diff --git a/appview/ingester.go b/appview/ingester.go
--- a/appview/ingester.go
+++ b/appview/ingester.go
@@ -19,7 +19,6 @@ "tangled.org/core/appview/config"
 	"tangled.org/core/appview/db"
 	"tangled.org/core/appview/models"
 	"tangled.org/core/appview/serververify"
-	"tangled.org/core/appview/validator"
 	"tangled.org/core/idresolver"
 	"tangled.org/core/orm"
 	"tangled.org/core/rbac"
@@ -31,7 +30,6 @@ Enforcer   *rbac.Enforcer
 	IdResolver *idresolver.Resolver
 	Config     *config.Config
 	Logger     *slog.Logger
-	Validator  *validator.Validator
 }
 
 type processFunc func(ctx context.Context, e *jmodels.Event) error
@@ -613,7 +611,7 @@ }
 
 		string := models.StringFromRecord(did, rkey, record)
 
-		if err = i.Validator.ValidateString(&string); err != nil {
+		if err = string.Validate(); err != nil {
 			l.Error("invalid record", "err", err)
 			return err
 		}
@@ -822,7 +820,7 @@ }
 
 		issue := models.IssueFromRecord(did, rkey, record)
 
-		if err := i.Validator.ValidateIssue(&issue); err != nil {
+		if err := issue.Validate(); err != nil {
 			return fmt.Errorf("failed to validate issue: %w", err)
 		}
 
@@ -902,7 +900,7 @@ if err != nil {
 			return fmt.Errorf("failed to parse comment from record: %w", err)
 		}
 
-		if err := i.Validator.ValidateIssueComment(comment); err != nil {
+		if err := comment.Validate(); err != nil {
 			return fmt.Errorf("failed to validate comment: %w", err)
 		}
 
@@ -962,7 +960,7 @@ if err != nil {
 			return fmt.Errorf("failed to parse labeldef from record: %w", err)
 		}
 
-		if err := i.Validator.ValidateLabelDefinition(def); err != nil {
+		if err := def.Validate(); err != nil {
 			return fmt.Errorf("failed to validate labeldef: %w", err)
 		}
 
@@ -1038,7 +1036,19 @@ def, ok := actx.Defs[o.OperandKey]
 			if !ok {
 				return fmt.Errorf("failed to find label def for key: %s, expected: %q", o.OperandKey, slices.Collect(maps.Keys(actx.Defs)))
 			}
-			if err := i.Validator.ValidateLabelOp(def, repo, &o); err != nil {
+
+			// validate permissions: only collaborators can apply labels currently
+			//
+			// TODO: introduce a repo:triage permission
+			ok, err := i.Enforcer.IsPushAllowed(o.Did, repo.Knot, repo.DidSlashRepo())
+			if err != nil {
+				return fmt.Errorf("enforcing permission: %w", err)
+			}
+			if !ok {
+				return fmt.Errorf("unauthorized label operation")
+			}
+
+			if err := def.ValidateOperandValue(&o); err != nil {
 				return fmt.Errorf("failed to validate labelop: %w", err)
 			}
 		}
diff --git a/appview/issues/issues.go b/appview/issues/issues.go
--- a/appview/issues/issues.go
+++ b/appview/issues/issues.go
@@ -28,7 +28,6 @@ "tangled.org/core/appview/pages/repoinfo"
 	"tangled.org/core/appview/pagination"
 	"tangled.org/core/appview/reporesolver"
 	"tangled.org/core/appview/searchquery"
-	"tangled.org/core/appview/validator"
 	"tangled.org/core/idresolver"
 	"tangled.org/core/orm"
 	"tangled.org/core/rbac"
@@ -46,7 +45,6 @@ db               *db.DB
 	config           *config.Config
 	notifier         notify.Notifier
 	logger           *slog.Logger
-	validator        *validator.Validator
 	indexer          *issues_indexer.Indexer
 }
 
@@ -60,7 +58,6 @@ mentionsResolver *mentions.Resolver,
 	db *db.DB,
 	config *config.Config,
 	notifier notify.Notifier,
-	validator *validator.Validator,
 	indexer *issues_indexer.Indexer,
 	logger *slog.Logger,
 ) *Issues {
@@ -75,7 +72,6 @@ db:               db,
 		config:           config,
 		notifier:         notifier,
 		logger:           logger,
-		validator:        validator,
 		indexer:          indexer,
 	}
 }
@@ -166,7 +162,7 @@ newIssue.Title = r.FormValue("title")
 		newIssue.Body = r.FormValue("body")
 		newIssue.Mentions, newIssue.References = rp.mentionsResolver.Resolve(r.Context(), newIssue.Body)
 
-		if err := rp.validator.ValidateIssue(newIssue); err != nil {
+		if err := newIssue.Validate(); err != nil {
 			l.Error("validation error", "err", err)
 			rp.pages.Notice(w, noticeId, fmt.Sprintf("Failed to edit issue: %s", err))
 			return
@@ -425,7 +421,7 @@ Created:    time.Now(),
 		Mentions:   mentions,
 		References: references,
 	}
-	if err = rp.validator.ValidateIssueComment(&comment); err != nil {
+	if err = comment.Validate(); err != nil {
 		l.Error("failed to validate comment", "err", err)
 		rp.pages.Notice(w, "issue-comment", "Failed to create comment.")
 		return
@@ -1022,7 +1018,7 @@ References: references,
 			Repo:       f,
 		}
 
-		if err := rp.validator.ValidateIssue(issue); err != nil {
+		if err := issue.Validate(); err != nil {
 			l.Error("validation error", "err", err)
 			rp.pages.Notice(w, "issues", fmt.Sprintf("Failed to create issue: %s", err))
 			return
diff --git a/appview/labels/labels.go b/appview/labels/labels.go
--- a/appview/labels/labels.go
+++ b/appview/labels/labels.go
@@ -16,7 +16,6 @@ "tangled.org/core/appview/models"
 	"tangled.org/core/appview/notify"
 	"tangled.org/core/appview/oauth"
 	"tangled.org/core/appview/pages"
-	"tangled.org/core/appview/validator"
 	"tangled.org/core/orm"
 	"tangled.org/core/rbac"
 	"tangled.org/core/tid"
@@ -29,32 +28,29 @@ "github.com/go-chi/chi/v5"
 )
 
 type Labels struct {
-	oauth     *oauth.OAuth
-	pages     *pages.Pages
-	db        *db.DB
-	logger    *slog.Logger
-	validator *validator.Validator
-	enforcer  *rbac.Enforcer
-	notifier  notify.Notifier
+	oauth    *oauth.OAuth
+	pages    *pages.Pages
+	db       *db.DB
+	logger   *slog.Logger
+	enforcer *rbac.Enforcer
+	notifier notify.Notifier
 }
 
 func New(
 	oauth *oauth.OAuth,
 	pages *pages.Pages,
 	db *db.DB,
-	validator *validator.Validator,
 	enforcer *rbac.Enforcer,
 	notifier notify.Notifier,
 	logger *slog.Logger,
 ) *Labels {
 	return &Labels{
-		oauth:     oauth,
-		pages:     pages,
-		db:        db,
-		logger:    logger,
-		validator: validator,
-		enforcer:  enforcer,
-		notifier:  notifier,
+		oauth:    oauth,
+		pages:    pages,
+		db:       db,
+		logger:   logger,
+		enforcer: enforcer,
+		notifier: notifier,
 	}
 }
 
