diff --git a/semgrep_output_v1.atd b/semgrep_output_v1.atd
index bfbcc2f3..d5747141 100644
--- a/semgrep_output_v1.atd
+++ b/semgrep_output_v1.atd
@@ -833,7 +833,8 @@ type skipped_rule = {
 (* coupling: with semgrep_metrics.atd performance section *)
 
 (* coupling: if you change the JSON schema below, you probably need to
- * also modify perf/run-benchmarks. Run locally  $ ./run-benchmarks --dummy --upload
+ * also modify perf/run-benchmarks.
+ * Run locally  $ ./run-benchmarks --dummy --upload
  *)
 type profile = {
     (* List of rules, including the one read but not run on any target.
@@ -1359,12 +1360,18 @@ type scan_metadata = {
 
 (* Sent by the CLI to the POST /api/cli/scans to create a scan. *)
 type scan_request = {
-    (* until 1.43ish, was 'meta: project_metadata;' before *)
-    meta: raw_json;
-    (* from 1.43 *)
-    ?project_metadata: project_metadata option; (* replacing meta *)
+    (* added in 1.43 as options, and mandatory since 1.100.0 (replacing meta) *)
+    project_metadata: project_metadata;
+    scan_metadata: scan_metadata;
+
+    (* added in 1.43 *)
     ?project_config: ci_config_from_repo option;
-    ?scan_metadata: scan_metadata option;
+    
+    (* deprecated: moved as an option in 1.100.0 and was duplicative of
+     * information in project_metadata and scan_metadata since 1.43.0
+     * old: 'meta: project_metadata;' before 1.43
+     *)
+    ?meta: raw_json option;
 }
 
 (* Response from the backend to the CLI to the POST /api/cli/scans *)
@@ -1942,7 +1949,6 @@ type apply_fixes_return <python decorator="dataclass(frozen=True)"> = {
   fixed_lines: (int * string list) list;
 }
 
-(* The parameters here pretty much match what's needed by Sarif_output.sarif_output. *)
 type sarif_format_params <python decorator="dataclass(frozen=True)"> = {
   hide_nudge: bool;
   engine_label: string;
diff --git a/semgrep_output_v1.jsonschema b/semgrep_output_v1.jsonschema
index 14d2c445..2b2f044a 100644
--- a/semgrep_output_v1.jsonschema
+++ b/semgrep_output_v1.jsonschema
@@ -1016,12 +1016,12 @@
     },
     "scan_request": {
       "type": "object",
-      "required": [ "meta" ],
+      "required": [ "project_metadata", "scan_metadata" ],
       "properties": {
-        "meta": { "$ref": "#/definitions/raw_json" },
         "project_metadata": { "$ref": "#/definitions/project_metadata" },
+        "scan_metadata": { "$ref": "#/definitions/scan_metadata" },
         "project_config": { "$ref": "#/definitions/ci_config_from_repo" },
-        "scan_metadata": { "$ref": "#/definitions/scan_metadata" }
+        "meta": { "$ref": "#/definitions/raw_json" }
       }
     },
     "scan_response": {
diff --git a/semgrep_output_v1.proto b/semgrep_output_v1.proto
index 0f3f54b9..858051ce 100644
--- a/semgrep_output_v1.proto
+++ b/semgrep_output_v1.proto
@@ -1,6 +1,6 @@
 // Generated by jsonschema2protobuf.  DO NOT EDIT!
 // Source file: semgrep_output_v1.jsonschema
-// Source file sha256 digest: 4259e2f9442c5d9ad81fe249f4ce630798fc9c008f2e6aab66329e21f4acd264
+// Source file sha256 digest: 3c5ed14031f0dd72ed2f739c26ab80f76a94337b5caa1da7e9a04d0facae95da
 
 syntax = "proto3";
 
