ocs_doc_api: Phase 2b-a (Text/MText annotations)

- CreateText/CreateMText/SetTextContent ops + GetTextContent query (append-only).
- backend add_text/add_mtext/set_text_content/text_content (Text.value/MText.value).
- facade create_text/create_mtext + Text/MText handles with content()/set_content().
- Text/MText coarse bounds + transform (insertion point); ensure_transformable.
- spec Text/MText families; api_reference + binding_schema regenerated; mocks.
- can_modify backend hook (exists + not-locked) for SetTextContent validation.
- consistency baseline extended with the appended variants.
- Test phase2b_text_mtext_create_content_transform -> 605 host lib + 3 consistency green.

crates/ocs_doc_api/IMPLEMENTATION.md

@@ -61,8 +61,12 @@ Phase 2b (annotations/hatch/dimension typed ops), attributes + nested traversal
   (Arc coarse full-circle, Ellipse major-axis radius, Spline control-point bbox;
   Ray/XLine unbounded → `Unsupported`), and transform (all five + the phase-1 set)
   via acadrust. Covered by `phase2_*` tests.
-- **Remaining (2b):** annotations `Text`/`MText` (create + content get/set), `Hatch`
-  (create + boundary query), `Dimension` (typed sub-types).
+- **Done (2b-a):** annotations `Text`/`MText` — `create_text`/`create_mtext`
+  (`CreateText`/`CreateMText` wire ops), `content()`/`set_content()` (new
+  `GetTextContent` query + `SetTextContent` op), transform (insertion point),
+  coarse bounds. Covered by `phase2b_*` test.
+- **Remaining (2b-b/c):** `Hatch` (create + boundary query), `Dimension` (typed
+  sub-types).
 - **Unblocked:** `add_vertex` (polyline) and sweep profiles (Line/Circle/Arc/LwPolyline)
   are supported (Phase 0).
 

crates/ocs_doc_api/examples/common/mod.rs

@@ -21,6 +21,8 @@ pub struct MockBackend {
     kinds: HashMap<ObjectId, String>,
     /// Stored 2D curve specs so `bounds()` works on non-solid entities too.
     curves: HashMap<ObjectId, Curve2Spec>,
+    /// Stored text content for Text/MText annotations.
+    text_values: HashMap<ObjectId, String>,
 }
 
 impl MockBackend {
@@ -133,6 +135,27 @@ impl DocApiBackend for MockBackend {
     fn add_viewport(&mut self, _spec: &ocs_doc_api::ops::ViewportSpec) -> ApiResult<ObjectId> {
         Ok(self.alloc("Viewport"))
     }
+    fn add_text(&mut self, spec: &ocs_doc_api::ops::TextSpec) -> ApiResult<ObjectId> {
+        let id = self.alloc("Text");
+        self.text_values.insert(id, spec.value.clone());
+        Ok(id)
+    }
+    fn add_mtext(&mut self, spec: &ocs_doc_api::ops::MTextSpec) -> ApiResult<ObjectId> {
+        let id = self.alloc("MText");
+        self.text_values.insert(id, spec.value.clone());
+        Ok(id)
+    }
+    fn set_text_content(&mut self, id: ObjectId, value: &str) -> ApiResult<()> {
+        if let std::collections::hash_map::Entry::Occupied(mut e) = self.text_values.entry(id) {
+            e.insert(value.to_string());
+            Ok(())
+        } else {
+            Err(ApiError::UnknownId(id))
+        }
+    }
+    fn text_content(&self, id: ObjectId) -> ApiResult<String> {
+        self.text_values.get(&id).cloned().ok_or(ApiError::UnknownId(id))
+    }
     fn add_vertex(&mut self, id: ObjectId, _at: usize, _point: [f64; 3]) -> ApiResult<()> {
         if self.entity_exists(id) {
             Ok(())

crates/ocs_doc_api/spec/entities.toml

@@ -237,6 +237,59 @@ args = [{ name = "origin", ty = "[f64; 3]" }, { name = "direction", ty = "[f64;
 op = "CreateCurve"
 fixed = { curve = "XLine" }
 