@@ -167,10 +163,26 @@ }
 
 	for i := range labelOps {
 		def := actx.Defs[labelOps[i].OperandKey]
-		if err := l.validator.ValidateLabelOp(def, repo, &labelOps[i]); err != nil {
+		op := labelOps[i]
+
+		// validate permissions: only collaborators can apply labels currently
+		//
+		// TODO: introduce a repo:triage permission
+		ok, err := l.enforcer.IsPushAllowed(op.Did, repo.Knot, repo.DidSlashRepo())
+		if err != nil {
+			fail("Failed to enforce permissions. Please try again later", fmt.Errorf("enforcing permission: %w", err))
+			return
+		}
+		if !ok {
+			fail("Unauthorized label operation", fmt.Errorf("unauthorized label operation"))
+			return
+		}
+
+		if err := def.ValidateOperandValue(&op); err != nil {
 			fail(fmt.Sprintf("Invalid form data: %s", err), err)
 			return
 		}
+		labelOps[i] = op
 	}
 
 	// reduce the opset
diff --git a/appview/models/issue.go b/appview/models/issue.go
--- a/appview/models/issue.go
+++ b/appview/models/issue.go
@@ -3,10 +3,12 @@
 import (
 	"fmt"
 	"sort"
+	"strings"
 	"time"
 
 	"github.com/bluesky-social/indigo/atproto/syntax"
 	"tangled.org/core/api/tangled"
+	"tangled.org/core/appview/pages/markup/sanitizer"
 )
 
 type Issue struct {
@@ -59,6 +61,26 @@ if i.Open {
 		return "open"
 	}
 	return "closed"
+}
+
+var _ Validator = new(Issue)
+
+func (i *Issue) Validate() error {
+	if i.Title == "" {
+		return fmt.Errorf("issue title is empty")
+	}
+	if i.Body == "" {
+		return fmt.Errorf("issue body is empty")
+	}
+
+	if st := strings.TrimSpace(sanitizer.SanitizeDescription(i.Title)); st == "" {
+		return fmt.Errorf("title is empty after HTML sanitization")
+	}
+
+	if st := strings.TrimSpace(sanitizer.SanitizeDefault(i.Body)); st == "" {
+		return fmt.Errorf("body is empty after HTML sanitization")
+	}
+	return nil
 }
 
 type CommentListItem struct {
@@ -215,6 +237,16 @@ }
 
 func (i *IssueComment) IsReply() bool {
 	return i.ReplyTo != nil
+}
+
+var _ Validator = new(IssueComment)
+
+func (i *IssueComment) Validate() error {
+	if sb := strings.TrimSpace(sanitizer.SanitizeDefault(i.Body)); sb == "" {
+		return fmt.Errorf("body is empty after HTML sanitization")
+	}
+
+	return nil
 }
 
 func IssueCommentFromRecord(did, rkey string, record tangled.RepoIssueComment) (*IssueComment, error) {
diff --git a/appview/models/label.go b/appview/models/label.go
--- a/appview/models/label.go
+++ b/appview/models/label.go
@@ -7,7 +7,9 @@ "encoding/hex"
 	"encoding/json"
 	"errors"
 	"fmt"
+	"regexp"
 	"slices"
+	"strings"
 	"time"
 
 	"github.com/bluesky-social/indigo/api/atproto"
@@ -120,6 +122,167 @@ ValueType: &vt,
 	}
 }
 