@@ -383,10 +383,10 @@ message ScanMetadata {
 }
 
 message ScanRequest {
-  google.protobuf.Any meta = 3004443;
   ProjectMetadata project_metadata = 24255885;
-  CiConfigFromRepo project_config = 317758767;
   ScanMetadata scan_metadata = 76122041;
+  CiConfigFromRepo project_config = 317758767;
+  google.protobuf.Any meta = 3004443;
 }
 
 message ScanResponse {
diff --git a/semgrep_output_v1.py b/semgrep_output_v1.py
index f9339b9c..f44382fb 100644
--- a/semgrep_output_v1.py
+++ b/semgrep_output_v1.py
@@ -4923,32 +4923,31 @@ def to_json_string(self, **kw: Any) -> str:
 class ScanRequest:
     """Original type: scan_request = { ... }"""
 
-    meta: RawJson
-    project_metadata: Optional[ProjectMetadata] = None
+    project_metadata: ProjectMetadata
+    scan_metadata: ScanMetadata
     project_config: Optional[CiConfigFromRepo] = None
-    scan_metadata: Optional[ScanMetadata] = None
+    meta: Optional[RawJson] = None
 
     @classmethod
     def from_json(cls, x: Any) -> 'ScanRequest':
         if isinstance(x, dict):
             return cls(
-                meta=RawJson.from_json(x['meta']) if 'meta' in x else _atd_missing_json_field('ScanRequest', 'meta'),
-                project_metadata=ProjectMetadata.from_json(x['project_metadata']) if 'project_metadata' in x else None,
+                project_metadata=ProjectMetadata.from_json(x['project_metadata']) if 'project_metadata' in x else _atd_missing_json_field('ScanRequest', 'project_metadata'),
+                scan_metadata=ScanMetadata.from_json(x['scan_metadata']) if 'scan_metadata' in x else _atd_missing_json_field('ScanRequest', 'scan_metadata'),
                 project_config=CiConfigFromRepo.from_json(x['project_config']) if 'project_config' in x else None,
-                scan_metadata=ScanMetadata.from_json(x['scan_metadata']) if 'scan_metadata' in x else None,
+                meta=RawJson.from_json(x['meta']) if 'meta' in x else None,
             )
         else:
             _atd_bad_json('ScanRequest', x)
 
     def to_json(self) -> Any:
         res: Dict[str, Any] = {}
-        res['meta'] = (lambda x: x.to_json())(self.meta)
-        if self.project_metadata is not None:
-            res['project_metadata'] = (lambda x: x.to_json())(self.project_metadata)
+        res['project_metadata'] = (lambda x: x.to_json())(self.project_metadata)
+        res['scan_metadata'] = (lambda x: x.to_json())(self.scan_metadata)
         if self.project_config is not None:
             res['project_config'] = (lambda x: x.to_json())(self.project_config)
-        if self.scan_metadata is not None:
-            res['scan_metadata'] = (lambda x: x.to_json())(self.scan_metadata)
+        if self.meta is not None:
+            res['meta'] = (lambda x: x.to_json())(self.meta)
         return res
 
     @classmethod
diff --git a/semgrep_output_v1.ts b/semgrep_output_v1.ts
index 5aa73447..a9dc9115 100644
--- a/semgrep_output_v1.ts
+++ b/semgrep_output_v1.ts
@@ -560,10 +560,10 @@ export type ScanMetadata = {
 }
 
 export type ScanRequest = {
-  meta: RawJson;
-  project_metadata?: ProjectMetadata;
+  project_metadata: ProjectMetadata;
+  scan_metadata: ScanMetadata;
   project_config?: CiConfigFromRepo;
-  scan_metadata?: ScanMetadata;
+  meta?: RawJson;
 }
 
 export type ScanResponse = {
@@ -2767,19 +2767,19 @@ export function readScanMetadata(x: any, context: any = x): ScanMetadata {
 
 export function writeScanRequest(x: ScanRequest, context: any = x): any {
   return {
-    'meta': _atd_write_required_field('ScanRequest', 'meta', writeRawJson, x.meta, x),
-    'project_metadata': _atd_write_optional_field(writeProjectMetadata, x.project_metadata, x),
+    'project_metadata': _atd_write_required_field('ScanRequest', 'project_metadata', writeProjectMetadata, x.project_metadata, x),
+    'scan_metadata': _atd_write_required_field('ScanRequest', 'scan_metadata', writeScanMetadata, x.scan_metadata, x),
     'project_config': _atd_write_optional_field(writeCiConfigFromRepo, x.project_config, x),
-    'scan_metadata': _atd_write_optional_field(writeScanMetadata, x.scan_metadata, x),
+    'meta': _atd_write_optional_field(writeRawJson, x.meta, x),
   };
 }
 