+# ============================================================================
+# ANNOTATION FAMILY (phase 2b) — text annotations
+# ============================================================================
+[[family]]
+name = "Text"
+acadrust_variant = "Text"
+handle = "Text"
+collection = "curves"
+description = "Single-line text annotation. content()/set_content() read+replace the value; transform moves insertion point."
+
+[[family.constructor]]
+name = "create_text"
+args = [{ name = "value", ty = "&str" }, { name = "insertion_point", ty = "[f64; 3]" }, { name = "height", ty = "f64" }, { name = "rotation", ty = "f64" }]
+op = "CreateText"
+
+[[family.method]]
+name = "content"
+kind = "query"
+query = "GetTextContent"
+returns = "String"
+
+[[family.method]]
+name = "set_content"
+kind = "op"
+op = "SetTextContent"
+args = [{ name = "value", ty = "&str" }]
+returns = "()"
+
+[[family]]
+name = "MText"
+acadrust_variant = "MText"
+handle = "MText"
+collection = "curves"
+description = "Multi-line text annotation. content()/set_content() read+replace the value; transform moves insertion point."
+
+[[family.constructor]]
+name = "create_mtext"
+args = [{ name = "value", ty = "&str" }, { name = "insertion_point", ty = "[f64; 3]" }, { name = "height", ty = "f64" }]
+op = "CreateMText"
+
+[[family.method]]
+name = "content"
+kind = "query"
+query = "GetTextContent"
+returns = "String"
+
+[[family.method]]
+name = "set_content"
+kind = "op"
+op = "SetTextContent"
+args = [{ name = "value", ty = "&str" }]
+returns = "()"
+
 # ============================================================================
 # CONTAINER FAMILY (phase 3) — block references
 # ============================================================================

crates/ocs_doc_api/src/backend.rs

@@ -42,6 +42,29 @@ pub trait DocApiBackend {
     /// Add a paper-space `VIEWPORT`; returns the fresh `ObjectId`.
     fn add_viewport(&mut self, spec: &crate::ops::ViewportSpec) -> ApiResult<ObjectId>;
 
+    /// Add a single-line `TEXT` annotation; returns the fresh `ObjectId`.
+    fn add_text(&mut self, spec: &crate::ops::TextSpec) -> ApiResult<ObjectId>;
+
+    /// Add a multi-line `MTEXT` annotation; returns the fresh `ObjectId`.
+    fn add_mtext(&mut self, spec: &crate::ops::MTextSpec) -> ApiResult<ObjectId>;
+
+    /// Set the text content of a Text/MText annotation in place.
+    fn set_text_content(&mut self, id: ObjectId, value: &str) -> ApiResult<()>;
+
+    /// The text content of a Text/MText annotation. `Unsupported` for other kinds.
+    fn text_content(&self, id: ObjectId) -> ApiResult<String>;
+
+    /// Can `id` be modified in place right now (exists, is the expected family,
+    /// not on a locked layer)? Read-only pre-check used before mutations.
+    /// Default: existence + not-locked (backends narrow the family check).
+    fn can_modify(&self, id: ObjectId) -> ApiResult<()> {
+        if self.entity_exists(id) {
+            Ok(())
+        } else {
+            Err(ApiError::UnknownId(id))
+        }
+    }
+
     /// Remove any first-level entity by id. Returns `false` if absent; returns
     /// `Err` if the entity exists but cannot be removed (e.g. locked layer).
     fn remove_entity(&mut self, id: ObjectId) -> ApiResult<bool>;