+var (
+	// Label name should be alphanumeric with hyphens/underscores, but not start/end with them
+	labelNameRegex = regexp.MustCompile(`^[a-zA-Z0-9]([a-zA-Z0-9_-]*[a-zA-Z0-9])?$`)
+	// Color should be a valid hex color
+	colorRegex = regexp.MustCompile(`^#[a-fA-F0-9]{6}$`)
+	// You can only label issues and pulls presently
+	validScopes = []string{tangled.RepoIssueNSID, tangled.RepoPullNSID}
+)
+
+var _ Validator = new(LabelDefinition)
+
+func (l *LabelDefinition) Validate() error {
+	if l.Name == "" {
+		return fmt.Errorf("label name is empty")
+	}
+	if len(l.Name) > 40 {
+		return fmt.Errorf("label name too long (max 40 graphemes)")
+	}
+	if len(l.Name) < 1 {
+		return fmt.Errorf("label name too short (min 1 grapheme)")
+	}
+	if !labelNameRegex.MatchString(l.Name) {
+		return fmt.Errorf("label name contains invalid characters (use only letters, numbers, hyphens, and underscores)")
+	}
+
+	if !l.ValueType.IsConcreteType() {
+		return fmt.Errorf("invalid value type: %q (must be one of: null, boolean, integer, string)", l.ValueType.Type)
+	}
+
+	// null type checks: cannot be enums, multiple or explicit format
+	if l.ValueType.IsNull() && l.ValueType.IsEnum() {
+		return fmt.Errorf("null type cannot be used in conjunction with enum type")
+	}
+	if l.ValueType.IsNull() && l.Multiple {
+		return fmt.Errorf("null type labels cannot be multiple")
+	}
+	if l.ValueType.IsNull() && !l.ValueType.IsAnyFormat() {
+		return fmt.Errorf("format cannot be used in conjunction with null type")
+	}
+
+	// format checks: cannot be used with enum, or integers
+	if !l.ValueType.IsAnyFormat() && l.ValueType.IsEnum() {
+		return fmt.Errorf("enum types cannot be used in conjunction with format specification")
+	}
+
+	if !l.ValueType.IsAnyFormat() && !l.ValueType.IsString() {
+		return fmt.Errorf("format specifications are only permitted on string types")
+	}
+
+	// validate scope (nsid format)
+	if l.Scope == nil {
+		return fmt.Errorf("scope is required")
+	}
+	for _, s := range l.Scope {
+		if _, err := syntax.ParseNSID(s); err != nil {
+			return fmt.Errorf("failed to parse scope: %w", err)
+		}
+		if !slices.Contains(validScopes, s) {
+			return fmt.Errorf("invalid scope: scope must be present in %q", validScopes)
+		}
+	}
+
+	// validate color if provided
+	if l.Color != nil {
+		color := strings.TrimSpace(*l.Color)
+		if color == "" {
+			// empty color is fine, set to nil
+			l.Color = nil
+		} else {
+			if !colorRegex.MatchString(color) {
+				return fmt.Errorf("color must be a valid hex color (e.g. #79FFE1 or #000)")
+			}
+			// expand 3-digit hex to 6-digit hex
+			if len(color) == 4 { // #ABC
+				color = fmt.Sprintf("#%c%c%c%c%c%c", color[1], color[1], color[2], color[2], color[3], color[3])
+			}
+			// convert to uppercase for consistency
+			color = strings.ToUpper(color)
+			l.Color = &color
+		}
+	}
+
+	return nil
+}
+
+// ValidateOperandValue validates the label operation operand value based on
+// label definition.
+//
+// NOTE: This can modify the [LabelOp]
+func (def *LabelDefinition) ValidateOperandValue(op *LabelOp) error {
+	expectedKey := def.AtUri().String()
+	if op.OperandKey != def.AtUri().String() {
+		return fmt.Errorf("operand key %q does not match label definition URI %q", op.OperandKey, expectedKey)
+	}
+
+	valueType := def.ValueType
+
+	// this is permitted, it "unsets" a label
+	if op.OperandValue == "" {
+		op.Operation = LabelOperationDel
+		return nil
+	}
+
+	switch valueType.Type {
+	case ConcreteTypeNull:
+		// For null type, value should be empty
+		if op.OperandValue != "null" {
+			return fmt.Errorf("null type requires empty value, got %q", op.OperandValue)
+		}
+
+	case ConcreteTypeString:
+		// For string type, validate enum constraints if present
+		if valueType.IsEnum() {
+			if !slices.Contains(valueType.Enum, op.OperandValue) {
+				return fmt.Errorf("value %q is not in allowed enum values %v", op.OperandValue, valueType.Enum)
+			}
+		}
+
+		switch valueType.Format {
+		case ValueTypeFormatDid:
+			if _, err := syntax.ParseDID(op.OperandValue); err != nil {
+				return fmt.Errorf("failed to resolve did/handle: %w", err)
+			}
+		case ValueTypeFormatAny, "":
+		default:
+			return fmt.Errorf("unsupported format constraint: %q", valueType.Format)
+		}
+
+	case ConcreteTypeInt:
+		if op.OperandValue == "" {
+			return fmt.Errorf("integer type requires non-empty value")
+		}
+		if _, err := fmt.Sscanf(op.OperandValue, "%d", new(int)); err != nil {
+			return fmt.Errorf("value %q is not a valid integer", op.OperandValue)
+		}
+
+		if valueType.IsEnum() {
+			if !slices.Contains(valueType.Enum, op.OperandValue) {
+				return fmt.Errorf("value %q is not in allowed enum values %v", op.OperandValue, valueType.Enum)
+			}
+		}
+
+	case ConcreteTypeBool:
+		if op.OperandValue != "true" && op.OperandValue != "false" {
+			return fmt.Errorf("boolean type requires value to be 'true' or 'false', got %q", op.OperandValue)
+		}
+
+		// validate enum constraints if present (though uncommon for booleans)
+		if valueType.IsEnum() {
+			if !slices.Contains(valueType.Enum, op.OperandValue) {
+				return fmt.Errorf("value %q is not in allowed enum values %v", op.OperandValue, valueType.Enum)
+			}
+		}
+
+	default:
+		return fmt.Errorf("unsupported value type: %q", valueType.Type)
+	}
+
+	return nil
+}
+
 // random color for a given seed
 func randomColor(seed string) string {
 	hash := sha1.Sum([]byte(seed))
@@ -131,14 +294,14 @@
 	return fmt.Sprintf("#%s%s%s", r, g, b)
 }
 
-func (ld LabelDefinition) GetColor() string {
-	if ld.Color == nil {
-		seed := fmt.Sprintf("%d:%s:%s", ld.Id, ld.Did, ld.Rkey)
+func (l LabelDefinition) GetColor() string {
+	if l.Color == nil {
+		seed := fmt.Sprintf("%d:%s:%s", l.Id, l.Did, l.Rkey)
 		color := randomColor(seed)
 		return color
 	}
 
-	return *ld.Color
+	return *l.Color
 }
 
 func LabelDefinitionFromRecord(did, rkey string, record tangled.LabelDefinition) (*LabelDefinition, error) {
@@ -203,6 +366,22 @@ }
 
 	// otherwise, createdat is in the future relative to indexedat -> use indexedat
 	return indexedAt
+}
+
+var _ Validator = new(LabelOp)
+
+func (l *LabelOp) Validate() error {
+	if _, err := syntax.ParseATURI(string(l.Subject)); err != nil {
+		return fmt.Errorf("invalid subject URI: %w", err)
+	}
+	if l.Operation != LabelOperationAdd && l.Operation != LabelOperationDel {
+		return fmt.Errorf("invalid operation: %q (must be 'add' or 'del')", l.Operation)
+	}
+	// Validate performed time is not zero/invalid
+	if l.PerformedAt.IsZero() {
+		return fmt.Errorf("performed_at timestamp is required")
+	}
+	return nil
 }
 
 type LabelOperation string
diff --git a/appview/models/string.go b/appview/models/string.go
--- a/appview/models/string.go
+++ b/appview/models/string.go
@@ -2,10 +2,12 @@ package models
 
 import (
 	"bytes"
+	"errors"
 	"fmt"
 	"io"
 	"strings"
 	"time"
+	"unicode/utf8"
 
 	"github.com/bluesky-social/indigo/atproto/syntax"
 	"tangled.org/core/api/tangled"
@@ -33,6 +35,25 @@ Description: s.Description,
 		Contents:    s.Contents,
 		CreatedAt:   s.Created.Format(time.RFC3339),
 	}
+}
+
+var _ Validator = new(String)
+
+func (s *String) Validate() error {
+	var err error
+	if utf8.RuneCountInString(s.Filename) > 140 {
+		err = errors.Join(err, fmt.Errorf("filename too long"))
+	}
+
+	if utf8.RuneCountInString(s.Description) > 280 {
+		err = errors.Join(err, fmt.Errorf("description too long"))
+	}
+
+	if len(s.Contents) == 0 {
+		err = errors.Join(err, fmt.Errorf("contents is empty"))
+	}
+
+	return err
 }
 
 func StringFromRecord(did, rkey string, record tangled.String) String {
diff --git a/appview/models/validator.go b/appview/models/validator.go
new file mode 100644
--- /dev/null
+++ b/appview/models/validator.go
@@ -0,0 +1,6 @@
+package models
+
+type Validator interface {
+	// Validate checks the object and returns any error.
+	Validate() error
+}
diff --git a/appview/pages/funcmap.go b/appview/pages/funcmap.go
--- a/appview/pages/funcmap.go
+++ b/appview/pages/funcmap.go
@@ -31,6 +31,7 @@ "tangled.org/core/appview/db"
 	"tangled.org/core/appview/models"
 	"tangled.org/core/appview/oauth"
 	"tangled.org/core/appview/pages/markup"
+	"tangled.org/core/appview/pages/markup/sanitizer"
 	"tangled.org/core/crypto"
 )
 