 export function readScanRequest(x: any, context: any = x): ScanRequest {
   return {
-    meta: _atd_read_required_field('ScanRequest', 'meta', readRawJson, x['meta'], x),
-    project_metadata: _atd_read_optional_field(readProjectMetadata, x['project_metadata'], x),
+    project_metadata: _atd_read_required_field('ScanRequest', 'project_metadata', readProjectMetadata, x['project_metadata'], x),
+    scan_metadata: _atd_read_required_field('ScanRequest', 'scan_metadata', readScanMetadata, x['scan_metadata'], x),
     project_config: _atd_read_optional_field(readCiConfigFromRepo, x['project_config'], x),
-    scan_metadata: _atd_read_optional_field(readScanMetadata, x['scan_metadata'], x),
+    meta: _atd_read_optional_field(readRawJson, x['meta'], x),
   };
 }
 
diff --git a/semgrep_output_v1_j.ml b/semgrep_output_v1_j.ml
index aa29803d..3a80b162 100644
--- a/semgrep_output_v1_j.ml
+++ b/semgrep_output_v1_j.ml
@@ -404,10 +404,10 @@ type ci_config_from_repo = Semgrep_output_v1_t.ci_config_from_repo = {
 }
 
 type scan_request = Semgrep_output_v1_t.scan_request = {
-  meta: raw_json;
-  project_metadata: project_metadata option;
+  project_metadata: project_metadata;
+  scan_metadata: scan_metadata;
   project_config: ci_config_from_repo option;
-  scan_metadata: scan_metadata option
+  meta: raw_json option
 }
 
