feat(text): add text_audit spell-check and dry-run replacement simulation

- Adds 	ext_audit operation under ocs_read, control bridge, and headless server
- Implements pairs / dry_run_pairs simulation returning diffs, coordinates, and unmatched queries
- Implements check_terms suspect matching and dictionary vocabulary verification
- Adds dry_run: true to 	ext_replace to preview modifications without mutating entities or pushing undo
- Supports bounds, layers, handles, and scope filtering
- Updates MCP tool definitions, schemas, and automation test suites

docs/automation/mcp_smoke.py

@@ -52,16 +52,18 @@ def legacy(server: Path) -> None:
     names = set(definitions)
     assert names == TOOLS, names
     execute_request = definitions["ocs_execute"]["inputSchema"]["properties"]["request"]
-    assert len(execute_request["oneOf"]) == 38
+    assert len(execute_request["oneOf"]) == 39
     op_enum = execute_request["properties"]["op"]["enum"]
     for shipped in ("entities_create", "entities_delete", "entities_transform",
                     "block_define", "block_delete", "file_identity", "xdata_set",
                     "view_focus", "wblock", "plot",
                     "entities_copy_to", "group_create", "selection_set_save",
                     "selection_set_load", "close", "sysvar", "layout_create",
-                    "page_setup_set"):
+                    "page_setup_set", "text_replace"):
         assert shipped in op_enum, shipped
     assert "xdata_get" in definitions["ocs_read"]["inputSchema"]["properties"]["op"]["enum"]
+    assert "text_search" in definitions["ocs_read"]["inputSchema"]["properties"]["op"]["enum"]
+    assert "text_audit" in definitions["ocs_read"]["inputSchema"]["properties"]["op"]["enum"]
     assert execute_request["properties"]["steps"]["maxItems"] == 64
     assert execute_request["properties"]["cmd"]["examples"][0] == "LINE 0,0 10,10"
     assert "set_properties" in execute_request["properties"]["op"]["enum"]

docs/automation/native.md

@@ -33,7 +33,7 @@ Two request styles share the channel, told apart by the `protocol` field:
 
 | Style | Shape | Operations |
 |---|---|---|
-| protocol 1 | `{"protocol":1,"request_id":"…","document_id":N,"op":"…"}` — the same requests and replies as `ocs_execute` / `ocs_read`, described in the README | `new`, `open`, `save`, `save_verified`, `activate`, `select`, `run`, `start`, `input`, `cancel`, `stop`, `action`, `property`, `set_properties`, `embed_image`, `undo`, `redo`; reads `state`, `capabilities`, `audit`, `query`, `entities`, `records`, `record_schema`, `layers`, `header`, `properties`, `measure`, `history`, `commands`, `events`, `operation` |
+| protocol 1 | `{"protocol":1,"request_id":"…","document_id":N,"op":"…"}` — the same requests and replies as `ocs_execute` / `ocs_read`, described in the README | `new`, `open`, `save`, `save_verified`, `activate`, `select`, `run`, `start`, `input`, `cancel`, `stop`, `action`, `property`, `set_properties`, `embed_image`, `undo`, `redo`, `text_replace`; reads `state`, `capabilities`, `audit`, `text_audit`, `text_search`, `query`, `entities`, `records`, `record_schema`, `layers`, `header`, `properties`, `measure`, `history`, `commands`, `events`, `operation` |
 | legacy | `{"op":"…"}` without `protocol` | `new`, `open`, `run`, `entities`, `audit`, `query`, `records`, `record_schema`, `capabilities`, `layers`, `header`, `select`, `save`, `undo`, `redo` |
 
 The two styles differ in how a waiting command is treated. A protocol-1 `run`

src/app/automation.rs

@@ -680,6 +680,7 @@ impl OpenCADStudio {
             "audit" => self.document_audit(&req),
             "query" => self.entity_query(&req),
             "text_search" => self.automation_text_search(&req),
+            "text_audit" => self.automation_text_audit(&req),
             "text_replace" => self.automation_text_replace(&req),
             "records" => self.record_query(&req),
             "record_schema" => self.record_schema(&req),

src/app/control/mod.rs

@@ -472,6 +472,7 @@ impl OpenCADStudio {
                 | "get_selection"
                 | "audit"
                 | "text_search"
+                | "text_audit"
         );
         if !query && !self.control.enabled {
             return (
@@ -731,6 +732,7 @@ impl OpenCADStudio {
                 "xdata_get" => self.xdata_read(&req),
                 "get_selection" => self.control_get_selection(),
                 "text_search" => self.control_text_search(&req).unwrap_or_else(|e| e),
+                "text_audit" => self.control_text_audit(&req).unwrap_or_else(|e| e),
                 "history" => {
                     json!({"ok":true,"entries":self.command_line.history.iter().map(|e|json!({"kind":format!("{:?}",e.kind),"text":e.text})).collect::<Vec<_>>()})
                 }

src/app/control/p1_tests.rs

@@ -655,3 +655,112 @@ fn text_replace_op_batch_replaces_preserves_formatting_and_undoes() {
     assert_eq!(q_orig2["count"], 1);
 }
 