@@ -264,7 +265,7 @@ },
 		"markdown": func(text string) template.HTML {
 			p.rctx.RendererType = markup.RendererTypeDefault
 			htmlString := p.rctx.RenderMarkdown(text)
-			sanitized := p.rctx.SanitizeDefault(htmlString)
+			sanitized := sanitizer.SanitizeDefault(htmlString)
 			return template.HTML(sanitized)
 		},
 		"description": func(text string) template.HTML {
@@ -274,13 +275,13 @@ goldmark.WithExtensions(
 					emoji.Emoji,
 				),
 			))
-			sanitized := p.rctx.SanitizeDescription(htmlString)
+			sanitized := sanitizer.SanitizeDescription(htmlString)
 			return template.HTML(sanitized)
 		},
 		"readme": func(text string) template.HTML {
 			p.rctx.RendererType = markup.RendererTypeRepoMarkdown
 			htmlString := p.rctx.RenderMarkdown(text)
-			sanitized := p.rctx.SanitizeDefault(htmlString)
+			sanitized := sanitizer.SanitizeDefault(htmlString)
 			return template.HTML(sanitized)
 		},
 		"code": func(content, path string) string {
diff --git a/appview/pages/markup/markdown.go b/appview/pages/markup/markdown.go
--- a/appview/pages/markup/markdown.go
+++ b/appview/pages/markup/markdown.go
@@ -49,7 +49,6 @@ repoinfo.RepoInfo
 	IsDev        bool
 	Hostname     string
 	RendererType RendererType
-	Sanitizer    Sanitizer
 	Files        fs.FS
 }
 
@@ -182,14 +181,6 @@ visitNode(ctx, n)
 		}
 	default:
 	}
-}
-
-func (rctx *RenderContext) SanitizeDefault(html string) string {
-	return rctx.Sanitizer.SanitizeDefault(html)
-}
-
-func (rctx *RenderContext) SanitizeDescription(html string) string {
-	return rctx.Sanitizer.SanitizeDescription(html)
 }
 
 type MarkdownTransformer struct {
diff --git a/appview/pages/markup/sanitizer.go b/appview/pages/markup/sanitizer/sanitizer.go
rename from appview/pages/markup/sanitizer.go
rename to appview/pages/markup/sanitizer/sanitizer.go
--- a/appview/pages/markup/sanitizer.go
+++ b/appview/pages/markup/sanitizer/sanitizer.go
@@ -1,4 +1,4 @@
-package markup
+package sanitizer
 
 import (
 	"maps"
@@ -21,23 +21,11 @@ sharedDefaultPolicy = buildDefaultPolicy()
 	sharedDescriptionPolicy = buildDescriptionPolicy()
 }
 
-type Sanitizer struct {
-	defaultPolicy     *bluemonday.Policy
-	descriptionPolicy *bluemonday.Policy
-}
-
-func NewSanitizer() Sanitizer {
-	return Sanitizer{
-		defaultPolicy:     sharedDefaultPolicy,
-		descriptionPolicy: sharedDescriptionPolicy,
-	}
-}
-
-func (s *Sanitizer) SanitizeDefault(html string) string {
-	return s.defaultPolicy.Sanitize(html)
+func SanitizeDefault(html string) string {
+	return sharedDefaultPolicy.Sanitize(html)
 }
-func (s *Sanitizer) SanitizeDescription(html string) string {
-	return s.descriptionPolicy.Sanitize(html)
+func SanitizeDescription(html string) string {
+	return sharedDescriptionPolicy.Sanitize(html)
 }
 
 func buildDefaultPolicy() *bluemonday.Policy {
diff --git a/appview/pages/pages.go b/appview/pages/pages.go
--- a/appview/pages/pages.go
+++ b/appview/pages/pages.go
@@ -23,6 +23,7 @@ "tangled.org/core/appview/db"
 	"tangled.org/core/appview/models"
 	"tangled.org/core/appview/oauth"
 	"tangled.org/core/appview/pages/markup"
+	"tangled.org/core/appview/pages/markup/sanitizer"
 	"tangled.org/core/appview/pages/repoinfo"
 	"tangled.org/core/appview/pagination"
 	"tangled.org/core/idresolver"
@@ -58,7 +59,6 @@ IsDev:      config.Core.Dev,
 		Hostname:   config.Core.AppviewHost,
 		CamoUrl:    config.Camo.Host,
 		CamoSecret: config.Camo.SharedSecret,
-		Sanitizer:  markup.NewSanitizer(),
 		Files:      Files,
 	}
 
@@ -293,7 +293,7 @@ }
 
 	p.rctx.RendererType = markup.RendererTypeDefault
 	htmlString := p.rctx.RenderMarkdown(string(markdownBytes))
-	sanitized := p.rctx.SanitizeDefault(htmlString)
+	sanitized := sanitizer.SanitizeDefault(htmlString)
 	params.Content = template.HTML(sanitized)
 
 	return p.execute("legal/terms", w, params)
@@ -321,7 +321,7 @@ }
 
 	p.rctx.RendererType = markup.RendererTypeDefault
 	htmlString := p.rctx.RenderMarkdown(string(markdownBytes))
-	sanitized := p.rctx.SanitizeDefault(htmlString)
+	sanitized := sanitizer.SanitizeDefault(htmlString)
 	params.Content = template.HTML(sanitized)
 
 	return p.execute("legal/privacy", w, params)
@@ -744,7 +744,7 @@ switch ext {
 		case ".md", ".markdown", ".mdown", ".mkdn", ".mkd":
 			params.Raw = false
 			htmlString := p.rctx.RenderMarkdown(params.Readme)
-			sanitized := p.rctx.SanitizeDefault(htmlString)
+			sanitized := sanitizer.SanitizeDefault(htmlString)
 			params.HTMLReadme = template.HTML(sanitized)
 		default:
 			params.Raw = true
@@ -837,7 +837,7 @@ switch ext {
 		case ".md", ".markdown", ".mdown", ".mkdn", ".mkd":
 			params.Raw = false
 			htmlString := p.rctx.RenderMarkdown(params.Readme)
-			sanitized := p.rctx.SanitizeDefault(htmlString)
+			sanitized := sanitizer.SanitizeDefault(htmlString)
 			params.HTMLReadme = template.HTML(sanitized)
 		default:
 			params.Raw = true
diff --git a/appview/pulls/pulls.go b/appview/pulls/pulls.go
--- a/appview/pulls/pulls.go
+++ b/appview/pulls/pulls.go
@@ -27,12 +27,11 @@ "tangled.org/core/appview/models"
 	"tangled.org/core/appview/notify"
 	"tangled.org/core/appview/oauth"
 	"tangled.org/core/appview/pages"
-	"tangled.org/core/appview/pages/markup"
+	"tangled.org/core/appview/pages/markup/sanitizer"
 	"tangled.org/core/appview/pages/repoinfo"
 	"tangled.org/core/appview/pagination"
 	"tangled.org/core/appview/reporesolver"
 	"tangled.org/core/appview/searchquery"
-	"tangled.org/core/appview/validator"
 	"tangled.org/core/appview/xrpcclient"
 	"tangled.org/core/idresolver"
 	"tangled.org/core/orm"
@@ -63,7 +62,6 @@ config           *config.Config
 	notifier         notify.Notifier
 	enforcer         *rbac.Enforcer
 	logger           *slog.Logger
-	validator        *validator.Validator
 	indexer          *pulls_indexer.Indexer
 }
 
