diff --git a/ql/Cargo.lock b/ql/Cargo.lock
index 8a6de476fd9..27e5cc4ebdc 100644
Binary files a/ql/Cargo.lock and b/ql/Cargo.lock differ
diff --git a/ql/extractor/Cargo.toml b/ql/extractor/Cargo.toml
index 440b9434d34..2387c38ac4f 100644
--- a/ql/extractor/Cargo.toml
+++ b/ql/extractor/Cargo.toml
@@ -10,7 +10,6 @@ edition = "2018"
 tree-sitter = ">= 0.20, < 0.21"
 tree-sitter-ql = { git = "https://github.com/tree-sitter/tree-sitter-ql.git", rev = "d08db734f8dc52f6bc04db53a966603122bc6985"}
 tree-sitter-ql-dbscheme = { git = "https://github.com/erik-krogh/tree-sitter-ql-dbscheme.git", rev = "63e1344353f63931e88bfbc2faa2e78e1421b213"}
-tree-sitter-ql-yaml = {git = "https://github.com/erik-krogh/tree-sitter-ql.git", rev = "cf704bf3671e1ae148e173464fb65a4d2bbf5f99"}
 tree-sitter-blame = {path = "../buramu/tree-sitter-blame"}
 tree-sitter-json = {git = "https://github.com/tausbn/tree-sitter-json.git", rev = "745663ee997f1576fe1e7187e6347e0db36ec7a9"}
 clap = { version = "4.2", features = ["derive"] }
diff --git a/ql/extractor/src/autobuilder.rs b/ql/extractor/src/autobuilder.rs
index ce58a217d8c..9a89cf01b8d 100644
--- a/ql/extractor/src/autobuilder.rs
+++ b/ql/extractor/src/autobuilder.rs
@@ -15,7 +15,7 @@ pub fn run(_: Options) -> std::io::Result<()> {
 
     autobuilder::Autobuilder::new("ql", PathBuf::from(database))
         .include_extensions(&[".ql", ".qll", ".dbscheme", ".json", ".jsonc", ".jsonl"])
-        .include_globs(&["**/qlpack.yml", "deprecated.blame"])
+        .include_globs(&["deprecated.blame"])
         .size_limit("10m")
         .run()
 }
diff --git a/ql/extractor/src/extractor.rs b/ql/extractor/src/extractor.rs
index 6728f5ae877..fddacf229f4 100644
--- a/ql/extractor/src/extractor.rs
+++ b/ql/extractor/src/extractor.rs
@@ -42,12 +42,6 @@ pub fn run(options: Options) -> std::io::Result<()> {
                 node_types: tree_sitter_ql_dbscheme::NODE_TYPES,
                 file_extensions: vec!["dbscheme".into()],
             },
-            simple::LanguageSpec {
-                prefix: "yaml",
-                ts_language: tree_sitter_ql_yaml::language(),
-                node_types: tree_sitter_ql_yaml::NODE_TYPES,
-                file_extensions: vec!["yml".into()],
-            },
             simple::LanguageSpec {
                 prefix: "json",
                 ts_language: tree_sitter_json::language(),
diff --git a/ql/extractor/src/generator.rs b/ql/extractor/src/generator.rs
index cdfdd17df4d..ce5fcf1b12c 100644
--- a/ql/extractor/src/generator.rs
+++ b/ql/extractor/src/generator.rs
@@ -31,10 +31,6 @@ pub fn run(options: Options) -> std::io::Result<()> {
             name: "Dbscheme".to_owned(),
             node_types: tree_sitter_ql_dbscheme::NODE_TYPES,
         },
-        Language {
-            name: "Yaml".to_owned(),
-            node_types: tree_sitter_ql_yaml::NODE_TYPES,
-        },
         Language {
             name: "Blame".to_owned(),
             node_types: tree_sitter_blame::NODE_TYPES,
diff --git a/ql/ql/src/codeql_ql/ast/Ast.qll b/ql/ql/src/codeql_ql/ast/Ast.qll
index 630b07bd680..616438da756 100644
--- a/ql/ql/src/codeql_ql/ast/Ast.qll
+++ b/ql/ql/src/codeql_ql/ast/Ast.qll
@@ -38,8 +38,6 @@ class AstNode extends TAstNode {
       result = node.getLocation()
     )
     or
-    result = toGenerateYaml(this).getLocation()
-    or
     result = toDbscheme(this).getLocation()
   }
 