+#[test]
+fn text_audit_op_simulates_dry_run_checks_terms_and_dictionary() {
+    let mut app = OpenCADStudio::new_for_test();
+    app.automation_op(r#"{"op":"new"}"#);
+    let r = mutate(
+        &mut app,
+        r#"{"protocol":1,"op":"entities_create","request_id":"ta_c1","document_id":{doc},"entities":[
+            {"type":"Text","position":[0,0,0],"value":"CIRTUITS 28-09-2026","layer":"0"},
+            {"type":"MText","position":[10,0,0],"value":"{\\fCentury Gothic;CUVE EAU NON TRAITE}","layer":"0"},
+            {"type":"Text","position":[20,0,0],"value":"POMPE A EAU","layer":"0"}
+        ]}"#,
+    );
+    assert_eq!(r["ok"], true, "{}", r["error"]);
+
+    // Test text_audit with pairs, check_terms, and dictionary
+    let audit_res = app.automation_op(
+        r#"{
+            "op":"text_audit",
+            "pairs":[
+                {"find":"CIRTUITS","replace":"CIRCUITS"},
+                {"find":"NON TRAITE","replace":"NON TRAITÉE"},
+                {"find":"INEXISTANT_PAIR","replace":"REPLACEMENT"}
+            ],
+            "check_terms":["CIRTUITS", "NON TRAITE", "INEXISTANT_TERM"],
+            "dictionary":["EAU", "POMPE", "28-09-2026"]
+        }"#,
+    );
+    assert_eq!(audit_res["ok"], true, "{}", audit_res["error"]);
+
+    // Check summary
+    assert_eq!(audit_res["summary"]["pairs_total"], 3);
+    assert_eq!(audit_res["summary"]["pairs_unmatched"], 1);
+    assert_eq!(audit_res["summary"]["check_terms_total"], 3);
+    assert_eq!(audit_res["summary"]["check_terms_found"], 2);
+
+    // Unmatched reporting
+    assert_eq!(audit_res["unmatched_pairs"], json!(["INEXISTANT_PAIR"]));
+    assert_eq!(audit_res["unmatched_check_terms"], json!(["INEXISTANT_TERM"]));
+
+    // Simulated changes has 2 entries (Text and MText)
+    let changes = audit_res["simulated_changes"].as_array().unwrap();
+    assert_eq!(changes.len(), 2);
+    assert_eq!(changes[0]["find"], "CIRTUITS");
+    assert_eq!(changes[0]["replace"], "CIRCUITS");
+    assert_eq!(changes[0]["replaced"], 1);
+    assert!(changes[1]["after"].as_str().unwrap().contains("NON TRAITÉE"));
+
+    // Suspect matches
+    let suspects = audit_res["suspect_matches"].as_array().unwrap();
+    assert_eq!(suspects.len(), 2);
+
+    // Verify document was NOT mutated (pure read op)
+    let q = app.automation_op(r#"{"op":"text_search","find":"CIRTUITS"}"#);
+    assert_eq!(q["ok"], true);
+    assert_eq!(q["count"], 1);
+}
+
+#[test]
+fn text_replace_op_supports_dry_run_without_mutating_or_undo() {
+    let mut app = OpenCADStudio::new_for_test();
+    app.automation_op(r#"{"op":"new"}"#);
+    let r = mutate(
+        &mut app,
+        r#"{"protocol":1,"op":"entities_create","request_id":"tr_dry1","document_id":{doc},"entities":[
+            {"type":"Text","position":[0,0,0],"value":"TEST BEFORE REPLACE","layer":"0"}
+        ]}"#,
+    );
+    assert_eq!(r["ok"], true, "{}", r["error"]);
+
+    // Run text_replace with dry_run = true
+    let dry_res = mutate(
+        &mut app,
+        r#"{"protocol":1,"op":"text_replace","request_id":"tr_sim1","document_id":{doc},"find":"BEFORE","replace":"AFTER","dry_run":true}"#,
+    );
+    assert_eq!(dry_res["ok"], true, "{}", dry_res["error"]);
+    assert_eq!(dry_res["result"]["dry_run"], true);
+    assert_eq!(dry_res["result"]["replaced"], 1);
+    assert_eq!(dry_res["result"]["entities_changed"], 1);
+
+    // Verify the document was NOT modified
+    let q_before = app.automation_op(r#"{"op":"text_search","find":"TEST BEFORE REPLACE"}"#);
+    assert_eq!(q_before["ok"], true);
+    assert_eq!(q_before["count"], 1);
+
+    let q_after = app.automation_op(r#"{"op":"text_search","find":"TEST AFTER REPLACE"}"#);
+    assert_eq!(q_after["ok"], true);
+    assert_eq!(q_after["count"], 0);
+
+    // Now run with dry_run = false
+    let real_res = mutate(
+        &mut app,
+        r#"{"protocol":1,"op":"text_replace","request_id":"tr_real1","document_id":{doc},"find":"BEFORE","replace":"AFTER","dry_run":false}"#,
+    );
+    assert_eq!(real_res["ok"], true, "{}", real_res["error"]);
+    assert_eq!(real_res["result"]["replaced"], 1);
+
+    // Now it was modified
+    let q_after2 = app.automation_op(r#"{"op":"text_search","find":"TEST AFTER REPLACE"}"#);
+    assert_eq!(q_after2["ok"], true);
+    assert_eq!(q_after2["count"], 1);
+
+    // Undo restores it
+    app.automation_op(r#"{"op":"undo"}"#);
+    let q_undone = app.automation_op(r#"{"op":"text_search","find":"TEST BEFORE REPLACE"}"#);
+    assert_eq!(q_undone["ok"], true);
+    assert_eq!(q_undone["count"], 1);
+}
+
+