crates/ocs_doc_api/src/executor.rs

@@ -189,6 +189,28 @@ pub fn apply_op<B: DocApiBackend>(b: &mut B, op: Operation) -> ApiResult<Receipt
             b.finalize_op();
             OpOutcome::NewId(id)
         }
+        Operation::CreateText(spec) => {
+            b.push_undo(name);
+            let id = b.add_text(spec)?;
+            b.finalize_op();
+            OpOutcome::NewId(id)
+        }
+        Operation::CreateMText(spec) => {
+            b.push_undo(name);
+            let id = b.add_mtext(spec)?;
+            b.finalize_op();
+            OpOutcome::NewId(id)
+        }
+        Operation::SetTextContent { id, value } => {
+            b.can_modify(*id).map_err(|e| match e {
+                ApiError::UnknownId(_) => ApiError::validation(name, format!("unknown ObjectId {id:?}")),
+                other => other,
+            })?;
+            b.push_undo(name);
+            b.set_text_content(*id, value)?;
+            b.finalize_op();
+            OpOutcome::Updated(*id)
+        }
     };
     Ok(Receipt {
         outcome: Some(outcome),
@@ -226,6 +248,7 @@ pub fn apply_queries<B: DocApiBackend>(b: &mut B, queries: Vec<Query>) -> ApiRes
                 QueryResult::Intersects(ba.overlaps(&bb))
             }
             Query::GetGeometryRevision => QueryResult::Revision(b.revision()),
+            Query::GetTextContent { id } => QueryResult::TextContent(b.text_content(id)?),
         };
         results.push(r);
     }

crates/ocs_doc_api/src/facade.rs

@@ -267,6 +267,8 @@ handle!(Ellipse);
 handle!(Spline);
 handle!(Ray);
 handle!(XLine);
+handle!(Text);
+handle!(MText);
 
 impl Entity {
     pub fn view(&self) -> ApiResult<EntityView> {
@@ -331,6 +333,27 @@ impl Polyline {
     }
 }
 
+macro_rules! text_handle {
+    ($name:ident) => {
+        impl $name {
+            /// The text content of this annotation.
+            pub fn content(&self) -> ApiResult<String> {
+                match self.session.one_query(Query::GetTextContent { id: self.id })? {
+                    QueryResult::TextContent(s) => Ok(s),
+                    _ => Err(ApiError::Transport("unexpected content result".into())),
+                }
+            }
+            /// Replace the text content (one undo step).
+            pub fn set_content(&self, value: &str) -> ApiResult<()> {
+                self.session.apply_op(Operation::SetTextContent { id: self.id, value: value.to_string() })?;
+                Ok(())
+            }
+        }
+    };
+}
+text_handle!(Text);
+text_handle!(MText);
+
 // ── Collections (construction / lookup) ─────────────────────────────────────
 
 #[derive(Clone)]
@@ -442,6 +465,27 @@ impl CurveCollection {
         let (s, id) = self.create_curve(Curve2Spec::XLine { origin, direction })?;
         Ok(XLine::new(s, id))
     }
+    /// Single-line TEXT annotation.
+    pub fn create_text(&self, value: &str, insertion_point: [f64; 3], height: f64, rotation: f64) -> ApiResult<Text> {
+        let receipt = self.session.apply_op(Operation::CreateText(crate::ops::TextSpec {
+            value: value.to_string(),
+            insertion_point,
+            height,
+            rotation,
+        }))?;
+        let id = receipt.outcome.and_then(|o| o.new_id()).ok_or_else(|| ApiError::Transport("create_text returned no id".into()))?;
+        Ok(Text::new(self.session.clone(), id))
+    }
+    /// Multi-line MTEXT annotation.
+    pub fn create_mtext(&self, value: &str, insertion_point: [f64; 3], height: f64) -> ApiResult<MText> {
+        let receipt = self.session.apply_op(Operation::CreateMText(crate::ops::MTextSpec {
+            value: value.to_string(),
+            insertion_point,
+            height,
+        }))?;
+        let id = receipt.outcome.and_then(|o| o.new_id()).ok_or_else(|| ApiError::Transport("create_mtext returned no id".into()))?;
+        Ok(MText::new(self.session.clone(), id))
+    }
     /// Bulk-create many points in ONE op (plan §5.3): all-or-nothing, one undo step.
     pub fn create_points(&self, positions: &[[f64; 3]]) -> ApiResult<Vec<Point>> {
         let specs: Vec<crate::ops::EntitySpec> = positions

