diff --git a/internal/db/postgres/comment_repo.go b/internal/db/postgres/comment_repo.go
new file mode 100644
index 0000000..df95204
--- /dev/null
+++ b/internal/db/postgres/comment_repo.go
@@ -0,0 +1,354 @@
+package postgres
+
+import (
+	"Coves/internal/core/comments"
+	"context"
+	"database/sql"
+	"fmt"
+	"log"
+	"strings"
+
+	"github.com/lib/pq"
+)
+
+type postgresCommentRepo struct {
+	db *sql.DB
+}
+
+// NewCommentRepository creates a new PostgreSQL comment repository
+func NewCommentRepository(db *sql.DB) comments.Repository {
+	return &postgresCommentRepo{db: db}
+}
+
+// Create inserts a new comment into the comments table
+// Called by Jetstream consumer after comment is created on PDS
+// Idempotent: Returns success if comment already exists (for Jetstream replays)
+func (r *postgresCommentRepo) Create(ctx context.Context, comment *comments.Comment) error {
+	query := `
+		INSERT INTO comments (
+			uri, cid, rkey, commenter_did,
+			root_uri, root_cid, parent_uri, parent_cid,
+			content, content_facets, embed, content_labels, langs,
+			created_at, indexed_at
+		) VALUES (
+			$1, $2, $3, $4,
+			$5, $6, $7, $8,
+			$9, $10, $11, $12, $13,
+			$14, NOW()
+		)
+		ON CONFLICT (uri) DO NOTHING
+		RETURNING id, indexed_at
+	`
+
+	err := r.db.QueryRowContext(
+		ctx, query,
+		comment.URI, comment.CID, comment.RKey, comment.CommenterDID,
+		comment.RootURI, comment.RootCID, comment.ParentURI, comment.ParentCID,
+		comment.Content, comment.ContentFacets, comment.Embed, comment.ContentLabels, pq.Array(comment.Langs),
+		comment.CreatedAt,
+	).Scan(&comment.ID, &comment.IndexedAt)
+
+	// ON CONFLICT DO NOTHING returns no rows if duplicate - this is OK (idempotent)
+	if err == sql.ErrNoRows {
+		return nil // Comment already exists, no error for idempotency
+	}
+
+	if err != nil {
+		// Check for unique constraint violation
+		if strings.Contains(err.Error(), "duplicate key") {
+			return comments.ErrCommentAlreadyExists
+		}
+
+		return fmt.Errorf("failed to insert comment: %w", err)
+	}
+
+	return nil
+}
+
+// Update modifies an existing comment's content fields
+// Called by Jetstream consumer after comment is updated on PDS
+// Preserves vote counts and created_at timestamp
+func (r *postgresCommentRepo) Update(ctx context.Context, comment *comments.Comment) error {
+	query := `
+		UPDATE comments
+		SET
+			cid = $1,
+			content = $2,
+			content_facets = $3,
+			embed = $4,
+			content_labels = $5,
+			langs = $6
+		WHERE uri = $7 AND deleted_at IS NULL
+		RETURNING id, indexed_at, created_at, upvote_count, downvote_count, score, reply_count
+	`
+
+	err := r.db.QueryRowContext(
+		ctx, query,
+		comment.CID,
+		comment.Content,
+		comment.ContentFacets,
+		comment.Embed,
+		comment.ContentLabels,
+		pq.Array(comment.Langs),
+		comment.URI,
+	).Scan(
+		&comment.ID,
+		&comment.IndexedAt,
+		&comment.CreatedAt,
+		&comment.UpvoteCount,
+		&comment.DownvoteCount,
+		&comment.Score,
+		&comment.ReplyCount,
+	)
+
+	if err == sql.ErrNoRows {
+		return comments.ErrCommentNotFound
+	}
+	if err != nil {
+		return fmt.Errorf("failed to update comment: %w", err)
+	}
+
+	return nil
+}
+
+// GetByURI retrieves a comment by its AT-URI
+// Used by Jetstream consumer for UPDATE/DELETE operations
+func (r *postgresCommentRepo) GetByURI(ctx context.Context, uri string) (*comments.Comment, error) {
+	query := `
+		SELECT
+			id, uri, cid, rkey, commenter_did,
+			root_uri, root_cid, parent_uri, parent_cid,
+			content, content_facets, embed, content_labels, langs,
+			created_at, indexed_at, deleted_at,
+			upvote_count, downvote_count, score, reply_count
+		FROM comments
+		WHERE uri = $1