src/app/control/text_ops.rs

@@ -758,7 +758,14 @@ impl OpenCADStudio {
         let limit = req["limit"].as_u64().unwrap_or(500).min(5000) as usize;
 
         let matcher = TextMatcher::new(find.to_string(), match_case, whole_word, ignore_accents);
-        let i = self.active_tab;
+        let i = if let Some(doc_id) = req.get("document_id").and_then(|v| v.as_u64()) {
+            self.tabs
+                .iter()
+                .position(|t| t.id == doc_id)
+                .ok_or_else(|| failure("document_not_found", "Specified document_id not found"))?
+        } else {
+            self.active_tab
+        };
         let scene = &self.tabs[i].scene;
         let doc = &scene.document;
 
@@ -870,13 +877,342 @@ impl OpenCADStudio {
         }))
     }
 
+    /// `text_audit` — comprehensive text quality check, spell-check, and replacement dry-run.
+    pub(crate) fn control_text_audit(&self, req: &Value) -> Result<Value, Value> {
+        let i = if let Some(doc_id) = req.get("document_id").and_then(|v| v.as_u64()) {
+            self.tabs
+                .iter()
+                .position(|t| t.id == doc_id)
+                .ok_or_else(|| failure("document_not_found", "Specified document_id not found"))?
+        } else {
+            self.active_tab
+        };
+
+        let match_case = req["match_case"].as_bool().unwrap_or(false);
+        let whole_word = req["whole_word"].as_bool().unwrap_or(false);
+        let ignore_accents = req["ignore_accents"].as_bool().unwrap_or(!match_case);
+        let scope = req["scope"].as_str().unwrap_or("all");
+        let layer_filter = req["layer"].as_str();
+        let handles_filter = parse_handles_filter(req);
+        let types_filter = parse_types_filter(req);
+        let bounds_filter = parse_bounds_filter(req)?;
+        let limit = req["limit"].as_u64().unwrap_or(1000).min(10000) as usize;
+
+        // Parse dry-run replacement pairs if supplied
+        let mut pairs: Vec<(String, String)> = Vec::new();
+        let pairs_val = req.get("pairs").or_else(|| req.get("dry_run_pairs"));
+        if let Some(pair_array) = pairs_val.and_then(|v| v.as_array()) {
+            for item in pair_array {
+                let find = item["find"].as_str().unwrap_or("");
+                let replace = item["replace"].as_str().unwrap_or("");
+                if !find.is_empty() {
+                    pairs.push((find.to_string(), replace.to_string()));
+                }
+            }
+        }
+
+        // Parse check terms if supplied
+        let mut check_terms: Vec<String> = Vec::new();
+        if let Some(terms_array) = req.get("check_terms").and_then(|v| v.as_array()) {
+            for item in terms_array {
+                if let Some(t) = item.as_str() {
+                    if !t.is_empty() {
+                        check_terms.push(t.to_string());
+                    }
+                }
+            }
+        }
+
+        // Parse dictionary if supplied
+        let mut dictionary: Vec<String> = Vec::new();
+        if let Some(dict_array) = req.get("dictionary").and_then(|v| v.as_array()) {
+            for item in dict_array {
+                if let Some(w) = item.as_str() {
+                    if !w.is_empty() {
+                        dictionary.push(w.to_string());
+                    }
+                }
+            }
+        }
+
+        let pair_matchers: Vec<(TextMatcher, String)> = pairs
+            .iter()
+            .map(|(f, r)| {
+                (
+                    TextMatcher::new(f.clone(), match_case, whole_word, ignore_accents),
+                    r.clone(),
+                )
+            })
+            .collect();
+
+        let check_matchers: Vec<TextMatcher> = check_terms
+            .iter()
+            .map(|t| TextMatcher::new(t.clone(), match_case, whole_word, ignore_accents))
+            .collect();
+
+        let dict_matchers: Vec<TextMatcher> = dictionary
+            .iter()
+            .map(|w| TextMatcher::new(w.clone(), false, true, true))
+            .collect();
+
+        let mut pair_hit_counts = vec![0usize; pair_matchers.len()];
+        let mut check_hit_counts = vec![0usize; check_matchers.len()];
+
+        let scene = &self.tabs[i].scene;
+        let doc = &scene.document;
+
+        let mut entities_scanned = 0usize;
+        let mut entities_matched = 0usize;
+        let mut total_occurrences = 0usize;
+        let mut simulated_changes = Vec::new();
+        let mut suspect_matches = Vec::new();
+        let mut unrecognized_words = Vec::new();
+
+        for entity in doc.entities() {
+            let common = entity.common();
+            let handle = common.handle;
+
+            let in_active = scene.entity_belongs_to_active_space(handle);
+            match scope {
+                "active_space" | "model_space" if !in_active => continue,
+                "blocks" if in_active => continue,
+                _ => {}
+            }
+
+            if let Some(l) = layer_filter {
+                if !common.layer.eq_ignore_ascii_case(l) {
+                    continue;
+                }
+            }
+
+            if let Some(ref h_list) = handles_filter {
+                if !h_list.contains(&handle) {