 type ci_env = Semgrep_output_v1_t.ci_env
@@ -15154,120 +15154,6 @@ let read_ci_config_from_repo = (
 )
 let ci_config_from_repo_of_string s =
   read_ci_config_from_repo (Yojson.Safe.init_lexer ()) (Lexing.from_string s)
-let write__scan_metadata_option = (
-  Atdgen_runtime.Oj_run.write_std_option (
-    write_scan_metadata
-  )
-)
-let string_of__scan_metadata_option ?(len = 1024) x =
-  let ob = Buffer.create len in
-  write__scan_metadata_option ob x;
-  Buffer.contents ob
-let read__scan_metadata_option = (
-  fun p lb ->
-    Yojson.Safe.read_space p lb;
-    match Yojson.Safe.start_any_variant p lb with
-      | `Edgy_bracket -> (
-          match Yojson.Safe.read_ident p lb with
-            | "None" ->
-              Yojson.Safe.read_space p lb;
-              Yojson.Safe.read_gt p lb;
-              (None : _ option)
-            | "Some" ->
-              Atdgen_runtime.Oj_run.read_until_field_value p lb;
-              let x = (
-                  read_scan_metadata
-                ) p lb
-              in
-              Yojson.Safe.read_space p lb;
-              Yojson.Safe.read_gt p lb;
-              (Some x : _ option)
-            | x ->
-              Atdgen_runtime.Oj_run.invalid_variant_tag p x
-        )
-      | `Double_quote -> (
-          match Yojson.Safe.finish_string p lb with
-            | "None" ->
-              (None : _ option)
-            | x ->
-              Atdgen_runtime.Oj_run.invalid_variant_tag p x
-        )
-      | `Square_bracket -> (
-          match Atdgen_runtime.Oj_run.read_string p lb with
-            | "Some" ->
-              Yojson.Safe.read_space p lb;
-              Yojson.Safe.read_comma p lb;
-              Yojson.Safe.read_space p lb;
-              let x = (
-                  read_scan_metadata
-                ) p lb
-              in
-              Yojson.Safe.read_space p lb;
-              Yojson.Safe.read_rbr p lb;
-              (Some x : _ option)
-            | x ->
-              Atdgen_runtime.Oj_run.invalid_variant_tag p x
-        )
-)
-let _scan_metadata_option_of_string s =
-  read__scan_metadata_option (Yojson.Safe.init_lexer ()) (Lexing.from_string s)
-let write__project_metadata_option = (
-  Atdgen_runtime.Oj_run.write_std_option (
-    write_project_metadata
-  )
-)
-let string_of__project_metadata_option ?(len = 1024) x =
-  let ob = Buffer.create len in
-  write__project_metadata_option ob x;
-  Buffer.contents ob
-let read__project_metadata_option = (
-  fun p lb ->
-    Yojson.Safe.read_space p lb;
-    match Yojson.Safe.start_any_variant p lb with
-      | `Edgy_bracket -> (
-          match Yojson.Safe.read_ident p lb with
-            | "None" ->
-              Yojson.Safe.read_space p lb;
-              Yojson.Safe.read_gt p lb;
-              (None : _ option)
-            | "Some" ->
-              Atdgen_runtime.Oj_run.read_until_field_value p lb;
-              let x = (
-                  read_project_metadata
-                ) p lb
-              in
-              Yojson.Safe.read_space p lb;
-              Yojson.Safe.read_gt p lb;
-              (Some x : _ option)
-            | x ->
-              Atdgen_runtime.Oj_run.invalid_variant_tag p x
-        )
-      | `Double_quote -> (
-          match Yojson.Safe.finish_string p lb with
-            | "None" ->
-              (None : _ option)
-            | x ->
-              Atdgen_runtime.Oj_run.invalid_variant_tag p x
-        )
-      | `Square_bracket -> (
-          match Atdgen_runtime.Oj_run.read_string p lb with
-            | "Some" ->
-              Yojson.Safe.read_space p lb;
-              Yojson.Safe.read_comma p lb;
-              Yojson.Safe.read_space p lb;
-              let x = (
-                  read_project_metadata
-                ) p lb
-              in
-              Yojson.Safe.read_space p lb;
-              Yojson.Safe.read_rbr p lb;
-              (Some x : _ option)
-            | x ->
-              Atdgen_runtime.Oj_run.invalid_variant_tag p x
-        )
-)
-let _project_metadata_option_of_string s =
-  read__project_metadata_option (Yojson.Safe.init_lexer ()) (Lexing.from_string s)
 let write__ci_config_from_repo_option = (
   Atdgen_runtime.Oj_run.write_std_option (
     write_ci_config_from_repo
@@ -15333,22 +15219,20 @@ let write_scan_request : _ -> scan_request -> _ = (
       is_first := false
     else
       Buffer.add_char ob ',';
-      Buffer.add_string ob "\"meta\":";
+      Buffer.add_string ob "\"project_metadata\":";
     (
-      write_raw_json
+      write_project_metadata
     )
-      ob x.meta;
-    (match x.project_metadata with None -> () | Some x ->
-      if !is_first then
-        is_first := false
-      else