@@ -2573,126 +2571,49 @@ class BindingSet extends Annotation {
  * Classes modeling YAML AST nodes.
  */
 module YAML {
-  /** A node in a YAML file */
-  class YamlNode extends TYamlNode, AstNode {
-    /** Holds if the predicate is a root node (has no parent) */
-    predicate isRoot() { not exists(this.getParent()) }
+  private import codeql.yaml.Yaml as LibYaml
 
-    override AstNode getParent() { toGenerateYaml(result) = toGenerateYaml(this).getParent() }
-  }
+  private module YamlSig implements LibYaml::InputSig {
+    import codeql.Locations
 
-  /** DEPRECATED: Alias for YamlNode */
-  deprecated class YAMLNode = YamlNode;
+    class LocatableBase extends @yaml_locatable {
+      Location getLocation() { yaml_locations(this, result) }
 
-  /** A YAML comment. */
-  class YamlComment extends TYamlComment, YamlNode {
-    Yaml::Comment yamlcomment;
-
-    YamlComment() { this = TYamlComment(yamlcomment) }
-
-    override string getAPrimaryQlClass() { result = "YamlComment" }
-  }
-
-  /** DEPRECATED: Alias for YamlComment */
-  deprecated class YAMLComment = YamlComment;
-
-  /** A YAML entry. */
-  class YamlEntry extends TYamlEntry, YamlNode {
-    Yaml::Entry yamle;
-
-    YamlEntry() { this = TYamlEntry(yamle) }
-
-    /** Gets the key of this YAML entry. */
-    YamlKey getKey() {
-      exists(Yaml::Keyvaluepair pair |
-        pair.getParent() = yamle and
-        result = TYamlKey(pair.getKey())
-      )
+      string toString() { none() }
     }
 
-    YamlListItem getListItem() { toGenerateYaml(result).getParent() = yamle }
+    class NodeBase extends LocatableBase, @yaml_node {
+      NodeBase getChildNode(int i) { yaml(result, _, this, i, _, _) }
 
-    /** Gets the value of this YAML entry. */
-    YamlValue getValue() {
-      exists(Yaml::Keyvaluepair pair |
-        pair.getParent() = yamle and
-        result = TYamlValue(pair.getValue())
-      )
+      string getTag() { yaml(this, _, _, _, result, _) }
+
+      string getAnchor() { yaml_anchors(this, result) }
+
+      override string toString() { yaml(this, _, _, _, _, result) }
     }
 
-    override string getAPrimaryQlClass() { result = "YamlEntry" }
-  }
+    class ScalarNodeBase extends NodeBase, @yaml_scalar_node {
+      int getStyle() { yaml_scalars(this, result, _) }
 
-  /** DEPRECATED: Alias for YamlEntry */
-  deprecated class YAMLEntry = YamlEntry;
-
-  /** A YAML key. */
-  class YamlKey extends TYamlKey, YamlNode {
-    Yaml::Key yamlkey;
-
-    YamlKey() { this = TYamlKey(yamlkey) }
-
-    /**
-     * Gets the value of this YAML key.
-     */
-    YamlValue getValue() {
-      exists(Yaml::Keyvaluepair pair |
-        pair.getKey() = yamlkey and result = TYamlValue(pair.getValue())
-      )
+      string getValue() { yaml_scalars(this, _, result) }
     }
 
-    override string getAPrimaryQlClass() { result = "YamlKey" }
+    class CollectionNodeBase extends NodeBase, @yaml_collection_node { }
 
-    /** Gets the value of this YAML value. */
-    string getNamePart(int i) {
-      i = 0 and result = yamlkey.getChild(0).(Yaml::SimpleId).getValue()
-      or
-      exists(YamlKey child |
-        child = TYamlKey(yamlkey.getChild(1)) and
-        result = child.getNamePart(i - 1)
-      )
+    class MappingNodeBase extends CollectionNodeBase, @yaml_mapping_node { }
+
+    class SequenceNodeBase extends CollectionNodeBase, @yaml_sequence_node { }
+
+    class AliasNodeBase extends NodeBase, @yaml_alias_node {
+      string getTarget() { yaml_aliases(this, result) }
     }
 