crates/ocs_doc_api/src/gen/api_reference.md

@@ -87,6 +87,32 @@ B-rep solid. Host resolves bodies via the solid_models cache (lift-on-miss from
 
 - **create_xline**(`origin: [f64; 3], direction: [f64; 3]`) -> `XLine`
 
+## `Text` (acadrust `Text`, collection `curves`)
+
+Single-line text annotation. content()/set_content() read+replace the value; transform moves insertion point.
+
+### Constructors (`doc.curves()`)
+
+- **create_text**(`value: &str, insertion_point: [f64; 3], height: f64, rotation: f64`) -> `Text`
+
+### Methods
+
+- **content**(``) -> `String` — query `GetTextContent`
+- **set_content**(`value: &str`) -> `()` — op `SetTextContent`
+
+## `MText` (acadrust `MText`, collection `curves`)
+
+Multi-line text annotation. content()/set_content() read+replace the value; transform moves insertion point.
+
+### Constructors (`doc.curves()`)
+
+- **create_mtext**(`value: &str, insertion_point: [f64; 3], height: f64`) -> `MText`
+
+### Methods
+
+- **content**(``) -> `String` — query `GetTextContent`
+- **set_content**(`value: &str`) -> `()` — op `SetTextContent`
+
 ## `Entity` (acadrust `Insert`, collection `entities`)
 
 Block reference. Place an existing BlockRecord by name; transform moves its insert point.

crates/ocs_doc_api/src/gen/binding_schema.json

@@ -188,6 +188,76 @@
       "methods": [],
       "name": "XLine"
     },
+    {
+      "acadrust_variant": "Text",
+      "collection": "curves",
+      "handle": "Text",
+      "methods": [
+        {
+          "args": [],
+          "bulk": false,
+          "fixed": null,
+          "kind": "query",
+          "name": "content",
+          "op": null,
+          "query": "GetTextContent",
+          "read_only": true,
+          "returns": "String"
+        },
+        {
+          "args": [
+            {
+              "name": "value",
+              "ty": "&str"
+            }
+          ],
+          "bulk": false,
+          "fixed": null,
+          "kind": "op",
+          "name": "set_content",
+          "op": "SetTextContent",
+          "query": null,
+          "read_only": false,
+          "returns": "()"
+        }
+      ],
+      "name": "Text"
+    },
+    {
+      "acadrust_variant": "MText",
+      "collection": "curves",
+      "handle": "MText",
+      "methods": [
+        {
+          "args": [],
+          "bulk": false,
+          "fixed": null,
+          "kind": "query",
+          "name": "content",
+          "op": null,
+          "query": "GetTextContent",
+          "read_only": true,
+          "returns": "String"
+        },
+        {
+          "args": [
+            {
+              "name": "value",
+              "ty": "&str"
+            }
+          ],
+          "bulk": false,
+          "fixed": null,
+          "kind": "op",
+          "name": "set_content",
+          "op": "SetTextContent",
+          "query": null,
+          "read_only": false,
+          "returns": "()"
+        }
+      ],
+      "name": "MText"
+    },
     {
       "acadrust_variant": "Insert",
       "collection": "entities",
@@ -270,7 +340,9 @@
       "Ellipse",
       "Spline",
       "Ray",
-      "XLine"
+      "XLine",
+      "Text",
+      "MText"
     ],
     "root": "DocApi"
   },

crates/ocs_doc_api/src/gen/ops_gen.rs

@@ -7,7 +7,7 @@
 use serde::{Deserialize, Serialize};
 
 use crate::id::ObjectId;
-use crate::ops::{BoolOp, Curve2Spec, EntitySpec, InsertSpec, PlacementSpec, SolidPrimitive, ViewportSpec};
+use crate::ops::{BoolOp, Curve2Spec, EntitySpec, InsertSpec, MTextSpec, PlacementSpec, SolidPrimitive, TextSpec, ViewportSpec};
 