@@ -77,7 +75,6 @@ db *db.DB,
 	config *config.Config,
 	notifier notify.Notifier,
 	enforcer *rbac.Enforcer,
-	validator *validator.Validator,
 	indexer *pulls_indexer.Indexer,
 	logger *slog.Logger,
 ) *Pulls {
@@ -92,7 +89,6 @@ config:           config,
 		notifier:         notifier,
 		enforcer:         enforcer,
 		logger:           logger,
-		validator:        validator,
 		indexer:          indexer,
 	}
 }
@@ -975,7 +971,6 @@ if title == "" {
 				s.pages.Notice(w, "pull", "Title is required for git-diff patches.")
 				return
 			}
-			sanitizer := markup.NewSanitizer()
 			if st := strings.TrimSpace(sanitizer.SanitizeDescription(title)); (st) == "" {
 				s.pages.Notice(w, "pull", "Title is empty after HTML sanitization")
 				return
@@ -1103,7 +1098,7 @@ sourceRev := comparison.Rev2
 	patch := comparison.FormatPatchRaw
 	combined := comparison.CombinedPatchRaw
 
-	if err := s.validator.ValidatePatch(&patch); err != nil {
+	if err := validatePatch(&patch); err != nil {
 		s.logger.Error("failed to validate patch", "err", err)
 		s.pages.Notice(w, "pull", "Invalid patch format. Please provide a valid diff.")
 		return
@@ -1121,7 +1116,7 @@ s.createPullRequest(w, r, repo, user, title, body, targetBranch, patch, combined, sourceRev, pullSource, recordPullSource, isStacked)
 }
 
 func (s *Pulls) handlePatchBasedPull(w http.ResponseWriter, r *http.Request, repo *models.Repo, user *oauth.MultiAccountUser, title, body, targetBranch, patch string, isStacked bool) {
-	if err := s.validator.ValidatePatch(&patch); err != nil {
+	if err := validatePatch(&patch); err != nil {
 		s.logger.Error("patch validation failed", "err", err)
 		s.pages.Notice(w, "pull", "Invalid patch format. Please provide a valid diff.")
 		return
@@ -1213,7 +1208,7 @@ sourceRev := comparison.Rev2
 	patch := comparison.FormatPatchRaw
 	combined := comparison.CombinedPatchRaw
 
-	if err := s.validator.ValidatePatch(&patch); err != nil {
+	if err := validatePatch(&patch); err != nil {
 		s.logger.Error("failed to validate patch", "err", err)
 		s.pages.Notice(w, "pull", "Invalid patch format. Please provide a valid diff.")
 		return
@@ -1506,7 +1501,7 @@ s.pages.Notice(w, "patch-error", "Patch is required.")
 		return
 	}
 
-	if err := s.validator.ValidatePatch(&patch); err != nil {
+	if err := validatePatch(&patch); err != nil {
 		s.logger.Error("faield to validate patch", "err", err)
 		s.pages.Notice(w, "patch-error", "Invalid patch format. Please provide a valid git diff or format-patch.")
 		return
@@ -1927,7 +1922,7 @@ s.resubmitStackedPullHelper(w, r, repo, user, pull, patch, pull.StackId)
 		return
 	}
 
-	if err := s.validator.ValidatePatch(&patch); err != nil {
+	if err := validatePatch(&patch); err != nil {
 		s.pages.Notice(w, "resubmit-error", err.Error())
 		return
 	}
@@ -2559,3 +2554,20 @@ return &b
 }
 
 func ptrPullState(s models.PullState) *models.PullState { return &s }
+
+func validatePatch(patch *string) error {
+	if patch == nil || *patch == "" {
+		return fmt.Errorf("patch is empty")
+	}
+
+	// add newline if not present to diff style patches
+	if !patchutil.IsFormatPatch(*patch) && !strings.HasSuffix(*patch, "\n") {
+		*patch = *patch + "\n"
+	}
+
+	if err := patchutil.IsPatchValid(*patch); err != nil {
+		return err
+	}
+
+	return nil
+}
diff --git a/appview/repo/repo.go b/appview/repo/repo.go
--- a/appview/repo/repo.go
+++ b/appview/repo/repo.go
@@ -22,7 +22,6 @@ "tangled.org/core/appview/notify"
 	"tangled.org/core/appview/oauth"
 	"tangled.org/core/appview/pages"
 	"tangled.org/core/appview/reporesolver"
-	"tangled.org/core/appview/validator"
 	xrpcclient "tangled.org/core/appview/xrpcclient"
 	"tangled.org/core/eventconsumer"
 	"tangled.org/core/idresolver"
@@ -51,7 +50,6 @@ enforcer      *rbac.Enforcer
 	notifier      notify.Notifier
 	logger        *slog.Logger
 	serviceAuth   *serviceauth.ServiceAuth
-	validator     *validator.Validator
 	cfClient      *cloudflare.Client
 }
 
@@ -66,7 +64,6 @@ config *config.Config,
 	notifier notify.Notifier,
 	enforcer *rbac.Enforcer,
 	logger *slog.Logger,
-	validator *validator.Validator,
 	cfClient *cloudflare.Client,
 ) *Repo {
 	return &Repo{
@@ -80,7 +77,6 @@ db:            db,
 		notifier:      notifier,
 		enforcer:      enforcer,
 		logger:        logger,
-		validator:     validator,
 		cfClient:      cfClient,
 	}
 }
@@ -231,7 +227,7 @@ Color:     &color,
 		Multiple:  multiple,
 		Created:   time.Now(),
 	}
-	if err := rp.validator.ValidateLabelDefinition(&label); err != nil {
+	if err := label.Validate(); err != nil {
 		fail(err.Error(), err)
 		return
 	}
diff --git a/appview/repo/settings.go b/appview/repo/settings.go
--- a/appview/repo/settings.go
+++ b/appview/repo/settings.go
@@ -5,7 +5,9 @@ "context"
 	"encoding/json"
 	"fmt"
 	"net/http"
+	"net/url"
 	"path"
+	"regexp"
 	"slices"
 	"strings"
 	"time"
@@ -19,6 +21,7 @@ "tangled.org/core/appview/pages"
 	"tangled.org/core/appview/sites"
 	xrpcclient "tangled.org/core/appview/xrpcclient"
 	"tangled.org/core/orm"
+	"tangled.org/core/sets"
 	"tangled.org/core/types"
 
 	comatproto "github.com/bluesky-social/indigo/api/atproto"
@@ -591,14 +594,15 @@ website     = r.FormValue("website")
 		topicStr    = r.FormValue("topics")
 	)
 
-	err = rp.validator.ValidateURI(website)
-	if website != "" && err != nil {
-		l.Error("invalid uri", "err", err)
-		rp.pages.Notice(w, noticeId, err.Error())
-		return
+	if website != "" {
+		if err := validateURI(website); err != nil {
+			l.Error("invalid uri", "err", err)
+			rp.pages.Notice(w, noticeId, err.Error())
+			return
+		}
 	}
 