-    /**
-     * Gets all the name parts of this YAML key concatenated with `/`.
-     * Dashes are replaced with `/` (because we don't have that information in the generated AST).
-     */
-    string getQualifiedName() {
-      result = concat(string part, int i | part = this.getNamePart(i) | part, "/" order by i)
+    class ParseErrorBase extends LocatableBase, @yaml_error {
+      string getMessage() { yaml_errors(this, result) }
     }
   }
 
-  /** DEPRECATED: Alias for YamlKey */
-  deprecated class YAMLKey = YamlKey;
-
-  /** A YAML list item. */
-  class YamlListItem extends TYamlListitem, YamlNode {
-    Yaml::Listitem yamllistitem;
-
-    YamlListItem() { this = TYamlListitem(yamllistitem) }
-
-    /**
-     * Gets the value of this YAML list item.
-     */
-    YamlValue getValue() { result = TYamlValue(yamllistitem.getChild()) }
-
-    override string getAPrimaryQlClass() { result = "YamlListItem" }
-  }
-
-  /** DEPRECATED: Alias for YamlListItem */
-  deprecated class YAMLListItem = YamlListItem;
-
-  /** A YAML value. */
-  class YamlValue extends TYamlValue, YamlNode {
-    Yaml::Value yamlvalue;
-
-    YamlValue() { this = TYamlValue(yamlvalue) }
-
-    override string getAPrimaryQlClass() { result = "YamlValue" }
-
-    /** Gets the value of this YAML value. */
-    string getValue() { result = yamlvalue.getValue() }
-  }
+  import LibYaml::Make<YamlSig>
 
   // to not expose the entire `File` API on `QlPack`.
   private newtype TQLPack = MKQlPack(File file) { file.getBaseName() = "qlpack.yml" }
@@ -2705,15 +2626,16 @@ module YAML {
 
     QLPack() { this = MKQlPack(file) }
 
-    private string getProperty(string name) {
-      exists(YamlEntry entry |
-        entry.isRoot() and
-        entry.getKey().getQualifiedName() = name and
-        result = entry.getValue().getValue().trim() and
-        entry.getLocation().getFile() = file
+    private YamlValue get(string name) {
+      exists(YamlMapping m |
+        m instanceof YamlDocument and
+        m.getFile() = file and
+        result = m.lookup(name)
       )
     }
 
+    private string getProperty(string name) { result = this.get(name).(YamlScalar).getValue() }
+
     /** Gets the name of this qlpack */
     string getName() { result = this.getProperty("name") }
 
@@ -2728,32 +2650,12 @@ module YAML {
     /** Gets the file that this `QLPack` represents. */
     File getFile() { result = file }
 