-        Buffer.add_char ob ',';
-        Buffer.add_string ob "\"project_metadata\":";
-      (
-        write_project_metadata
-      )
-        ob x;
-    );
+      ob x.project_metadata;
+    if !is_first then
+      is_first := false
+    else
+      Buffer.add_char ob ',';
+      Buffer.add_string ob "\"scan_metadata\":";
+    (
+      write_scan_metadata
+    )
+      ob x.scan_metadata;
     (match x.project_config with None -> () | Some x ->
       if !is_first then
         is_first := false
@@ -15360,14 +15244,14 @@ let write_scan_request : _ -> scan_request -> _ = (
       )
         ob x;
     );
-    (match x.scan_metadata with None -> () | Some x ->
+    (match x.meta with None -> () | Some x ->
       if !is_first then
         is_first := false
       else
         Buffer.add_char ob ',';
-        Buffer.add_string ob "\"scan_metadata\":";
+        Buffer.add_string ob "\"meta\":";
       (
-        write_scan_metadata
+        write_raw_json
       )
         ob x;
     );
@@ -15381,10 +15265,10 @@ let read_scan_request = (
   fun p lb ->
     Yojson.Safe.read_space p lb;
     Yojson.Safe.read_lcurl p lb;
-    let field_meta = ref (None) in
     let field_project_metadata = ref (None) in
-    let field_project_config = ref (None) in
     let field_scan_metadata = ref (None) in
+    let field_project_config = ref (None) in
+    let field_meta = ref (None) in
     try
       Yojson.Safe.read_space p lb;
       Yojson.Safe.read_object_end lb;
@@ -15396,7 +15280,7 @@ let read_scan_request = (
           match len with
             | 4 -> (
                 if String.unsafe_get s pos = 'm' && String.unsafe_get s (pos+1) = 'e' && String.unsafe_get s (pos+2) = 't' && String.unsafe_get s (pos+3) = 'a' then (
-                  0
+                  3
                 )
                 else (
                   -1
@@ -15404,7 +15288,7 @@ let read_scan_request = (
               )
             | 13 -> (
                 if String.unsafe_get s pos = 's' && String.unsafe_get s (pos+1) = 'c' && String.unsafe_get s (pos+2) = 'a' && String.unsafe_get s (pos+3) = 'n' && String.unsafe_get s (pos+4) = '_' && String.unsafe_get s (pos+5) = 'm' && String.unsafe_get s (pos+6) = 'e' && String.unsafe_get s (pos+7) = 't' && String.unsafe_get s (pos+8) = 'a' && String.unsafe_get s (pos+9) = 'd' && String.unsafe_get s (pos+10) = 'a' && String.unsafe_get s (pos+11) = 't' && String.unsafe_get s (pos+12) = 'a' then (
-                  3
+                  1
                 )
                 else (
                   -1
@@ -15420,7 +15304,7 @@ let read_scan_request = (
               )
             | 16 -> (
                 if String.unsafe_get s pos = 'p' && String.unsafe_get s (pos+1) = 'r' && String.unsafe_get s (pos+2) = 'o' && String.unsafe_get s (pos+3) = 'j' && String.unsafe_get s (pos+4) = 'e' && String.unsafe_get s (pos+5) = 'c' && String.unsafe_get s (pos+6) = 't' && String.unsafe_get s (pos+7) = '_' && String.unsafe_get s (pos+8) = 'm' && String.unsafe_get s (pos+9) = 'e' && String.unsafe_get s (pos+10) = 't' && String.unsafe_get s (pos+11) = 'a' && String.unsafe_get s (pos+12) = 'd' && String.unsafe_get s (pos+13) = 'a' && String.unsafe_get s (pos+14) = 't' && String.unsafe_get s (pos+15) = 'a' then (
-                  1
+                  0
                 )
                 else (
                   -1
@@ -15435,23 +15319,21 @@ let read_scan_request = (
       (
         match i with
           | 0 ->
-            field_meta := (
+            field_project_metadata := (
               Some (
                 (
-                  read_raw_json
+                  read_project_metadata
                 ) p lb
               )
             );
           | 1 ->
-            if not (Yojson.Safe.read_null_if_possible p lb) then (
-              field_project_metadata := (
-                Some (
-                  (
-                    read_project_metadata
-                  ) p lb
-                )
-              );
-            )
+            field_scan_metadata := (
+              Some (
+                (
+                  read_scan_metadata
+                ) p lb
+              )
+            );
           | 2 ->
             if not (Yojson.Safe.read_null_if_possible p lb) then (
               field_project_config := (
@@ -15464,10 +15346,10 @@ let read_scan_request = (
             )
           | 3 ->
             if not (Yojson.Safe.read_null_if_possible p lb) then (
-              field_scan_metadata := (
+              field_meta := (
                 Some (
                   (
-                    read_scan_metadata
+                    read_raw_json
                   ) p lb
                 )
               );