-	topics, err := rp.validator.ValidateRepoTopicStr(topicStr)
+	topics, err := parseRepoTopicStr(topicStr)
 	if err != nil {
 		l.Error("invalid topics", "err", err)
 		rp.pages.Notice(w, noticeId, err.Error())
@@ -658,3 +662,59 @@ }
 
 	rp.pages.HxRefresh(w)
 }
+
+const (
+	maxTopicLen = 50
+	maxTopics   = 20
+)
+
+var (
+	topicRE = regexp.MustCompile(`\A[a-z0-9-]+\z`)
+)
+
+// parseRepoTopicStr parses and validates whitespace-separated topic string.
+//
+// Rules:
+//   - topics are separated by whitespace
+//   - each topic may contain lowercase letters, digits, and hyphens only
+//   - each topic must be <= 50 characters long
+//   - no more than 20 topics allowed
+//   - duplicates are removed
+func parseRepoTopicStr(topicStr string) ([]string, error) {
+	topicStr = strings.TrimSpace(topicStr)
+	if topicStr == "" {
+		return nil, nil
+	}
+	parts := strings.Fields(topicStr)
+	if len(parts) > maxTopics {
+		return nil, fmt.Errorf("too many topics: %d (maximum %d)", len(parts), maxTopics)
+	}
+
+	topicSet := sets.New[string]()
+
+	for _, t := range parts {
+		if topicSet.Contains(t) {
+			continue
+		}
+		if len(t) > maxTopicLen {
+			return nil, fmt.Errorf("topic '%s' is too long (maximum %d characters)", t, maxTopics)
+		}
+		if !topicRE.MatchString(t) {
+			return nil, fmt.Errorf("topic '%s' contains invalid characters (allowed: lowercase letters, digits, hyphens)", t)
+		}
+		topicSet.Insert(t)
+	}
+	return slices.Collect(topicSet.All()), nil
+}
+
+// TODO(boltless): move this to models.Repo instead
+func validateURI(uri string) error {
+	parsed, err := url.Parse(uri)
+	if err != nil {
+		return fmt.Errorf("invalid uri format")
+	}
+	if parsed.Scheme == "" {
+		return fmt.Errorf("uri scheme missing")
+	}
+	return nil
+}
diff --git a/appview/state/router.go b/appview/state/router.go
--- a/appview/state/router.go
+++ b/appview/state/router.go
@@ -280,7 +280,6 @@ s.mentionsResolver,
 		s.db,
 		s.config,
 		s.notifier,
-		s.validator,
 		s.indexer.Issues,
 		log.SubLogger(s.logger, "issues"),
 	)
@@ -298,7 +297,6 @@ s.db,
 		s.config,
 		s.notifier,
 		s.enforcer,
-		s.validator,
 		s.indexer.Pulls,
 		log.SubLogger(s.logger, "pulls"),
 	)
@@ -317,7 +315,6 @@ s.config,
 		s.notifier,
 		s.enforcer,
 		log.SubLogger(s.logger, "repo"),
-		s.validator,
 		s.cfClient,
 	)
 	return repo.Router(mw)
@@ -343,7 +340,6 @@ ls := labels.New(
 		s.oauth,
 		s.pages,
 		s.db,
-		s.validator,
 		s.enforcer,
 		s.notifier,
 		log.SubLogger(s.logger, "labels"),
diff --git a/appview/state/state.go b/appview/state/state.go
--- a/appview/state/state.go
+++ b/appview/state/state.go
@@ -25,7 +25,6 @@ phnotify "tangled.org/core/appview/notify/posthog"
 	"tangled.org/core/appview/oauth"
 	"tangled.org/core/appview/pages"
 	"tangled.org/core/appview/reporesolver"
-	"tangled.org/core/appview/validator"
 	xrpcclient "tangled.org/core/appview/xrpcclient"
 	"tangled.org/core/consts"
 	"tangled.org/core/eventconsumer"
@@ -63,7 +62,6 @@ repoResolver     *reporesolver.RepoResolver
 	knotstream       *eventconsumer.Consumer
 	spindlestream    *eventconsumer.Consumer
 	logger           *slog.Logger
-	validator        *validator.Validator
 	cfClient         *cloudflare.Client
 }
 
@@ -102,7 +100,6 @@ oauth, err := oauth.New(config, posthog, d, enforcer, res, log.SubLogger(logger, "oauth"))
 	if err != nil {
 		return nil, fmt.Errorf("failed to start oauth handler: %w", err)
 	}
-	validator := validator.New(d, res, enforcer)
 
 	repoResolver := reporesolver.New(config, enforcer, d)
 
@@ -150,7 +147,6 @@ Enforcer:   enforcer,
 		IdResolver: res,
 		Config:     config,
 		Logger:     log.SubLogger(logger, "ingester"),
-		Validator:  validator,
 	}
 	err = jc.StartJetstream(ctx, ingester.Ingest())
 	if err != nil {
@@ -211,7 +207,6 @@ repoResolver:     repoResolver,
 		knotstream:       knotstream,
 		spindlestream:    spindlestream,
 		logger:           logger,
-		validator:        validator,
 		cfClient:         cfClient,
 	}
 
