chore: bump version to 1.4.1 and update changelog

Document the reference column filter support feature.

CHANGELOG.md

@@ -5,6 +5,63 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [1.4.1] - 2026-01-14
+
+### Added
+
+#### Reference Column Filter Support
+- **Filter normalization**: `get_records` now automatically normalizes filter values to array format
+- Fixes 400 errors when filtering on `Ref:*` (reference/foreign key) columns
+- Single values are wrapped in arrays before sending to Grist API
+
+#### Usage
+```python
+# Before: Failed with 400 Bad Request
+get_records(document="accounting", table="TransactionLines", filter={"Transaction": 44})
+
+# After: Works - filter normalized to {"Transaction": [44]}
+get_records(document="accounting", table="TransactionLines", filter={"Transaction": 44})
+
+# Multiple values also supported
+get_records(document="accounting", table="TransactionLines", filter={"Transaction": [44, 45, 46]})
+```
+
+### Fixed
+- Shell script shebangs updated to `#!/usr/bin/env bash` for portability across environments
+
+## [1.4.0] - 2026-01-12
+
+### Added
+
+#### Attachment Download via Proxy
+- **`GET /api/v1/attachments/{id}`**: New HTTP endpoint for downloading attachments
+- Returns binary content with appropriate `Content-Type` and `Content-Disposition` headers
+- Requires read permission in session token
+- Complements the existing upload endpoint for complete attachment workflows
+
+#### Usage
+```bash
+# Get session token with read permission
+TOKEN=$(curl -s ... | jq -r '.token')
+
+# Download attachment
+curl -H "Authorization: Bearer $TOKEN" \
+  https://example.com/api/v1/attachments/42 \
+  -o downloaded.pdf
+```
+
+```python
+# Python example
+import requests
+
+response = requests.get(
+    f'{base_url}/api/v1/attachments/42',
+    headers={'Authorization': f'Bearer {token}'}
+)
+with open('downloaded.pdf', 'wb') as f:
+    f.write(response.content)
+```
+
 ## [1.3.0] - 2026-01-03
 
 ### Added

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "grist-mcp"
-version = "1.3.0"
+version = "1.4.1"
 description = "MCP server for AI agents to interact with Grist documents"
 requires-python = ">=3.14"
 dependencies = [

scripts/get-test-instance-id.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 # scripts/get-test-instance-id.sh
 # Generate a unique instance ID from git branch for parallel test isolation
 

scripts/run-integration-tests.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 # scripts/run-integration-tests.sh
 # Run integration tests with branch isolation and dynamic port discovery
 set -e

src/grist_mcp/grist_client.py

@@ -149,6 +149,38 @@ class GristClient:
                 "size_bytes": len(content),
             }
 
+    async def download_attachment(self, attachment_id: int) -> dict:
+        """Download an attachment by ID.
+
+        Args:
+            attachment_id: The ID of the attachment to download.
+
+        Returns:
+            Dict with content (bytes), content_type, and filename.
+        """
+        import re
+
+        async with httpx.AsyncClient(timeout=self._timeout) as client:
+            response = await client.get(
+                f"{self._base_url}/attachments/{attachment_id}/download",
+                headers=self._headers,
+            )
+            response.raise_for_status()
+
+            # Extract filename from Content-Disposition header
+            content_disp = response.headers.get("content-disposition", "")
+            filename = None
+            if "filename=" in content_disp:
+                match = re.search(r'filename="?([^";]+)"?', content_disp)
+                if match:
+                    filename = match.group(1)
+
+            return {
+                "content": response.content,
+                "content_type": response.headers.get("content-type", "application/octet-stream"),
+                "filename": filename,
+            }
+
     # Schema operations
 
     async def create_table(self, table_id: str, columns: list[dict]) -> str:

src/grist_mcp/main.py

@@ -363,6 +363,67 @@ def create_app(config: Config):
                 "code": "GRIST_ERROR",
             })
 