+	`
+
+	var comment comments.Comment
+	var langs pq.StringArray
+
+	err := r.db.QueryRowContext(ctx, query, uri).Scan(
+		&comment.ID, &comment.URI, &comment.CID, &comment.RKey, &comment.CommenterDID,
+		&comment.RootURI, &comment.RootCID, &comment.ParentURI, &comment.ParentCID,
+		&comment.Content, &comment.ContentFacets, &comment.Embed, &comment.ContentLabels, &langs,
+		&comment.CreatedAt, &comment.IndexedAt, &comment.DeletedAt,
+		&comment.UpvoteCount, &comment.DownvoteCount, &comment.Score, &comment.ReplyCount,
+	)
+
+	if err == sql.ErrNoRows {
+		return nil, comments.ErrCommentNotFound
+	}
+	if err != nil {
+		return nil, fmt.Errorf("failed to get comment by URI: %w", err)
+	}
+
+	comment.Langs = langs
+
+	return &comment, nil
+}
+
+// Delete soft-deletes a comment (sets deleted_at)
+// Called by Jetstream consumer after comment is deleted from PDS
+// Idempotent: Returns success if comment already deleted
+func (r *postgresCommentRepo) Delete(ctx context.Context, uri string) error {
+	query := `
+		UPDATE comments
+		SET deleted_at = NOW()
+		WHERE uri = $1 AND deleted_at IS NULL
+	`
+
+	result, err := r.db.ExecContext(ctx, query, uri)
+	if err != nil {
+		return fmt.Errorf("failed to delete comment: %w", err)
+	}
+
+	rowsAffected, err := result.RowsAffected()
+	if err != nil {
+		return fmt.Errorf("failed to check delete result: %w", err)
+	}
+
+	// Idempotent: If no rows affected, comment already deleted (OK for Jetstream replays)
+	if rowsAffected == 0 {
+		return nil
+	}
+
+	return nil
+}
+
+// ListByRoot retrieves all active comments in a thread (flat)
+// Used for fetching entire comment threads on posts
+func (r *postgresCommentRepo) ListByRoot(ctx context.Context, rootURI string, limit, offset int) ([]*comments.Comment, error) {
+	query := `
+		SELECT
+			id, uri, cid, rkey, commenter_did,
+			root_uri, root_cid, parent_uri, parent_cid,
+			content, content_facets, embed, content_labels, langs,
+			created_at, indexed_at, deleted_at,
+			upvote_count, downvote_count, score, reply_count
+		FROM comments
+		WHERE root_uri = $1 AND deleted_at IS NULL
+		ORDER BY created_at ASC
+		LIMIT $2 OFFSET $3
+	`
+
+	rows, err := r.db.QueryContext(ctx, query, rootURI, limit, offset)
+	if err != nil {
+		return nil, fmt.Errorf("failed to list comments by root: %w", err)
+	}
+	defer func() {
+		if err := rows.Close(); err != nil {
+			log.Printf("Failed to close rows: %v", err)
+		}
+	}()
+
+	var result []*comments.Comment
+	for rows.Next() {
+		var comment comments.Comment
+		var langs pq.StringArray
+
+		err := rows.Scan(
+			&comment.ID, &comment.URI, &comment.CID, &comment.RKey, &comment.CommenterDID,
+			&comment.RootURI, &comment.RootCID, &comment.ParentURI, &comment.ParentCID,
+			&comment.Content, &comment.ContentFacets, &comment.Embed, &comment.ContentLabels, &langs,
+			&comment.CreatedAt, &comment.IndexedAt, &comment.DeletedAt,
+			&comment.UpvoteCount, &comment.DownvoteCount, &comment.Score, &comment.ReplyCount,
+		)
+		if err != nil {
+			return nil, fmt.Errorf("failed to scan comment: %w", err)
+		}
+
+		comment.Langs = langs
+		result = append(result, &comment)
+	}
+
+	if err = rows.Err(); err != nil {
+		return nil, fmt.Errorf("error iterating comments: %w", err)
+	}
+
+	return result, nil
+}
+
+// ListByParent retrieves direct replies to a post or comment
+// Used for building nested/threaded comment views
+func (r *postgresCommentRepo) ListByParent(ctx context.Context, parentURI string, limit, offset int) ([]*comments.Comment, error) {
+	query := `
+		SELECT
+			id, uri, cid, rkey, commenter_did,
+			root_uri, root_cid, parent_uri, parent_cid,