+                    continue;
+                }
+            }
+
+            if let Some(ref t_list) = types_filter {
+                if !t_list
+                    .iter()
+                    .any(|t| crate::app::automation::entity_type_matches(entity, t))
+                {
+                    continue;
+                }
+            }
+
+            if let Some(b) = bounds_filter {
+                let (min, max) = crate::scene::convert::tess::entity_bounds_in(doc, entity);
+                if max[0] < b[0] || max[1] < b[1] || min[0] > b[2] || min[1] > b[3] {
+                    continue;
+                }
+            }
+
+            let Some((raw_val, plain_text, pos)) = entity_text_info(entity, doc) else {
+                continue;
+            };
+
+            entities_scanned += 1;
+            let mut entity_had_match = false;
+
+            // 1. Dry run pairs simulation
+            if !pair_matchers.is_empty() {
+                match entity {
+                    EntityType::MText(_) => {
+                        let mut cur_raw = raw_val.clone();
+                        for (idx, (matcher, replacement)) in pair_matchers.iter().enumerate() {
+                            let (new_raw, count) =
+                                replace_mtext_safe(&cur_raw, matcher, replacement, true);
+                            if count > 0 {
+                                pair_hit_counts[idx] += count;
+                                total_occurrences += count;
+                                entity_had_match = true;
+                                if simulated_changes.len() < limit {
+                                    simulated_changes.push(json!({
+                                        "handle": format!("{:X}", handle.value()),
+                                        "type": "MText",
+                                        "layer": common.layer,
+                                        "position": pos,
+                                        "find": pairs[idx].0,
+                                        "replace": pairs[idx].1,
+                                        "before": cur_raw,
+                                        "after": new_raw.clone(),
+                                        "replaced": count,
+                                    }));
+                                }
+                                cur_raw = new_raw;
+                            }
+                        }
+                    }
+                    _ => {
+                        let mut cur_text = plain_text.clone();
+                        for (idx, (matcher, replacement)) in pair_matchers.iter().enumerate() {
+                            let (new_text, count) =
+                                matcher.replace_all_in(&cur_text, replacement, true);
+                            if count > 0 {
+                                pair_hit_counts[idx] += count;
+                                total_occurrences += count;
+                                entity_had_match = true;
+                                if simulated_changes.len() < limit {
+                                    simulated_changes.push(json!({
+                                        "handle": format!("{:X}", handle.value()),
+                                        "type": crate::entities::names::ui_name(entity),
+                                        "layer": common.layer,
+                                        "position": pos,
+                                        "find": pairs[idx].0,
+                                        "replace": pairs[idx].1,
+                                        "before": cur_text,
+                                        "after": new_text.clone(),
+                                        "replaced": count,
+                                    }));
+                                }
+                                cur_text = new_text;
+                            }
+                        }
+                    }
+                }
+            }
+
+            // 2. Check terms
+            for (idx, matcher) in check_matchers.iter().enumerate() {
+                if matcher.matches_text_or_raw(&plain_text, &raw_val) {
+                    check_hit_counts[idx] += 1;
+                    entity_had_match = true;
+                    if suspect_matches.len() < limit {
+                        suspect_matches.push(json!({
+                            "handle": format!("{:X}", handle.value()),
+                            "type": crate::entities::names::ui_name(entity),
+                            "layer": common.layer,
+                            "position": pos,
+                            "term": check_terms[idx],
+                            "plain_text": plain_text,
+                        }));
+                    }
+                }
+            }
+
+            // 3. Dictionary check
+            if !dict_matchers.is_empty() {
+                for word in plain_text.split(|c: char| !c.is_alphabetic()) {
+                    let w = word.trim();
+                    if w.len() >= 3 && !dict_matchers.iter().any(|dm| dm.matches(w)) {
+                        if unrecognized_words.len() < limit