@@ -15487,7 +15369,7 @@ let read_scan_request = (
             match len with
               | 4 -> (
                   if String.unsafe_get s pos = 'm' && String.unsafe_get s (pos+1) = 'e' && String.unsafe_get s (pos+2) = 't' && String.unsafe_get s (pos+3) = 'a' then (
-                    0
+                    3
                   )
                   else (
                     -1
@@ -15495,7 +15377,7 @@ let read_scan_request = (
                 )
               | 13 -> (
                   if String.unsafe_get s pos = 's' && String.unsafe_get s (pos+1) = 'c' && String.unsafe_get s (pos+2) = 'a' && String.unsafe_get s (pos+3) = 'n' && String.unsafe_get s (pos+4) = '_' && String.unsafe_get s (pos+5) = 'm' && String.unsafe_get s (pos+6) = 'e' && String.unsafe_get s (pos+7) = 't' && String.unsafe_get s (pos+8) = 'a' && String.unsafe_get s (pos+9) = 'd' && String.unsafe_get s (pos+10) = 'a' && String.unsafe_get s (pos+11) = 't' && String.unsafe_get s (pos+12) = 'a' then (
-                    3
+                    1
                   )
                   else (
                     -1
@@ -15511,7 +15393,7 @@ let read_scan_request = (
                 )
               | 16 -> (
                   if String.unsafe_get s pos = 'p' && String.unsafe_get s (pos+1) = 'r' && String.unsafe_get s (pos+2) = 'o' && String.unsafe_get s (pos+3) = 'j' && String.unsafe_get s (pos+4) = 'e' && String.unsafe_get s (pos+5) = 'c' && String.unsafe_get s (pos+6) = 't' && String.unsafe_get s (pos+7) = '_' && String.unsafe_get s (pos+8) = 'm' && String.unsafe_get s (pos+9) = 'e' && String.unsafe_get s (pos+10) = 't' && String.unsafe_get s (pos+11) = 'a' && String.unsafe_get s (pos+12) = 'd' && String.unsafe_get s (pos+13) = 'a' && String.unsafe_get s (pos+14) = 't' && String.unsafe_get s (pos+15) = 'a' then (
-                    1
+                    0
                   )
                   else (
                     -1
@@ -15526,23 +15408,21 @@ let read_scan_request = (
         (
           match i with
             | 0 ->
-              field_meta := (
+              field_project_metadata := (
                 Some (
                   (
-                    read_raw_json
+                    read_project_metadata
                   ) p lb
                 )
               );
             | 1 ->
-              if not (Yojson.Safe.read_null_if_possible p lb) then (
-                field_project_metadata := (
-                  Some (
-                    (
-                      read_project_metadata
-                    ) p lb
-                  )
-                );
-              )
+              field_scan_metadata := (
+                Some (
+                  (
+                    read_scan_metadata
+                  ) p lb
+                )
+              );
             | 2 ->
               if not (Yojson.Safe.read_null_if_possible p lb) then (
                 field_project_config := (
@@ -15555,10 +15435,10 @@ let read_scan_request = (
               )
             | 3 ->
               if not (Yojson.Safe.read_null_if_possible p lb) then (
-                field_scan_metadata := (
+                field_meta := (
                   Some (
                     (
-                      read_scan_metadata
+                      read_raw_json
                     ) p lb
                   )
                 );
@@ -15572,10 +15452,10 @@ let read_scan_request = (
     with Yojson.End_of_object -> (
         (
           {
-            meta = (match !field_meta with Some x -> x | None -> Atdgen_runtime.Oj_run.missing_field p "meta");
-            project_metadata = !field_project_metadata;
+            project_metadata = (match !field_project_metadata with Some x -> x | None -> Atdgen_runtime.Oj_run.missing_field p "project_metadata");
+            scan_metadata = (match !field_scan_metadata with Some x -> x | None -> Atdgen_runtime.Oj_run.missing_field p "scan_metadata");
             project_config = !field_project_config;
-            scan_metadata = !field_scan_metadata;
+            meta = !field_meta;
           }
          : scan_request)
       )
diff --git a/semgrep_output_v1_j.mli b/semgrep_output_v1_j.mli
index 368c0e2d..e3ed8187 100644
--- a/semgrep_output_v1_j.mli
+++ b/semgrep_output_v1_j.mli
@@ -404,10 +404,10 @@ type ci_config_from_repo = Semgrep_output_v1_t.ci_config_from_repo = {
 }
 
 type scan_request = Semgrep_output_v1_t.scan_request = {
-  meta: raw_json;
-  project_metadata: project_metadata option;
+  project_metadata: project_metadata;
+  scan_metadata: scan_metadata;
   project_config: ci_config_from_repo option;
-  scan_metadata: scan_metadata option
+  meta: raw_json option
 }
 
 type ci_env = Semgrep_output_v1_t.ci_env