+			content, content_facets, embed, content_labels, langs,
+			created_at, indexed_at, deleted_at,
+			upvote_count, downvote_count, score, reply_count
+		FROM comments
+		WHERE parent_uri = $1 AND deleted_at IS NULL
+		ORDER BY created_at ASC
+		LIMIT $2 OFFSET $3
+	`
+
+	rows, err := r.db.QueryContext(ctx, query, parentURI, limit, offset)
+	if err != nil {
+		return nil, fmt.Errorf("failed to list comments by parent: %w", err)
+	}
+	defer func() {
+		if err := rows.Close(); err != nil {
+			log.Printf("Failed to close rows: %v", err)
+		}
+	}()
+
+	var result []*comments.Comment
+	for rows.Next() {
+		var comment comments.Comment
+		var langs pq.StringArray
+
+		err := rows.Scan(
+			&comment.ID, &comment.URI, &comment.CID, &comment.RKey, &comment.CommenterDID,
+			&comment.RootURI, &comment.RootCID, &comment.ParentURI, &comment.ParentCID,
+			&comment.Content, &comment.ContentFacets, &comment.Embed, &comment.ContentLabels, &langs,
+			&comment.CreatedAt, &comment.IndexedAt, &comment.DeletedAt,
+			&comment.UpvoteCount, &comment.DownvoteCount, &comment.Score, &comment.ReplyCount,
+		)
+		if err != nil {
+			return nil, fmt.Errorf("failed to scan comment: %w", err)
+		}
+
+		comment.Langs = langs
+		result = append(result, &comment)
+	}
+
+	if err = rows.Err(); err != nil {
+		return nil, fmt.Errorf("error iterating comments: %w", err)
+	}
+
+	return result, nil
+}
+
+// CountByParent counts direct replies to a post or comment
+// Used for showing reply counts in threading UI
+func (r *postgresCommentRepo) CountByParent(ctx context.Context, parentURI string) (int, error) {
+	query := `
+		SELECT COUNT(*)
+		FROM comments
+		WHERE parent_uri = $1 AND deleted_at IS NULL
+	`
+
+	var count int
+	err := r.db.QueryRowContext(ctx, query, parentURI).Scan(&count)
+	if err != nil {
+		return 0, fmt.Errorf("failed to count comments by parent: %w", err)
+	}
+
+	return count, nil
+}
+
+// ListByCommenter retrieves all active comments by a specific user
+// Future: Used for user comment history
+func (r *postgresCommentRepo) ListByCommenter(ctx context.Context, commenterDID string, limit, offset int) ([]*comments.Comment, error) {
+	query := `
+		SELECT
+			id, uri, cid, rkey, commenter_did,
+			root_uri, root_cid, parent_uri, parent_cid,
+			content, content_facets, embed, content_labels, langs,
+			created_at, indexed_at, deleted_at,
+			upvote_count, downvote_count, score, reply_count
+		FROM comments
+		WHERE commenter_did = $1 AND deleted_at IS NULL
+		ORDER BY created_at DESC
+		LIMIT $2 OFFSET $3
+	`
+
+	rows, err := r.db.QueryContext(ctx, query, commenterDID, limit, offset)
+	if err != nil {
+		return nil, fmt.Errorf("failed to list comments by commenter: %w", err)
+	}
+	defer func() {
+		if err := rows.Close(); err != nil {
+			log.Printf("Failed to close rows: %v", err)
+		}
+	}()
+
+	var result []*comments.Comment
+	for rows.Next() {
+		var comment comments.Comment
+		var langs pq.StringArray
+
+		err := rows.Scan(
+			&comment.ID, &comment.URI, &comment.CID, &comment.RKey, &comment.CommenterDID,
+			&comment.RootURI, &comment.RootCID, &comment.ParentURI, &comment.ParentCID,
+			&comment.Content, &comment.ContentFacets, &comment.Embed, &comment.ContentLabels, &langs,
+			&comment.CreatedAt, &comment.IndexedAt, &comment.DeletedAt,
+			&comment.UpvoteCount, &comment.DownvoteCount, &comment.Score, &comment.ReplyCount,
+		)
+		if err != nil {
+			return nil, fmt.Errorf("failed to scan comment: %w", err)
+		}
+
+		comment.Langs = langs
+		result = append(result, &comment)
+	}
+
+	if err = rows.Err(); err != nil {
+		return nil, fmt.Errorf("error iterating comments: %w", err)
+	}
+
+	return result, nil
+}