 /// A typed write operation (plan §5). Each variant is ONE atomic host call = one
 /// undo step. Append new variants at the END only.
@@ -32,4 +32,8 @@ pub enum Operation {
     CreateInsert(InsertSpec),
     // paper-space
     CreateViewport(ViewportSpec),
+    // annotations
+    CreateText(TextSpec),
+    CreateMText(MTextSpec),
+    SetTextContent { id: ObjectId, value: String },
 }

crates/ocs_doc_api/src/gen/query_gen.rs

@@ -19,4 +19,6 @@ pub enum Query {
     /// Whether two entities' bounds overlap (two-phase conditional modelling).
     GetIntersects { a: ObjectId, b: ObjectId },
     GetGeometryRevision,
+    /// The text content of a Text/MText annotation.
+    GetTextContent { id: ObjectId },
 }

crates/ocs_doc_api/src/ops.rs

@@ -79,6 +79,23 @@ pub struct ViewportSpec {
     pub view_height: f64,
 }
 
+/// Construction spec for a single-line `TEXT` annotation.
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub struct TextSpec {
+    pub value: String,
+    pub insertion_point: [f64; 3],
+    pub height: f64,
+    pub rotation: f64,
+}
+
+/// Construction spec for a multi-line `MTEXT` annotation.
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub struct MTextSpec {
+    pub value: String,
+    pub insertion_point: [f64; 3],
+    pub height: f64,
+}
+
 /// A rigid similarity (rotation + translation + optional uniform scale/reflection)
 /// as a plain-data mirror of `cadkernel::brep::transform`'s `Placement`
 /// (non-serde). Columns are the new basis axes; `origin` is the translation.
@@ -128,6 +145,9 @@ impl crate::gen::Operation {
             DeleteMany(_) => "DeleteMany",
             CreateInsert(_) => "CreateInsert",
             CreateViewport(_) => "CreateViewport",
+            CreateText(_) => "CreateText",
+            CreateMText(_) => "CreateMText",
+            SetTextContent { .. } => "SetTextContent",
         }
     }
 }

crates/ocs_doc_api/src/query.rs

@@ -43,6 +43,8 @@ pub enum QueryResult {
     /// Whether two entities' bounds overlap (two-phase conditional modelling).
     Intersects(bool),
     Revision(GeometryRevision),
+    /// The text content of a Text/MText annotation.
+    TextContent(String),
 }
 
 /// Convenience: the query name for diagnostics.
@@ -56,6 +58,7 @@ impl crate::gen::Query {
             GetVolume { .. } => "GetVolume",
             GetIntersects { .. } => "GetIntersects",
             GetGeometryRevision => "GetGeometryRevision",
+            GetTextContent { .. } => "GetTextContent",
         }
     }
 }

crates/ocs_doc_api/tests/mock_backend.rs

@@ -21,6 +21,8 @@ struct MockBackend {
     undo_steps: u32,
     bodies: HashMap<ObjectId, KernelBody>,
     kinds: HashMap<ObjectId, String>,
+    /// Stored text content for Text/MText annotations.
+    text_values: HashMap<ObjectId, String>,
 }
 