+                            && !unrecognized_words
+                                .iter()
+                                .any(|item: &Value| item["word"].as_str() == Some(w))
+                        {
+                            unrecognized_words.push(json!({
+                                "word": w,
+                                "handle": format!("{:X}", handle.value()),
+                                "position": pos,
+                            }));
+                        }
+                    }
+                }
+            }
+
+            // Check Insert attributes
+            if let EntityType::Insert(insert) = entity {
+                for attr in &insert.attributes {
+                    let raw = attr.get_value();
+                    let plain = decode_dxf_escapes(raw);
+
+                    for (idx, (matcher, replacement)) in pair_matchers.iter().enumerate() {
+                        let (new_text, count) =
+                            matcher.replace_all_in(&plain, replacement, true);
+                        if count > 0 {
+                            pair_hit_counts[idx] += count;
+                            total_occurrences += count;
+                            entity_had_match = true;
+                            if simulated_changes.len() < limit {
+                                simulated_changes.push(json!({
+                                    "handle": format!("{:X}", handle.value()),
+                                    "type": "Insert",
+                                    "attribute_tag": attr.tag,
+                                    "layer": common.layer,
+                                    "position": [insert.insert_point.x, insert.insert_point.y, insert.insert_point.z],
+                                    "find": pairs[idx].0,
+                                    "replace": pairs[idx].1,
+                                    "before": plain.clone(),
+                                    "after": new_text,
+                                    "replaced": count,
+                                }));
+                            }
+                        }
+                    }
+
+                    for (idx, matcher) in check_matchers.iter().enumerate() {
+                        if matcher.matches_text_or_raw(&plain, raw) {
+                            check_hit_counts[idx] += 1;
+                            entity_had_match = true;
+                            if suspect_matches.len() < limit {
+                                suspect_matches.push(json!({
+                                    "handle": format!("{:X}", handle.value()),
+                                    "type": "Insert",
+                                    "attribute_tag": attr.tag,
+                                    "layer": common.layer,
+                                    "position": [insert.insert_point.x, insert.insert_point.y, insert.insert_point.z],
+                                    "term": check_terms[idx],
+                                    "plain_text": plain,
+                                }));
+                            }
+                        }
+                    }
+                }
+            }
+
+            if entity_had_match {
+                entities_matched += 1;
+            }
+        }
+
+        // Unmatched pairs / queries
+        let unmatched_pairs: Vec<String> = pair_hit_counts
+            .iter()
+            .enumerate()
+            .filter(|(_, &count)| count == 0)
+            .map(|(idx, _)| pairs[idx].0.clone())
+            .collect();
+
+        let unmatched_check_terms: Vec<String> = check_hit_counts
+            .iter()
+            .enumerate()
+            .filter(|(_, &count)| count == 0)
+            .map(|(idx, _)| check_terms[idx].clone())
+            .collect();
+
+        Ok(json!({
+            "ok": true,
+            "summary": {
+                "entities_scanned": entities_scanned,
+                "entities_matched": entities_matched,
+                "occurrences_matched": total_occurrences,
+                "pairs_total": pairs.len(),
+                "pairs_unmatched": unmatched_pairs.len(),
+                "check_terms_total": check_terms.len(),
+                "check_terms_found": check_terms.len() - unmatched_check_terms.len(),
+            },
+            "unmatched_pairs": unmatched_pairs,
+            "unmatched_check_terms": unmatched_check_terms,
+            "simulated_changes": simulated_changes,
+            "suspect_matches": suspect_matches,
+            "unrecognized_words": unrecognized_words,
+        }))
+    }
+
     /// Execute text replace across candidates with single-transaction undo support.
     pub(crate) fn execute_text_replace(
         &mut self,
         req: &Value,
         push_undo: bool,
     ) -> Result<Value, Value> {
-        let i = self.active_tab;
+        let i = if let Some(doc_id) = req.get("document_id").and_then(|v| v.as_u64()) {
+            self.tabs
+                .iter()
+                .position(|t| t.id == doc_id)
+                .ok_or_else(|| failure("document_not_found", "Specified document_id not found"))?
+        } else {
+            self.active_tab
+        };
 