-    private predicate isADependency(YamlEntry entry) {
-      exists(YamlEntry deps |
-        deps.getLocation().getFile() = file and entry.getLocation().getFile() = file
-      |
-        deps.isRoot() and
-        deps.getKey().getQualifiedName() = ["dependencies", "libraryPathDependencies"] and
-        entry.getLocation().getStartLine() = 1 + deps.getLocation().getStartLine() and
-        entry.getLocation().getStartColumn() > deps.getLocation().getStartColumn()
-      )
-      or
-      exists(YamlEntry prev | this.isADependency(prev) |
-        prev.getLocation().getFile() = file and
-        entry.getLocation().getFile() = file and
-        entry.getLocation().getStartLine() = 1 + prev.getLocation().getStartLine() and
-        entry.getLocation().getStartColumn() = prev.getLocation().getStartColumn()
-      )
-    }
-
     predicate hasDependency(string name, string version) {
-      exists(YamlEntry entry | this.isADependency(entry) |
-        entry.getKey().getQualifiedName().trim() = name and
-        entry.getValue().getValue() = version
-        or
-        name = entry.getListItem().getValue().getValue().trim() and
-        version = "\"*\""
-      )
+      version = this.get("dependencies").(YamlMapping).lookup(name).(YamlScalar).getValue()
+      or
+      name =
+        this.get("libraryPathDependencies").(YamlCollection).getAChild().(YamlScalar).getValue() and
+      version = "\"*\""
       or
       name = this.getProperty("libraryPathDependencies") and
       version = "\"*\""
diff --git a/ql/ql/src/codeql_ql/ast/internal/AstNodes.qll b/ql/ql/src/codeql_ql/ast/internal/AstNodes.qll
index 33410830ae2..533d268127a 100644
--- a/ql/ql/src/codeql_ql/ast/internal/AstNodes.qll
+++ b/ql/ql/src/codeql_ql/ast/internal/AstNodes.qll
@@ -61,11 +61,6 @@ newtype TAstNode =
   TPredicateExpr(QL::PredicateExpr pe) or
   TAnnotation(QL::Annotation annot) or
   TAnnotationArg(QL::AnnotArg arg) or
-  TYamlComment(Yaml::Comment yc) or
-  TYamlEntry(Yaml::Entry ye) or
-  TYamlKey(Yaml::Key yk) or
-  TYamlListitem(Yaml::Listitem yli) or
-  TYamlValue(Yaml::Value yv) or
   TBuiltinClassless(string ret, string name, string args) { isBuiltinClassless(ret, name, args) } or
   TBuiltinMember(string qual, string ret, string name, string args) {
     isBuiltinMember(qual, ret, name, args)
@@ -87,15 +82,10 @@ class TCall = TPredicateCall or TMemberCall or TNoneCall or TAnyCall;
 
 class TTypeRef = TImport or TModuleExpr or TType;
 
-class TYamlNode = TYamlComment or TYamlEntry or TYamlKey or TYamlListitem or TYamlValue;
-
 class TSignatureExpr = TPredicateExpr or TType or TModuleExpr;
 
 class TComment = TQLDoc or TBlockComment or TLineComment;
 
-/** DEPRECATED: Alias for TYamlNode */
-deprecated class TYAMLNode = TYamlNode;
-
 private QL::AstNode toQLFormula(AST::AstNode n) {
   n = TConjunction(result) or
   n = TDisjunction(result) or
@@ -125,14 +115,6 @@ private QL::AstNode toQLExpr(AST::AstNode n) {
   n = TDontCare(result)
 }
 
-Yaml::AstNode toGenerateYaml(AST::AstNode n) {
-  n = TYamlComment(result) or
-  n = TYamlEntry(result) or
-  n = TYamlKey(result) or
-  n = TYamlListitem(result) or
-  n = TYamlValue(result)
-}
-
 Dbscheme::AstNode toDbscheme(AST::AstNode n) { n = TDBRelation(result) }
 
 /**
diff --git a/ql/ql/src/codeql_ql/ast/internal/TreeSitter.qll b/ql/ql/src/codeql_ql/ast/internal/TreeSitter.qll
index d15da37b4f2..76e96979cfd 100644
--- a/ql/ql/src/codeql_ql/ast/internal/TreeSitter.qll
+++ b/ql/ql/src/codeql_ql/ast/internal/TreeSitter.qll
@@ -1611,139 +1611,6 @@ module Dbscheme {
   }
 }
 