diff --git a/appview/validator/issue.go b/appview/validator/issue.go
deleted file mode 100644
--- a/appview/validator/issue.go
+++ /dev/null
@@ -1,55 +0,0 @@
-package validator
-
-import (
-	"fmt"
-	"strings"
-
-	"tangled.org/core/appview/db"
-	"tangled.org/core/appview/models"
-	"tangled.org/core/orm"
-)
-
-func (v *Validator) ValidateIssueComment(comment *models.IssueComment) error {
-	// if comments have parents, only ingest ones that are 1 level deep
-	if comment.ReplyTo != nil {
-		parents, err := db.GetIssueComments(v.db, orm.FilterEq("at_uri", *comment.ReplyTo))
-		if err != nil {
-			return fmt.Errorf("failed to fetch parent comment: %w", err)
-		}
-		if len(parents) != 1 {
-			return fmt.Errorf("incorrect number of parent comments returned: %d", len(parents))
-		}
-
-		// depth check
-		parent := parents[0]
-		if parent.ReplyTo != nil {
-			return fmt.Errorf("incorrect depth, this comment is replying at depth >1")
-		}
-	}
-
-	if sb := strings.TrimSpace(v.sanitizer.SanitizeDefault(comment.Body)); sb == "" {
-		return fmt.Errorf("body is empty after HTML sanitization")
-	}
-
-	return nil
-}
-
-func (v *Validator) ValidateIssue(issue *models.Issue) error {
-	if issue.Title == "" {
-		return fmt.Errorf("issue title is empty")
-	}
-
-	if issue.Body == "" {
-		return fmt.Errorf("issue body is empty")
-	}
-
-	if st := strings.TrimSpace(v.sanitizer.SanitizeDescription(issue.Title)); st == "" {
-		return fmt.Errorf("title is empty after HTML sanitization")
-	}
-
-	if sb := strings.TrimSpace(v.sanitizer.SanitizeDefault(issue.Body)); sb == "" {
-		return fmt.Errorf("body is empty after HTML sanitization")
-	}
-
-	return nil
-}
diff --git a/appview/validator/label.go b/appview/validator/label.go
deleted file mode 100644
--- a/appview/validator/label.go
+++ /dev/null
@@ -1,217 +0,0 @@
-package validator
-
-import (
-	"context"
-	"fmt"
-	"regexp"
-	"slices"
-	"strings"
-
-	"github.com/bluesky-social/indigo/atproto/syntax"
-	"tangled.org/core/api/tangled"
-	"tangled.org/core/appview/models"
-)
-
-var (
-	// Label name should be alphanumeric with hyphens/underscores, but not start/end with them
-	labelNameRegex = regexp.MustCompile(`^[a-zA-Z0-9]([a-zA-Z0-9_-]*[a-zA-Z0-9])?$`)
-	// Color should be a valid hex color
-	colorRegex = regexp.MustCompile(`^#[a-fA-F0-9]{6}$`)
-	// You can only label issues and pulls presently
-	validScopes = []string{tangled.RepoIssueNSID, tangled.RepoPullNSID}
-)
-
-func (v *Validator) ValidateLabelDefinition(label *models.LabelDefinition) error {
-	if label.Name == "" {
-		return fmt.Errorf("label name is empty")
-	}
-	if len(label.Name) > 40 {
-		return fmt.Errorf("label name too long (max 40 graphemes)")
-	}
-	if len(label.Name) < 1 {
-		return fmt.Errorf("label name too short (min 1 grapheme)")
-	}
-	if !labelNameRegex.MatchString(label.Name) {
-		return fmt.Errorf("label name contains invalid characters (use only letters, numbers, hyphens, and underscores)")
-	}
-
-	if !label.ValueType.IsConcreteType() {
-		return fmt.Errorf("invalid value type: %q (must be one of: null, boolean, integer, string)", label.ValueType.Type)
-	}
-
-	// null type checks: cannot be enums, multiple or explicit format
-	if label.ValueType.IsNull() && label.ValueType.IsEnum() {
-		return fmt.Errorf("null type cannot be used in conjunction with enum type")
-	}
-	if label.ValueType.IsNull() && label.Multiple {
-		return fmt.Errorf("null type labels cannot be multiple")
-	}
-	if label.ValueType.IsNull() && !label.ValueType.IsAnyFormat() {
-		return fmt.Errorf("format cannot be used in conjunction with null type")
-	}
-
-	// format checks: cannot be used with enum, or integers
-	if !label.ValueType.IsAnyFormat() && label.ValueType.IsEnum() {
-		return fmt.Errorf("enum types cannot be used in conjunction with format specification")
-	}
-
-	if !label.ValueType.IsAnyFormat() && !label.ValueType.IsString() {
-		return fmt.Errorf("format specifications are only permitted on string types")
-	}
-
-	// validate scope (nsid format)
-	if label.Scope == nil {
-		return fmt.Errorf("scope is required")
-	}
-	for _, s := range label.Scope {
-		if _, err := syntax.ParseNSID(s); err != nil {
-			return fmt.Errorf("failed to parse scope: %w", err)
-		}
-		if !slices.Contains(validScopes, s) {
-			return fmt.Errorf("invalid scope: scope must be present in %q", validScopes)
-		}
-	}
-
-	// validate color if provided
-	if label.Color != nil {
-		color := strings.TrimSpace(*label.Color)
-		if color == "" {
-			// empty color is fine, set to nil
-			label.Color = nil
-		} else {
-			if !colorRegex.MatchString(color) {
-				return fmt.Errorf("color must be a valid hex color (e.g. #79FFE1 or #000)")
-			}
-			// expand 3-digit hex to 6-digit hex
-			if len(color) == 4 { // #ABC
-				color = fmt.Sprintf("#%c%c%c%c%c%c", color[1], color[1], color[2], color[2], color[3], color[3])
-			}
-			// convert to uppercase for consistency
-			color = strings.ToUpper(color)
-			label.Color = &color
-		}
-	}
-
-	return nil
-}
-
-func (v *Validator) ValidateLabelOp(labelDef *models.LabelDefinition, repo *models.Repo, labelOp *models.LabelOp) error {
-	if labelDef == nil {
-		return fmt.Errorf("label definition is required")
-	}
-	if repo == nil {
-		return fmt.Errorf("repo is required")
-	}
-	if labelOp == nil {
-		return fmt.Errorf("label operation is required")
-	}
-
-	// validate permissions: only collaborators can apply labels currently
-	//
-	// TODO: introduce a repo:triage permission
-	ok, err := v.enforcer.IsPushAllowed(labelOp.Did, repo.Knot, repo.DidSlashRepo())
-	if err != nil {
-		return fmt.Errorf("failed to enforce permissions: %w", err)
-	}
-	if !ok {
-		return fmt.Errorf("unauhtorized label operation")
-	}
-
-	expectedKey := labelDef.AtUri().String()
-	if labelOp.OperandKey != expectedKey {
-		return fmt.Errorf("operand key %q does not match label definition URI %q", labelOp.OperandKey, expectedKey)
-	}
-
-	if labelOp.Operation != models.LabelOperationAdd && labelOp.Operation != models.LabelOperationDel {
-		return fmt.Errorf("invalid operation: %q (must be 'add' or 'del')", labelOp.Operation)
-	}
-
-	if labelOp.Subject == "" {
-		return fmt.Errorf("subject URI is required")
-	}
-	if _, err := syntax.ParseATURI(string(labelOp.Subject)); err != nil {
-		return fmt.Errorf("invalid subject URI: %w", err)
-	}
-
-	if err := v.validateOperandValue(labelDef, labelOp); err != nil {
-		return fmt.Errorf("invalid operand value: %w", err)
-	}
-
-	// Validate performed time is not zero/invalid