         // Parse search/replace pairs
         let mut pairs: Vec<(String, String)> = Vec::new();
@@ -905,6 +1241,7 @@ impl OpenCADStudio {
         let match_case = req["match_case"].as_bool().unwrap_or(false);
         let whole_word = req["whole_word"].as_bool().unwrap_or(false);
         let ignore_accents = req["ignore_accents"].as_bool().unwrap_or(!match_case);
+        let dry_run = req["dry_run"].as_bool().unwrap_or(false);
         let replace_all = req["replace_all"].as_bool().unwrap_or(true);
         let scope = req["scope"].as_str().unwrap_or("all");
         let layer_filter = req["layer"].as_str();
@@ -917,7 +1254,7 @@ impl OpenCADStudio {
             .map(|(f, r)| (TextMatcher::new(f, match_case, whole_word, ignore_accents), r))
             .collect();
 
-        if push_undo {
+        if push_undo && !dry_run {
             self.push_undo_snapshot(i, "TEXT REPLACE");
         }
 
@@ -998,9 +1335,11 @@ impl OpenCADStudio {
                             if before_val.is_none() {
                                 before_val = Some(text.value.clone());
                             }
-                            text.value = new_val;
+                            if !dry_run {
+                                text.value = new_val.clone();
+                            }
                             entity_replaced += count;
-                            after_val = Some(text.value.clone());
+                            after_val = Some(new_val);
                         } else {
                             // Check if matching decoded DXF escapes
                             let decoded = decode_dxf_escapes(&text.value);
@@ -1011,9 +1350,11 @@ impl OpenCADStudio {
                                     if before_val.is_none() {
                                         before_val = Some(text.value.clone());
                                     }
-                                    text.value = new_val;
+                                    if !dry_run {
+                                        text.value = new_val.clone();
+                                    }
                                     entity_replaced += c;
-                                    after_val = Some(text.value.clone());
+                                    after_val = Some(new_val);
                                 }
                             }
                         }
@@ -1027,9 +1368,11 @@ impl OpenCADStudio {
                             if before_val.is_none() {
                                 before_val = Some(mtext.value.clone());
                             }
-                            mtext.value = new_val;
+                            if !dry_run {
+                                mtext.value = new_val.clone();
+                            }
                             entity_replaced += count;
-                            after_val = Some(mtext.value.clone());
+                            after_val = Some(new_val);
                         }
                     }
                 }
@@ -1041,9 +1384,11 @@ impl OpenCADStudio {
                             if before_val.is_none() {
                                 before_val = Some(ad.default_value.clone());
                             }
-                            ad.default_value = new_val;
+                            if !dry_run {
+                                ad.default_value = new_val.clone();
+                            }
                             entity_replaced += count;
-                            after_val = Some(ad.default_value.clone());
+                            after_val = Some(new_val);
                         }
                     }
                 }
@@ -1055,9 +1400,11 @@ impl OpenCADStudio {
                             if before_val.is_none() {
                                 before_val = Some(ae.get_value().to_string());
                             }
-                            ae.set_value(new_val);
+                            if !dry_run {
+                                ae.set_value(new_val.clone());
+                            }
                             entity_replaced += count;
-                            after_val = Some(ae.get_value().to_string());
+                            after_val = Some(new_val);
                         }
                     }
                 }
@@ -1071,9 +1418,11 @@ impl OpenCADStudio {
                                 if before_val.is_none() {
                                     before_val = Some(base.text.clone());
                                 }
-                                base.text = new_val;
+                                if !dry_run {
+                                    base.text = new_val.clone();
+                                }
                                 entity_replaced += count;
-                                after_val = Some(base.text.clone());
+                                after_val = Some(new_val);
                             }
                         }
                     }
@@ -1085,7 +1434,9 @@ impl OpenCADStudio {
                                 matcher.replace_all_in(attr.get_value(), replacement, replace_all);
                             if count > 0 {
                                 let old_val = attr.get_value().to_string();
-                                attr.set_value(new_val.clone());
+                                if !dry_run {
+                                    attr.set_value(new_val.clone());
+                                }
                                 total_replaced += count;
                                 changes_log.push(json!({
                                     "handle": format!("{:X}", handle.value()),
@@ -1121,33 +1472,37 @@ impl OpenCADStudio {
         }
 
         if total_replaced == 0 {
-            if push_undo {
+            if push_undo && !dry_run {
                 self.discard_last_undo_entry(i);
             }
             return Ok(json!({
                 "ok": true,
+                "dry_run": dry_run,
                 "replaced": 0,
                 "entities_changed": 0,
                 "changes": [],
             }));
         }
 
-        // Refresh scene caches and dirty flags
-        self.invalidate_property_targets(i, &changed_handles);
-        self.tabs[i].scene.bump_geometry();
-        self.tabs[i].dirty = true;
-        self.refresh_properties();
+        if !dry_run {
+            // Refresh scene caches and dirty flags
+            self.invalidate_property_targets(i, &changed_handles);
+            self.tabs[i].scene.bump_geometry();
+            self.tabs[i].dirty = true;
+            self.refresh_properties();
 
-        self.command_line.push_output(
-            format!(
-                "TEXT REPLACE: replaced {total_replaced} occurrence(s) in {} object(s).",
-                changed_handles.len()
-            )
-            .as_str(),
-        );
+            self.command_line.push_output(
+                format!(
+                    "TEXT REPLACE: replaced {total_replaced} occurrence(s) in {} object(s).",
+                    changed_handles.len()
+                )
+                .as_str(),
+            );
+        }
 
         Ok(json!({
             "ok": true,
+            "dry_run": dry_run,
             "replaced": total_replaced,
             "entities_changed": changed_handles.len(),
             "changes": changes_log,
@@ -1166,6 +1521,11 @@ impl OpenCADStudio {
         self.control_text_search(req).unwrap_or_else(|e| e)
     }
 