-module Yaml {
-  /** The base class for all AST nodes */
-  class AstNode extends @yaml_ast_node {
-    /** Gets a string representation of this element. */
-    string toString() { result = this.getAPrimaryQlClass() }
-
-    /** Gets the location of this element. */
-    final L::Location getLocation() { yaml_ast_node_info(this, _, _, result) }
-
-    /** Gets the parent of this element. */
-    final AstNode getParent() { yaml_ast_node_info(this, result, _, _) }
-
-    /** Gets the index of this node among the children of its parent. */
-    final int getParentIndex() { yaml_ast_node_info(this, _, result, _) }
-
-    /** Gets a field or child node of this node. */
-    AstNode getAFieldOrChild() { none() }
-
-    /** Gets the name of the primary QL class for this element. */
-    string getAPrimaryQlClass() { result = "???" }
-
-    /** Gets a comma-separated list of the names of the primary CodeQL classes to which this element belongs. */
-    string getPrimaryQlClasses() { result = concat(this.getAPrimaryQlClass(), ",") }
-  }
-
-  /** A token. */
-  class Token extends @yaml_token, AstNode {
-    /** Gets the value of this token. */
-    final string getValue() { yaml_tokeninfo(this, _, result) }
-
-    /** Gets a string representation of this element. */
-    final override string toString() { result = this.getValue() }
-
-    /** Gets the name of the primary QL class for this element. */
-    override string getAPrimaryQlClass() { result = "Token" }
-  }
-
-  /** A reserved word. */
-  class ReservedWord extends @yaml_reserved_word, Token {
-    /** Gets the name of the primary QL class for this element. */
-    final override string getAPrimaryQlClass() { result = "ReservedWord" }
-  }
-
-  /** A class representing `comment` nodes. */
-  class Comment extends @yaml_comment, AstNode {
-    /** Gets the name of the primary QL class for this element. */
-    final override string getAPrimaryQlClass() { result = "Comment" }
-
-    /** Gets the child of this node. */
-    final Value getChild() { yaml_comment_def(this, result) }
-
-    /** Gets a field or child node of this node. */
-    final override AstNode getAFieldOrChild() { yaml_comment_def(this, result) }
-  }
-
-  /** A class representing `entry` nodes. */
-  class Entry extends @yaml_entry, AstNode {
-    /** Gets the name of the primary QL class for this element. */
-    final override string getAPrimaryQlClass() { result = "Entry" }
-
-    /** Gets the child of this node. */
-    final AstNode getChild() { yaml_entry_def(this, result) }
-
-    /** Gets a field or child node of this node. */
-    final override AstNode getAFieldOrChild() { yaml_entry_def(this, result) }
-  }
-
-  /** A class representing `key` nodes. */
-  class Key extends @yaml_key__, AstNode {
-    /** Gets the name of the primary QL class for this element. */
-    final override string getAPrimaryQlClass() { result = "Key" }
-
-    /** Gets the `i`th child of this node. */
-    final AstNode getChild(int i) { yaml_key_child(this, i, result) }
-
-    /** Gets a field or child node of this node. */
-    final override AstNode getAFieldOrChild() { yaml_key_child(this, _, result) }
-  }
-
-  /** A class representing `keyvaluepair` nodes. */
-  class Keyvaluepair extends @yaml_keyvaluepair, AstNode {
-    /** Gets the name of the primary QL class for this element. */
-    final override string getAPrimaryQlClass() { result = "Keyvaluepair" }
-
-    /** Gets the node corresponding to the field `key`. */
-    final Key getKey() { yaml_keyvaluepair_def(this, result, _) }
-
-    /** Gets the node corresponding to the field `value`. */
