Prefer Constraint

​Density Constraint

​Partial Application

​Best Practices

​For Agent Implementers

​For Orchestrator Implementers

Validation Pipeline

Stage 1: Syntax Validation

Syntax Errors

Stage 2: Reference Validation

Reference Errors

Stage 3: Permission Validation

Permission Errors

Stage 4: Musical Rule Validation

Structural Rules

Musical Rules

Constraint Rules

Severity Levels

Validation Results

All Pass

Errors Found

Warnings Only

Constraint Validation

Range Constraint

Avoid Constraint

Prefer Constraint

Density Constraint

Partial Application

Best Practices

For Agent Implementers

For Orchestrator Implementers