diff --git a/CLAUDE.md b/CLAUDE.md
index 089018f..1f93e6f 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -30,8 +30,8 @@ tests, and this `CLAUDE.md` live in this repo's tree.
 ### Core Components
 
 1. **Protocol layer** (`src/mountainash_data/core/protocol.py`)
-   - `Backend` protocol — what every backend must implement (`connect()`)
-   - `Connection` protocol — what every connection must implement (`list_tables()`, `inspect_table()`, `to_relation()`, `close()`)
+   - `Backend` protocol — the single handle every backend must implement: `connect()`/`close()`/context-manager lifecycle, `list_tables()`/`list_namespaces()`/`list_catalogs()`, and `inspect_table()`/`inspect_namespace()`/`inspect_catalog()`
+   - There is deliberately no `to_relation()` on the protocol — bridging to the unified `mountainash` package is pull-side: `table()` returns a backend-native ibis Table and `ma.relation(ibis_table)` compiles against it directly
 
 2. **Inspection model** (`src/mountainash_data/core/inspection.py`)
    - `CatalogInfo`, `NamespaceInfo`, `TableInfo`, `ColumnInfo` — shared physical metadata dataclasses
@@ -244,7 +244,10 @@ conn = backend.connect()
 try:
     tables = conn.list_tables()
     info = conn.inspect_table("users")
-    relation = conn.to_relation("users")  # → mountainash-expressions Relation
+    ibis_table = conn.table("users")  # backend-native ibis Table
+    # Bridge to the unified mountainash package (pull-side):
+    #   import mountainash as ma
+    #   rel = ma.relation(ibis_table)  # compiles against Ibis automatically
 finally:
     conn.close()
 
diff --git a/README.md b/README.md
index 7f315c4..fb608bb 100644
--- a/README.md
+++ b/README.md
@@ -44,7 +44,10 @@ conn = backend.connect()
 try:
     tables = conn.list_tables()
     info = conn.inspect_table("my_table")
-    relation = conn.to_relation("my_table")  # → mountainash-expressions Relation
+    ibis_table = conn.table("my_table")  # backend-native ibis Table
+    # Bridge to the unified mountainash package (pull-side):
+    #   import mountainash as ma
+    #   rel = ma.relation(ibis_table)  # compiles against Ibis automatically
 finally:
     conn.close()
 
@@ -129,7 +132,7 @@ from mountainash_data import (
 
 - **12-dialect ibis registry** — SQLite, DuckDB, MotherDuck, PostgreSQL, MySQL, MSSQL, Oracle, Snowflake, BigQuery, Redshift, Trino, PySpark
 - **Protocol-first design** — `Backend` and `Connection` protocols enable type-safe composition
-- **Expressions seam** — `Connection.to_relation()` bridges to `mountainash-expressions`
+- **mountainash seam (pull-side)** — `table()` returns a backend-native ibis Table; `ma.relation(table)` in the unified `mountainash` package compiles against it directly. There is deliberately no push-side `to_relation()` bridge in this package.
 - **Settings-driven** — pydantic settings for every dialect, factory auto-detection from URLs
 - **Comprehensive test suite** ensuring reliability
 
diff --git a/src/mountainash_data/backends/iceberg/connection.py b/src/mountainash_data/backends/iceberg/connection.py
index e1720f0..ff7ec24 100644
--- a/src/mountainash_data/backends/iceberg/connection.py
+++ b/src/mountainash_data/backends/iceberg/connection.py
@@ -13,9 +13,11 @@
 - Schema caching
 - Thin delegation wrappers to ``operations.py`` for all mutations
 
-``to_relation()`` is intentionally NOT implemented — it requires
-mountainash-expressions to gain an Iceberg adapter, which is a separate
-work item tracked in the spec.
+There is deliberately no ``to_relation()`` here (or anywhere in this
+package): bridging to the unified ``mountainash`` package is pull-side —
+``ma.relation(...)`` over a backend-native handle. For Iceberg that handle
+is not an ibis Table; reaching mountainash goes via an Arrow scan of the
+loaded ``table()``, or via an Ibis engine reading the catalog.
 """
 
 from __future__ import annotations
diff --git a/tests/test_unit/backends/ibis/COVERAGE_GAP.md b/tests/test_unit/backends/ibis/COVERAGE_GAP.md
deleted file mode 100644
index 074007b..0000000
--- a/tests/test_unit/backends/ibis/COVERAGE_GAP.md
+++ /dev/null
@@ -1,27 +0,0 @@
-# Coverage Gap: to_relation() not implemented
-
-**Task 4.9 — to_relation() seam to mountainash-expressions**
-
-The `mountainash-expressions` package does not expose a `Relation.from_ibis(table)`
-API or equivalent. The `Relation` class in
-`mountainash-expressions/src/mountainash/relations/core/relation_api/relation.py`
-has no constructor that takes an ibis Table object.
-
-There is a `_from_ibis` helper in `typespec/extraction.py` but it returns a
-`TypeSpec`, not a `Relation`.
-
-**Status:** BLOCKED — to_relation() cannot be implemented without a
-`mountainash-expressions` API that creates a Relation from an ibis Table.
-
-**Resolution:** When mountainash-expressions adds `Relation.from_ibis()` or an
-equivalent, implement `IbisConnection.to_relation(table_name)` in
-`src/mountainash_data/backends/ibis/backend.py`:
-
-```python
-def to_relation(self, table_name: str, namespace: str | None = None):
-    from mountainash.relations import Relation  # adjust to actual import
-    ibis_table = self._ibis_conn.table(table_name)
-    return Relation.from_ibis(ibis_table)  # adjust to actual API
-```
-
-**Confirmed:** 2026-04-07 during Phase 4 (Task 4.9) refactor.