 impl MockBackend {
@@ -73,6 +75,27 @@ impl DocApiBackend for MockBackend {
     fn add_viewport(&mut self, _spec: &ocs_doc_api::ops::ViewportSpec) -> ApiResult<ObjectId> {
         Ok(self.alloc("Viewport"))
     }
+    fn add_text(&mut self, spec: &ocs_doc_api::ops::TextSpec) -> ApiResult<ObjectId> {
+        let id = self.alloc("Text");
+        self.text_values.insert(id, spec.value.clone());
+        Ok(id)
+    }
+    fn add_mtext(&mut self, spec: &ocs_doc_api::ops::MTextSpec) -> ApiResult<ObjectId> {
+        let id = self.alloc("MText");
+        self.text_values.insert(id, spec.value.clone());
+        Ok(id)
+    }
+    fn set_text_content(&mut self, id: ObjectId, value: &str) -> ApiResult<()> {
+        if let std::collections::hash_map::Entry::Occupied(mut e) = self.text_values.entry(id) {
+            e.insert(value.to_string());
+            Ok(())
+        } else {
+            Err(ApiError::UnknownId(id))
+        }
+    }
+    fn text_content(&self, id: ObjectId) -> ApiResult<String> {
+        self.text_values.get(&id).cloned().ok_or(ApiError::UnknownId(id))
+    }
     fn add_vertex(&mut self, id: ObjectId, _at: usize, _point: [f64; 3]) -> ApiResult<()> {
         if self.entity_exists(id) {
             Ok(())

crates/ocs_doc_api/tests/spec_wire_consistency.rs

@@ -53,6 +53,9 @@ fn operation_variants() -> Vec<String> {
         Operation::DeleteMany(vec![]),
         Operation::CreateInsert(InsertSpec { block_name: String::new(), insert_point: [0.0; 3], scale: 1.0, rotation: 0.0 }),
         Operation::CreateViewport(ViewportSpec { center: [0.0; 3], width: 0.0, height: 0.0, view_target: [0.0; 3], view_height: 0.0 }),
+        Operation::CreateText(ocs_doc_api::ops::TextSpec { value: String::new(), insertion_point: [0.0; 3], height: 0.0, rotation: 0.0 }),
+        Operation::CreateMText(ocs_doc_api::ops::MTextSpec { value: String::new(), insertion_point: [0.0; 3], height: 0.0 }),
+        Operation::SetTextContent { id: ObjectId::from_u64(0), value: String::new() },
     ];
     // Derive the variant names by serializing a probe of each and reading the
     // bincode variant index -> name map is not available; instead match by
@@ -77,6 +80,7 @@ fn query_variants() -> Vec<String> {
         Query::GetVolume { id: ObjectId::from_u64(0) },
         Query::GetIntersects { a: ObjectId::from_u64(0), b: ObjectId::from_u64(0) },
         Query::GetGeometryRevision,
+        Query::GetTextContent { id: ObjectId::from_u64(0) },
     ];
     marker
         .iter()
@@ -127,6 +131,9 @@ const OPERATION_BASELINE: &[&str] = &[
     "DeleteMany",
     "CreateInsert",
     "CreateViewport",
+    "CreateText",
+    "CreateMText",
+    "SetTextContent",
 ];
 
 /// Recorded baseline of the `Query` variant order.
@@ -137,6 +144,7 @@ const QUERY_BASELINE: &[&str] = &[
     "GetVolume",
     "GetIntersects",
     "GetGeometryRevision",
+    "GetTextContent",
 ];
 
 #[test]

src/app/doc_api.rs

@@ -139,6 +139,64 @@ impl DocApiBackend for HostSession<'_> {
         Ok(handle_to_obj(handle))
     }
 