-    final Value getValue() { yaml_keyvaluepair_def(this, _, result) }
-
-    /** Gets a field or child node of this node. */
-    final override AstNode getAFieldOrChild() {
-      yaml_keyvaluepair_def(this, result, _) or yaml_keyvaluepair_def(this, _, result)
-    }
-  }
-
-  /** A class representing `listitem` nodes. */
-  class Listitem extends @yaml_listitem, AstNode {
-    /** Gets the name of the primary QL class for this element. */
-    final override string getAPrimaryQlClass() { result = "Listitem" }
-
-    /** Gets the child of this node. */
-    final Value getChild() { yaml_listitem_def(this, result) }
-
-    /** Gets a field or child node of this node. */
-    final override AstNode getAFieldOrChild() { yaml_listitem_def(this, result) }
-  }
-
-  /** A class representing `simpleId` tokens. */
-  class SimpleId extends @yaml_token_simple_id, Token {
-    /** Gets the name of the primary QL class for this element. */
-    final override string getAPrimaryQlClass() { result = "SimpleId" }
-  }
-
-  /** A class representing `value` tokens. */
-  class Value extends @yaml_token_value, Token {
-    /** Gets the name of the primary QL class for this element. */
-    final override string getAPrimaryQlClass() { result = "Value" }
-  }
-
-  /** A class representing `yaml` nodes. */
-  class Yaml extends @yaml_yaml, AstNode {
-    /** Gets the name of the primary QL class for this element. */
-    final override string getAPrimaryQlClass() { result = "Yaml" }
-
-    /** Gets the `i`th child of this node. */
-    final Entry getChild(int i) { yaml_yaml_child(this, i, result) }
-
-    /** Gets a field or child node of this node. */
-    final override AstNode getAFieldOrChild() { yaml_yaml_child(this, _, result) }
-  }
-}
-
 module Blame {
   /** The base class for all AST nodes */
   class AstNode extends @blame_ast_node {
diff --git a/ql/ql/src/ql.dbscheme b/ql/ql/src/ql.dbscheme
index 2f98ed2d92d..97aa35b9ef5 100644
--- a/ql/ql/src/ql.dbscheme
+++ b/ql/ql/src/ql.dbscheme
@@ -62,6 +62,46 @@ case @diagnostic.severity of
 | 30 = @diagnostic_warning
 | 40 = @diagnostic_error
 ;
+
+/*- YAML -*/
+
+#keyset[parent, idx]
+yaml (unique int id: @yaml_node,
+      int kind: int ref,
+      int parent: @yaml_node_parent ref,
+      int idx: int ref,
+      string tag: string ref,
+      string tostring: string ref);
+
+case @yaml_node.kind of
+  0 = @yaml_scalar_node
+| 1 = @yaml_mapping_node
+| 2 = @yaml_sequence_node
+| 3 = @yaml_alias_node
+;
+
+@yaml_collection_node = @yaml_mapping_node | @yaml_sequence_node;
+
+@yaml_node_parent = @yaml_collection_node | @file;
+
+yaml_anchors (unique int node: @yaml_node ref,
+              string anchor: string ref);
+
+yaml_aliases (unique int alias: @yaml_alias_node ref,
+              string target: string ref);
+
+yaml_scalars (unique int scalar: @yaml_scalar_node ref,
+              int style: int ref,
+              string value: string ref);
+
+yaml_errors (unique int id: @yaml_error,
+             string message: string ref);
+
+yaml_locations(unique int locatable: @yaml_locatable ref,
+             int location: @location_default ref);
+
+@yaml_locatable = @yaml_node | @yaml_error;
+
 /*- QL dbscheme -*/
 @ql_add_expr_left_type = @ql_add_expr | @ql_aggregate | @ql_call_or_unqual_agg_expr | @ql_comp_term | @ql_conjunction | @ql_disjunction | @ql_expr_annotation | @ql_if_term | @ql_implication | @ql_in_expr | @ql_instance_of | @ql_literal | @ql_mul_expr | @ql_negation | @ql_par_expr | @ql_prefix_cast | @ql_qualified_expr | @ql_quantified | @ql_range | @ql_set_literal | @ql_special_call | @ql_super_ref | @ql_unary_expr | @ql_variable
 