+    /// Headless automation text audit.
+    pub(crate) fn automation_text_audit(&self, req: &Value) -> Value {
+        self.control_text_audit(req).unwrap_or_else(|e| e)
+    }
+
     /// Headless automation text replace.
     pub(crate) fn automation_text_replace(&mut self, req: &Value) -> Value {
         self.execute_text_replace(req, true).unwrap_or_else(|e| e)

src/mcp.rs

@@ -43,6 +43,7 @@ const READ_OPS: &[&str] = &[
     "xdata_get",
     "audit",
     "text_search",
+    "text_audit",
 ];
 const EXECUTE_OPS: &[&str] = &[
     "new",
@@ -1064,6 +1065,7 @@ fn execute_request_schema() -> Value {
             "match_case":{"type":"boolean","default":false,"description":"Case-sensitive text search/replace."},
             "whole_word":{"type":"boolean","default":false,"description":"Match only whole words (bounded by non-alphanumeric characters)."},
             "ignore_accents":{"type":"boolean","description":"Ignore accents/diacritics in text (defaults to true when match_case is false)."},
+            "dry_run":{"type":"boolean","default":false,"description":"When true, simulates replacement without mutating entities or pushing undo."},
             "replace_all":{"type":"boolean","default":true,"description":"Replace all occurrences within matching entities (default true)."},
             "scope":{"type":"string","enum":["all","active_space","blocks"],"default":"all","description":"Text search/replace scope."},
             "path":{"type":"string","minLength":1,"description":"Absolute path: drawing for open or save, image file for embed_image, target DWG/DXF for wblock, target PDF for plot; save_verified requires .dwg or .dxf."},
@@ -1223,7 +1225,7 @@ fn tool_definitions() -> Value {
         {
             "name":"ocs_read",
             "description":"Discover capabilities and record schemas, or read state, complete database records, command manifests, entities, properties, kernel measurements and spatial relationships, history, events or operation status from a live OCS session.",
-            "inputSchema":{"type":"object","properties":{"ocs_session_id":{"type":"string","minLength":1,"description":"Value of session_id returned by ocs_sessions."},"op":{"type":"string","enum":READ_OPS,"default":"state"},"parameters":{"type":"object","description":"Operation-specific filters.","properties":{"name":{"type":"string","description":"Command name or record name."},"search":{"type":"string","description":"Case-insensitive command or record-type search."},"find":{"type":"string","description":"Text query string for text_search."},"match_case":{"type":"boolean","default":false,"description":"Case-sensitive text search."},"whole_word":{"type":"boolean","default":false,"description":"Match only whole words."},"ignore_accents":{"type":"boolean","description":"Ignore accents/diacritics in text (defaults to true when match_case is false)."},"scope":{"type":"string","enum":["all","active_space","blocks"],"default":"all","description":"Text search scope."},"document_id":{"type":"integer","minimum":0},"path":{"type":"string","description":"Optional intended output path for audit; extension determines target format."},"target_format":{"type":"string","enum":["dwg","dxf"],"description":"Intended output format for audit."},"target_version":{"type":"string","enum":["R14","2000","2004","2007","2010","2013","2018","AC1014","AC1015","AC1018","AC1021","AC1024","AC1027","AC1032"],"description":"Intended CAD output version for audit."},"collection":{"type":"string","description":"Record collection, all for records, or omit to discover collections and schema types."},"handle":{"type":"string"},"handles":{"type":"array","items":{"type":"string"},"description":"Exact entity or record handles."},"type":{"type":"string","description":"Entity or record type filter; for record_schema, returns its complete type graph and writable field paths."},"layer":{"type":"string","description":"Layer name filter for query."},"detail":{"type":"string","enum":["summary","geometry","full"],"default":"geometry","description":"Entity detail returned by query."},"fields":{"type":"array","items":{"type":"string"},"description":"Return only these entity fields plus handle."},"paths":{"type":"array","items":{"type":"string"},"description":"Project RFC 6901 JSON Pointer paths relative to record.properties."},"where":{"type":"array","description":"All property filters must match.","items":{"type":"object","properties":{"path":{"type":"string"},"op":{"type":"string","enum":["eq","ne","lt","lte","gt","gte","contains","starts_with","ends_with","in","exists","not_exists"],"default":"eq"},"value":{}},"required":["path"],"additionalProperties":false}},"near":{"type":"array","items":{"type":"number"},"minItems":2,"maxItems":3,"description":"Rank planar curves by exact kernel distance to this world XY point."},"point":{"type":"array","items":{"type":"number"},"minItems":2,"maxItems":3,"description":"World point whose object snap the snap op reports."},"from":{"type":"array","items":{"type":"number"},"minItems":2,"maxItems":3,"description":"Base point for perpendicular and tangent snaps (snap op)."},"contains_point":{"type":"array","items":{"type":"number"},"minItems":2,"maxItems":3,"description":"Return closed planar curves containing this world XY point."},"bounds":{"type":"array","items":{"type":"number"},"minItems":4,"maxItems":4,"description":"Filter entities whose world XY bounds overlap [min_x,min_y,max_x,max_y]."},"intersections":{"type":"array","items":{"type":"string"},"minItems":2,"maxItems":2,"description":"Return exact kernel intersections between two planar curve handles."},"after":{"type":"integer","minimum":0,"description":"Event cursor."},"request_id":{"type":"string","description":"Operation id to query."},"offset":{"type":"integer","minimum":0},"limit":{"type":"integer","minimum":1,"maximum":10000}},"additionalProperties":false}},"required":["ocs_session_id"],"additionalProperties":false},