+    fn add_text(&mut self, spec: &ocs_doc_api::ops::TextSpec) -> ApiResult<ObjectId> {
+        use acadrust::entities::Text;
+        use acadrust::types::Vector3;
+        let mut t = Text::new();
+        t.value = spec.value.clone();
+        t.insertion_point = Vector3::new(spec.insertion_point[0], spec.insertion_point[1], spec.insertion_point[2]);
+        t.height = spec.height;
+        t.rotation = spec.rotation;
+        let handle = self.scene_mut().add_entity(EntityType::Text(t));
+        Ok(handle_to_obj(handle))
+    }
+
+    fn add_mtext(&mut self, spec: &ocs_doc_api::ops::MTextSpec) -> ApiResult<ObjectId> {
+        use acadrust::entities::MText;
+        use acadrust::types::Vector3;
+        let mut t = MText::with_value(
+            spec.value.clone(),
+            Vector3::new(spec.insertion_point[0], spec.insertion_point[1], spec.insertion_point[2]),
+        );
+        t.height = spec.height;
+        let handle = self.scene_mut().add_entity(EntityType::MText(t));
+        Ok(handle_to_obj(handle))
+    }
+
+    fn set_text_content(&mut self, id: ObjectId, value: &str) -> ApiResult<()> {
+        let handle = obj_to_handle(id);
+        let entity = self.document().get_entity(handle).cloned().ok_or(ApiError::UnknownId(id))?;
+        let new_entity = match entity {
+            EntityType::Text(mut t) => { t.value = value.to_string(); EntityType::Text(t) }
+            EntityType::MText(mut t) => { t.value = value.to_string(); EntityType::MText(t) }
+            _ => return Err(ApiError::Unsupported("SetTextContent is only for Text/MText".into())),
+        };
+        if !self.scene_mut().update_entity(new_entity) {
+            return Err(ApiError::Unsupported(format!("entity {id:?} is on a locked layer")));
+        }
+        Ok(())
+    }
+
+    fn text_content(&self, id: ObjectId) -> ApiResult<String> {
+        let entity = self.document().get_entity(obj_to_handle(id)).ok_or(ApiError::UnknownId(id))?;
+        match entity {
+            EntityType::Text(t) => Ok(t.value.clone()),
+            EntityType::MText(t) => Ok(t.value.clone()),
+            _ => Err(ApiError::Unsupported("GetTextContent is only for Text/MText".into())),
+        }
+    }
+
+    fn can_modify(&self, id: ObjectId) -> ApiResult<()> {
+        let handle = obj_to_handle(id);
+        if !self.entity_exists(id) {
+            return Err(ApiError::UnknownId(id));
+        }
+        if self.scene().is_layer_locked(handle) {
+            return Err(ApiError::Unsupported(format!("entity {id:?} is on a locked layer")));
+        }
+        Ok(())
+    }
+
     fn add_vertex(&mut self, id: ObjectId, at: usize, point: [f64; 3]) -> ApiResult<()> {
         let handle = obj_to_handle(id);
         let Some(entity) = self.document().get_entity(handle).cloned() else {
@@ -201,6 +259,8 @@ impl DocApiBackend for HostSession<'_> {
                 | EntityType::XLine(_)
                 | EntityType::Insert(_)
                 | EntityType::Viewport(_)
+                | EntityType::Text(_)
+                | EntityType::MText(_)
                 | EntityType::Point(_)
                 | EntityType::LwPolyline(_)
         );
@@ -766,6 +826,44 @@ mod tests {
         assert_eq!(host.scene().geometry_epoch, rev_before, "no mutation on rejected TransformMany");
     }
 