@@ -1129,79 +1169,6 @@ dbscheme_ast_node_info(
   int loc: @location_default ref
 );
 
-/*- Yaml dbscheme -*/
-yaml_comment_def(
-  unique int id: @yaml_comment,
-  int child: @yaml_token_value ref
-);
-
-@yaml_entry_child_type = @yaml_comment | @yaml_keyvaluepair | @yaml_listitem
-
-yaml_entry_def(
-  unique int id: @yaml_entry,
-  int child: @yaml_entry_child_type ref
-);
-
-@yaml_key_child_type = @yaml_key__ | @yaml_token_simple_id
-
-#keyset[yaml_key__, index]
-yaml_key_child(
-  int yaml_key__: @yaml_key__ ref,
-  int index: int ref,
-  unique int child: @yaml_key_child_type ref
-);
-
-yaml_key_def(
-  unique int id: @yaml_key__
-);
-
-yaml_keyvaluepair_def(
-  unique int id: @yaml_keyvaluepair,
-  int key__: @yaml_key__ ref,
-  int value: @yaml_token_value ref
-);
-
-yaml_listitem_def(
-  unique int id: @yaml_listitem,
-  int child: @yaml_token_value ref
-);
-
-#keyset[yaml_yaml, index]
-yaml_yaml_child(
-  int yaml_yaml: @yaml_yaml ref,
-  int index: int ref,
-  unique int child: @yaml_entry ref
-);
-
-yaml_yaml_def(
-  unique int id: @yaml_yaml
-);
-
-yaml_tokeninfo(
-  unique int id: @yaml_token,
-  int kind: int ref,
-  string value: string ref
-);
-
-case @yaml_token.kind of
-  0 = @yaml_reserved_word
-| 1 = @yaml_token_simple_id
-| 2 = @yaml_token_value
-;
-
-
-@yaml_ast_node = @yaml_comment | @yaml_entry | @yaml_key__ | @yaml_keyvaluepair | @yaml_listitem | @yaml_token | @yaml_yaml
-
-@yaml_ast_node_parent = @file | @yaml_ast_node
-
-#keyset[parent, parent_index]
-yaml_ast_node_info(
-  unique int node: @yaml_ast_node ref,
-  int parent: @yaml_ast_node_parent ref,
-  int parent_index: int ref,
-  int loc: @location_default ref
-);
-
 /*- Blame dbscheme -*/
 #keyset[blame_blame_entry, index]
 blame_blame_entry_line(
diff --git a/ql/ql/src/qlpack.yml b/ql/ql/src/qlpack.yml
index 46eb43ff429..68991ef1c20 100644
--- a/ql/ql/src/qlpack.yml
+++ b/ql/ql/src/qlpack.yml
@@ -8,4 +8,5 @@ extractor: ql
 dependencies:
   codeql/typos: ${workspace}
   codeql/util: ${workspace}
+  codeql/yaml: ${workspace}
 warnOnImplicitThis: true
diff --git a/ql/tools/pre-finalize.cmd b/ql/tools/pre-finalize.cmd
new file mode 100644
index 00000000000..516084941c9
--- /dev/null
+++ b/ql/tools/pre-finalize.cmd
@@ -0,0 +1,10 @@
+@echo off
+
+type NUL && "%CODEQL_DIST%\codeql" database index-files ^
+    --include=**/qlpack.yml ^
+    --size-limit=5m ^
+    --language yaml ^
+    -- ^
+    "%CODEQL_EXTRACTOR_QL_WIP_DATABASE%"
+
+exit /b %ERRORLEVEL%
diff --git a/ql/tools/pre-finalize.sh b/ql/tools/pre-finalize.sh
new file mode 100755
index 00000000000..81fc6d58278
--- /dev/null
+++ b/ql/tools/pre-finalize.sh
@@ -0,0 +1,10 @@
+#!/bin/bash
+
+set -eu
+
+"$CODEQL_DIST/codeql" database index-files \
+    "--include=**/qlpack.yml" \
+    --size-limit=5m \
+    --language yaml \
+    -- \
+    "$CODEQL_EXTRACTOR_QL_WIP_DATABASE"
diff --git a/ql/tools/qltest.cmd b/ql/tools/qltest.cmd
index 15b42c8af35..d4429052645 100644
--- a/ql/tools/qltest.cmd
+++ b/ql/tools/qltest.cmd
@@ -11,4 +11,15 @@ type NUL && "%CODEQL_DIST%\codeql.exe" database index-files ^
     --working-dir=. ^
     "%CODEQL_EXTRACTOR_QL_WIP_DATABASE%"
 
+IF %ERRORLEVEL% NEQ 0 exit /b %ERRORLEVEL%
+
+type NUL && "%CODEQL_DIST%\codeql.exe" database index-files ^
+    --prune=**/*.testproj ^
+    --include-extension=.yml ^
+    --size-limit=5m ^
+    --language=yaml ^
+    --working-dir=. ^
+    "%CODEQL_EXTRACTOR_QL_WIP_DATABASE%"
+
 exit /b %ERRORLEVEL%
+
diff --git a/ql/tools/qltest.sh b/ql/tools/qltest.sh
index 3712b2a5a10..d6b9e0ff5ee 100755
--- a/ql/tools/qltest.sh
+++ b/ql/tools/qltest.sh
@@ -2,13 +2,20 @@
 