-	if labelOp.PerformedAt.IsZero() {
-		return fmt.Errorf("performed_at timestamp is required")
-	}
-
-	return nil
-}
-
-func (v *Validator) validateOperandValue(labelDef *models.LabelDefinition, labelOp *models.LabelOp) error {
-	valueType := labelDef.ValueType
-
-	// this is permitted, it "unsets" a label
-	if labelOp.OperandValue == "" {
-		labelOp.Operation = models.LabelOperationDel
-		return nil
-	}
-
-	switch valueType.Type {
-	case models.ConcreteTypeNull:
-		// For null type, value should be empty
-		if labelOp.OperandValue != "null" {
-			return fmt.Errorf("null type requires empty value, got %q", labelOp.OperandValue)
-		}
-
-	case models.ConcreteTypeString:
-		// For string type, validate enum constraints if present
-		if valueType.IsEnum() {
-			if !slices.Contains(valueType.Enum, labelOp.OperandValue) {
-				return fmt.Errorf("value %q is not in allowed enum values %v", labelOp.OperandValue, valueType.Enum)
-			}
-		}
-
-		switch valueType.Format {
-		case models.ValueTypeFormatDid:
-			id, err := v.resolver.ResolveIdent(context.Background(), labelOp.OperandValue)
-			if err != nil {
-				return fmt.Errorf("failed to resolve did/handle: %w", err)
-			}
-
-			labelOp.OperandValue = id.DID.String()
-
-		case models.ValueTypeFormatAny, "":
-		default:
-			return fmt.Errorf("unsupported format constraint: %q", valueType.Format)
-		}
-
-	case models.ConcreteTypeInt:
-		if labelOp.OperandValue == "" {
-			return fmt.Errorf("integer type requires non-empty value")
-		}
-		if _, err := fmt.Sscanf(labelOp.OperandValue, "%d", new(int)); err != nil {
-			return fmt.Errorf("value %q is not a valid integer", labelOp.OperandValue)
-		}
-
-		if valueType.IsEnum() {
-			if !slices.Contains(valueType.Enum, labelOp.OperandValue) {
-				return fmt.Errorf("value %q is not in allowed enum values %v", labelOp.OperandValue, valueType.Enum)
-			}
-		}
-
-	case models.ConcreteTypeBool:
-		if labelOp.OperandValue != "true" && labelOp.OperandValue != "false" {
-			return fmt.Errorf("boolean type requires value to be 'true' or 'false', got %q", labelOp.OperandValue)
-		}
-
-		// validate enum constraints if present (though uncommon for booleans)
-		if valueType.IsEnum() {
-			if !slices.Contains(valueType.Enum, labelOp.OperandValue) {
-				return fmt.Errorf("value %q is not in allowed enum values %v", labelOp.OperandValue, valueType.Enum)
-			}
-		}
-
-	default:
-		return fmt.Errorf("unsupported value type: %q", valueType.Type)
-	}
-
-	return nil
-}
diff --git a/appview/validator/patch.go b/appview/validator/patch.go
deleted file mode 100644
--- a/appview/validator/patch.go
+++ /dev/null
@@ -1,25 +0,0 @@
-package validator
-
-import (
-	"fmt"
-	"strings"
-
-	"tangled.org/core/patchutil"
-)
-
-func (v *Validator) ValidatePatch(patch *string) error {
-	if patch == nil || *patch == "" {
-		return fmt.Errorf("patch is empty")
-	}
-
-	// add newline if not present to diff style patches
-	if !patchutil.IsFormatPatch(*patch) && !strings.HasSuffix(*patch, "\n") {
-		*patch = *patch + "\n"
-	}
-
-	if err := patchutil.IsPatchValid(*patch); err != nil {
-		return err
-	}
-
-	return nil
-}
diff --git a/appview/validator/repo_topics.go b/appview/validator/repo_topics.go
deleted file mode 100644
--- a/appview/validator/repo_topics.go
+++ /dev/null
@@ -1,53 +0,0 @@
-package validator
-
-import (
-	"fmt"
-	"maps"
-	"regexp"
-	"slices"
-	"strings"
-)
-
-const (
-	maxTopicLen = 50
-	maxTopics   = 20
-)
-
-var (
-	topicRE = regexp.MustCompile(`\A[a-z0-9-]+\z`)
-)
-
-// ValidateRepoTopicStr parses and validates whitespace-separated topic string.
-//
-// Rules:
-//   - topics are separated by whitespace
-//   - each topic may contain lowercase letters, digits, and hyphens only
-//   - each topic must be <= 50 characters long
-//   - no more than 20 topics allowed
-//   - duplicates are removed
-func (v *Validator) ValidateRepoTopicStr(topicsStr string) ([]string, error) {
-	topicsStr = strings.TrimSpace(topicsStr)
-	if topicsStr == "" {
-		return nil, nil
-	}
-	parts := strings.Fields(topicsStr)
-	if len(parts) > maxTopics {
-		return nil, fmt.Errorf("too many topics: %d (maximum %d)", len(parts), maxTopics)
-	}
-
-	topicSet := make(map[string]struct{})
-
-	for _, t := range parts {
-		if _, exists := topicSet[t]; exists {
-			continue
-		}
-		if len(t) > maxTopicLen {
-			return nil, fmt.Errorf("topic '%s' is too long (maximum %d characters)", t, maxTopics)
-		}
-		if !topicRE.MatchString(t) {
-			return nil, fmt.Errorf("topic '%s' contains invalid characters (allowed: lowercase letters, digits, hyphens)", t)
-		}
-		topicSet[t] = struct{}{}
-	}
-	return slices.Collect(maps.Keys(topicSet)), nil
-}
diff --git a/appview/validator/string.go b/appview/validator/string.go
deleted file mode 100644
--- a/appview/validator/string.go
+++ /dev/null
@@ -1,27 +0,0 @@
-package validator
-
-import (
-	"errors"
-	"fmt"
-	"unicode/utf8"
-
-	"tangled.org/core/appview/models"
-)
-
-func (v *Validator) ValidateString(s *models.String) error {
-	var err error
-
-	if utf8.RuneCountInString(s.Filename) > 140 {
-		err = errors.Join(err, fmt.Errorf("filename too long"))
-	}
-
-	if utf8.RuneCountInString(s.Description) > 280 {
-		err = errors.Join(err, fmt.Errorf("description too long"))
-	}
-
-	if len(s.Contents) == 0 {
-		err = errors.Join(err, fmt.Errorf("contents is empty"))
-	}
-
-	return err
-}
diff --git a/appview/validator/uri.go b/appview/validator/uri.go
deleted file mode 100644
--- a/appview/validator/uri.go
+++ /dev/null
@@ -1,17 +0,0 @@
-package validator
-
-import (
-	"fmt"
-	"net/url"
-)
-
-func (v *Validator) ValidateURI(uri string) error {
-	parsed, err := url.Parse(uri)
-	if err != nil {
-		return fmt.Errorf("invalid uri format")
-	}
-	if parsed.Scheme == "" {
-		return fmt.Errorf("uri scheme missing")
-	}
-	return nil
-}
diff --git a/appview/validator/validator.go b/appview/validator/validator.go
deleted file mode 100644
--- a/appview/validator/validator.go
+++ /dev/null
@@ -1,24 +0,0 @@
-package validator
-
-import (
-	"tangled.org/core/appview/db"
-	"tangled.org/core/appview/pages/markup"
-	"tangled.org/core/idresolver"
-	"tangled.org/core/rbac"
-)
-
-type Validator struct {
-	db        *db.DB
-	sanitizer markup.Sanitizer
-	resolver  *idresolver.Resolver
-	enforcer  *rbac.Enforcer
-}
-
-func New(db *db.DB, res *idresolver.Resolver, enforcer *rbac.Enforcer) *Validator {
-	return &Validator{
-		db:        db,
-		sanitizer: markup.NewSanitizer(),
-		resolver:  res,
-		enforcer:  enforcer,
-	}
-}