+    // ── Phase 2b-a: annotations (Text/MText) ─────────────────────────────────
+
+    #[test]
+    fn phase2b_text_mtext_create_content_transform() {
+        let mut app = OpenCADStudio::new_for_test();
+        let mut host = HostSession::new(&mut app, 0);
+
+        // Create a TEXT, read its content, set it, verify.
+        let text = new_id(&dispatch(&mut host, DocApiEnvelope::op(Operation::CreateText(
+            ocs_doc_api::ops::TextSpec { value: "hello".into(), insertion_point: [1.0, 2.0, 0.0], height: 2.5, rotation: 0.0 }))).unwrap());
+        let receipt = dispatch(&mut host, DocApiEnvelope::queries(vec![Query::GetTextContent { id: text }])).unwrap();
+        match &receipt.query_results[0] {
+            QueryResult::TextContent(s) => assert_eq!(s, "hello"),
+            other => panic!("expected content, got {other:?}"),
+        }
+        dispatch(&mut host, DocApiEnvelope::op(Operation::SetTextContent { id: text, value: "world".into() })).unwrap();
+        let Some(EntityType::Text(t)) = host.document().get_entity(obj_to_handle(text)) else { panic!("text not found") };
+        assert_eq!(t.value, "world");
+
+        // SetTextContent on a non-text entity is Unsupported.
+        let line = new_id(&dispatch(&mut host, DocApiEnvelope::op(Operation::CreateCurve(
+            Curve2Spec::Line { start: [0.0; 3], end: [1.0; 3] }))).unwrap());
+        assert!(dispatch(&mut host, DocApiEnvelope::op(Operation::SetTextContent { id: line, value: "x".into() })).is_err());
+
+        // MTEXT create + content + transform (insertion point moves).
+        let mtext = new_id(&dispatch(&mut host, DocApiEnvelope::op(Operation::CreateMText(
+            ocs_doc_api::ops::MTextSpec { value: "multi\nline".into(), insertion_point: [5.0, 5.0, 0.0], height: 3.0 }))).unwrap());
+        let receipt = dispatch(&mut host, DocApiEnvelope::queries(vec![Query::GetTextContent { id: mtext }])).unwrap();
+        match &receipt.query_results[0] {
+            QueryResult::TextContent(s) => assert_eq!(s, "multi\nline"),
+            other => panic!("expected content, got {other:?}"),
+        }
+        dispatch(&mut host, DocApiEnvelope::op(Operation::Transform {
+            id: mtext, placement: ocs_doc_api::PlacementSpec::at([10.0, 0.0, 0.0]) })).unwrap();
+        let Some(EntityType::MText(t)) = host.document().get_entity(obj_to_handle(mtext)) else { panic!("mtext not found") };
+        assert!((t.insertion_point.x - 15.0).abs() < 1e-6);
+    }
+
     // ── Phase 5: media & misc (read-mostly) ──────────────────────────────────
 
     #[test]

src/app/doc_api_convert.rs

@@ -155,6 +155,16 @@ pub fn transform_entity_geometry(
             vp.center = apply(vp.center);
             EntityType::Viewport(vp)
         }
+        EntityType::Text(t) => {
+            let mut t = t.clone();
+            t.insertion_point = apply(t.insertion_point);
+            EntityType::Text(t)
+        }
+        EntityType::MText(t) => {
+            let mut t = t.clone();
+            t.insertion_point = apply(t.insertion_point);
+            EntityType::MText(t)
+        }
         EntityType::Point(pt) => {
             let mut pt = pt.clone();
             pt.location = apply(pt.location);
@@ -393,6 +403,15 @@ pub fn entity_bounds(entity: Option<&EntityType>, id: ObjectId) -> ApiResult<Aab
                 max: [max_x, max_y, img.insertion_point.z],
             }
         }
+        EntityType::Text(t) => Aabb {
+            // Coarse: a square of side height*N around the insertion point.
+            min: [t.insertion_point.x, t.insertion_point.y - t.height, t.insertion_point.z],
+            max: [t.insertion_point.x + t.height * t.value.len() as f64, t.insertion_point.y, t.insertion_point.z],
+        },
+        EntityType::MText(t) => Aabb {
+            min: [t.insertion_point.x, t.insertion_point.y - t.height, t.insertion_point.z],
+            max: [t.insertion_point.x + t.height * t.value.len() as f64, t.insertion_point.y, t.insertion_point.z],
+        },
         // Ray/XLine are unbounded by definition — no finite bounds.
         _ => return Err(ApiError::Unsupported("bounds for this entity family is not yet implemented".into())),
     };