 set -eu
 
-exec "${CODEQL_DIST}/codeql" database index-files \
+"${CODEQL_DIST}/codeql" database index-files \
     --prune="**/*.testproj" \
     --include-extension=.ql \
     --include-extension=.qll \
     --include-extension=.dbscheme \
-    --include-extension=.yml \
     --size-limit=5m \
     --language=ql \
     --working-dir=.\
     "$CODEQL_EXTRACTOR_QL_WIP_DATABASE"
+
+exec "${CODEQL_DIST}/codeql" database index-files \
+    --prune="**/*.testproj" \
+    --include-extension=.yml \
+    --size-limit=5m \
+    --language=yaml \
+    --working-dir=.\
+    "$CODEQL_EXTRACTOR_QL_WIP_DATABASE"
diff --git a/ruby/ql/lib/ruby.dbscheme b/ruby/ql/lib/ruby.dbscheme
index a9b02f60315..f9f0f4023e4 100644
--- a/ruby/ql/lib/ruby.dbscheme
+++ b/ruby/ql/lib/ruby.dbscheme
@@ -62,6 +62,46 @@ case @diagnostic.severity of
 | 30 = @diagnostic_warning
 | 40 = @diagnostic_error
 ;
+
+/*- YAML -*/
+
+#keyset[parent, idx]
+yaml (unique int id: @yaml_node,
+      int kind: int ref,
+      int parent: @yaml_node_parent ref,
+      int idx: int ref,
+      string tag: string ref,
+      string tostring: string ref);
+
+case @yaml_node.kind of
+  0 = @yaml_scalar_node
+| 1 = @yaml_mapping_node
+| 2 = @yaml_sequence_node
+| 3 = @yaml_alias_node
+;
+
+@yaml_collection_node = @yaml_mapping_node | @yaml_sequence_node;
+
+@yaml_node_parent = @yaml_collection_node | @file;
+
+yaml_anchors (unique int node: @yaml_node ref,
+              string anchor: string ref);
+
+yaml_aliases (unique int alias: @yaml_alias_node ref,
+              string target: string ref);
+
+yaml_scalars (unique int scalar: @yaml_scalar_node ref,
+              int style: int ref,
+              string value: string ref);
+
+yaml_errors (unique int id: @yaml_error,
+             string message: string ref);
+
+yaml_locations(unique int locatable: @yaml_locatable ref,
+             int location: @location_default ref);
+
+@yaml_locatable = @yaml_node | @yaml_error;
+
 /*- Ruby dbscheme -*/
 @ruby_underscore_arg = @ruby_assignment | @ruby_binary | @ruby_conditional | @ruby_operator_assignment | @ruby_range | @ruby_unary | @ruby_underscore_primary
 
diff --git a/shared/tree-sitter-extractor/src/generator/prefix.dbscheme b/shared/tree-sitter-extractor/src/generator/prefix.dbscheme
index f371901ca6f..4bbfc8a0931 100644
--- a/shared/tree-sitter-extractor/src/generator/prefix.dbscheme
+++ b/shared/tree-sitter-extractor/src/generator/prefix.dbscheme
@@ -59,3 +59,43 @@ case @diagnostic.severity of
 | 30 = @diagnostic_warning
 | 40 = @diagnostic_error
 ;
+
+/*- YAML -*/
+
+#keyset[parent, idx]
+yaml (unique int id: @yaml_node,
+      int kind: int ref,
+      int parent: @yaml_node_parent ref,
+      int idx: int ref,
+      string tag: string ref,
+      string tostring: string ref);
+
+case @yaml_node.kind of
+  0 = @yaml_scalar_node
+| 1 = @yaml_mapping_node
+| 2 = @yaml_sequence_node
+| 3 = @yaml_alias_node
+;
+
+@yaml_collection_node = @yaml_mapping_node | @yaml_sequence_node;
+
+@yaml_node_parent = @yaml_collection_node | @file;
+
+yaml_anchors (unique int node: @yaml_node ref,
+              string anchor: string ref);
+
+yaml_aliases (unique int alias: @yaml_alias_node ref,
+              string target: string ref);
+
+yaml_scalars (unique int scalar: @yaml_scalar_node ref,
+              int style: int ref,
+              string value: string ref);
+
+yaml_errors (unique int id: @yaml_error,
+             string message: string ref);
+
+yaml_locations(unique int locatable: @yaml_locatable ref,
+             int location: @location_default ref);
+
+@yaml_locatable = @yaml_node | @yaml_error;
+