+            "inputSchema":{"type":"object","properties":{"ocs_session_id":{"type":"string","minLength":1,"description":"Value of session_id returned by ocs_sessions."},"op":{"type":"string","enum":READ_OPS,"default":"state"},"parameters":{"type":"object","description":"Operation-specific filters.","properties":{"name":{"type":"string","description":"Command name or record name."},"search":{"type":"string","description":"Case-insensitive command or record-type search."},"find":{"type":"string","description":"Text query string for text_search."},"match_case":{"type":"boolean","default":false,"description":"Case-sensitive text search."},"whole_word":{"type":"boolean","default":false,"description":"Match only whole words."},"ignore_accents":{"type":"boolean","description":"Ignore accents/diacritics in text (defaults to true when match_case is false)."},"scope":{"type":"string","enum":["all","active_space","blocks"],"default":"all","description":"Text search scope."},"check_terms":{"type":"array","items":{"type":"string"},"description":"List of terms or suspect misspellings to flag in text_audit."},"dictionary":{"type":"array","items":{"type":"string"},"description":"Known valid words for text_audit dictionary check."},"pairs":{"type":"array","description":"Find/replace pairs for dry-run simulation in text_audit.","items":{"type":"object","properties":{"find":{"type":"string"},"replace":{"type":"string"}},"required":["find","replace"]}},"dry_run_pairs":{"type":"array","description":"Alias for pairs in text_audit.","items":{"type":"object","properties":{"find":{"type":"string"},"replace":{"type":"string"}},"required":["find","replace"]}},"document_id":{"type":"integer","minimum":0},"path":{"type":"string","description":"Optional intended output path for audit; extension determines target format."},"target_format":{"type":"string","enum":["dwg","dxf"],"description":"Intended output format for audit."},"target_version":{"type":"string","enum":["R14","2000","2004","2007","2010","2013","2018","AC1014","AC1015","AC1018","AC1021","AC1024","AC1027","AC1032"],"description":"Intended CAD output version for audit."},"collection":{"type":"string","description":"Record collection, all for records, or omit to discover collections and schema types."},"handle":{"type":"string"},"handles":{"type":"array","items":{"type":"string"},"description":"Exact entity or record handles."},"type":{"type":"string","description":"Entity or record type filter; for record_schema, returns its complete type graph and writable field paths."},"layer":{"type":"string","description":"Layer name filter for query."},"detail":{"type":"string","enum":["summary","geometry","full"],"default":"geometry","description":"Entity detail returned by query."},"fields":{"type":"array","items":{"type":"string"},"description":"Return only these entity fields plus handle."},"paths":{"type":"array","items":{"type":"string"},"description":"Project RFC 6901 JSON Pointer paths relative to record.properties."},"where":{"type":"array","description":"All property filters must match.","items":{"type":"object","properties":{"path":{"type":"string"},"op":{"type":"string","enum":["eq","ne","lt","lte","gt","gte","contains","starts_with","ends_with","in","exists","not_exists"],"default":"eq"},"value":{}},"required":["path"],"additionalProperties":false}},"near":{"type":"array","items":{"type":"number"},"minItems":2,"maxItems":3,"description":"Rank planar curves by exact kernel distance to this world XY point."},"point":{"type":"array","items":{"type":"number"},"minItems":2,"maxItems":3,"description":"World point whose object snap the snap op reports."},"from":{"type":"array","items":{"type":"number"},"minItems":2,"maxItems":3,"description":"Base point for perpendicular and tangent snaps (snap op)."},"contains_point":{"type":"array","items":{"type":"number"},"minItems":2,"maxItems":3,"description":"Return closed planar curves containing this world XY point."},"bounds":{"type":"array","items":{"type":"number"},"minItems":4,"maxItems":4,"description":"Filter entities whose world XY bounds overlap [min_x,min_y,max_x,max_y]."},"intersections":{"type":"array","items":{"type":"string"},"minItems":2,"maxItems":2,"description":"Return exact kernel intersections between two planar curve handles."},"after":{"type":"integer","minimum":0,"description":"Event cursor."},"request_id":{"type":"string","description":"Operation id to query."},"offset":{"type":"integer","minimum":0},"limit":{"type":"integer","minimum":1,"maximum":10000}},"additionalProperties":false}},"required":["ocs_session_id"],"additionalProperties":false},
             "outputSchema":read_output_schema(),
             "annotations":{"title":"Read OCS state","readOnlyHint":true,"destructiveHint":false,"idempotentHint":true,"openWorldHint":false}
         },
@@ -1595,6 +1597,7 @@ mod tests {
         assert!(READ_OPS.contains(&"record_schema"));
         assert!(READ_OPS.contains(&"audit"));
         assert!(READ_OPS.contains(&"text_search"));
+        assert!(READ_OPS.contains(&"text_audit"));
         assert!(EXECUTE_OPS.contains(&"set_properties"));
         assert!(EXECUTE_OPS.contains(&"save_verified"));
         assert!(EXECUTE_OPS.contains(&"text_replace"));