+    async def handle_attachment_download(
+        scope: Scope, receive: Receive, send: Send, attachment_id: int
+    ) -> None:
+        """Handle attachment download by ID."""
+        # Extract token
+        token = _get_bearer_token(scope)
+        if not token:
+            await send_json_response(send, 401, {
+                "success": False,
+                "error": "Missing Authorization header",
+                "code": "INVALID_TOKEN",
+            })
+            return
+
+        # Validate session token
+        session = token_manager.validate_token(token)
+        if session is None:
+            await send_json_response(send, 401, {
+                "success": False,
+                "error": "Invalid or expired token",
+                "code": "TOKEN_EXPIRED",
+            })
+            return
+
+        # Check read permission
+        if "read" not in session.permissions:
+            await send_json_response(send, 403, {
+                "success": False,
+                "error": "Read permission required for attachment download",
+                "code": "UNAUTHORIZED",
+            })
+            return
+
+        # Download from Grist
+        try:
+            doc = auth.get_document(session.document)
+            client = GristClient(doc)
+            result = await client.download_attachment(attachment_id)
+
+            # Build response headers
+            headers = [[b"content-type", result["content_type"].encode()]]
+            if result["filename"]:
+                disposition = f'attachment; filename="{result["filename"]}"'
+                headers.append([b"content-disposition", disposition.encode()])
+
+            await send({
+                "type": "http.response.start",
+                "status": 200,
+                "headers": headers,
+            })
+            await send({
+                "type": "http.response.body",
+                "body": result["content"],
+            })
+        except Exception as e:
+            await send_json_response(send, 500, {
+                "success": False,
+                "error": str(e),
+                "code": "GRIST_ERROR",
+            })
+
     async def app(scope: Scope, receive: Receive, send: Send) -> None:
         if scope["type"] != "http":
             return
@@ -380,6 +441,17 @@ def create_app(config: Config):
             await handle_proxy(scope, receive, send)
         elif path == "/api/v1/attachments" and method == "POST":
             await handle_attachments(scope, receive, send)
+        elif path.startswith("/api/v1/attachments/") and method == "GET":
+            # Parse attachment ID from path: /api/v1/attachments/{id}
+            try:
+                attachment_id = int(path.split("/")[-1])
+                await handle_attachment_download(scope, receive, send, attachment_id)
+            except ValueError:
+                await send_json_response(send, 400, {
+                    "success": False,
+                    "error": "Invalid attachment ID",
+                    "code": "INVALID_REQUEST",
+                })
         else:
             await handle_not_found(scope, receive, send)
 

src/grist_mcp/tools/filters.py

@@ -0,0 +1,37 @@
+"""Filter normalization for Grist API queries."""
+
+from typing import Any
+
+
+def normalize_filter_value(value: Any) -> list:
+    """Ensure a filter value is a list.
+
+    Grist API expects filter values to be arrays.
+
+    Args:
+        value: Single value or list of values.
+
+    Returns:
+        Value wrapped in list, or original list if already a list.
+    """
+    if isinstance(value, list):
+        return value
+    return [value]
+
+
+def normalize_filter(filter: dict | None) -> dict | None:
+    """Normalize filter values to array format for Grist API.
+
+    Grist expects all filter values to be arrays. This function
+    wraps single values in lists.
+
+    Args:
+        filter: Filter dict with column names as keys.
+
+    Returns:
+        Normalized filter dict, or None if input was None.
+    """
+    if not filter:
+        return filter
+
+    return {key: normalize_filter_value(value) for key, value in filter.items()}

src/grist_mcp/tools/read.py

@@ -2,6 +2,7 @@
 
 from grist_mcp.auth import Agent, Authenticator, Permission
 from grist_mcp.grist_client import GristClient
+from grist_mcp.tools.filters import normalize_filter
 
 
 async def list_tables(
@@ -56,7 +57,10 @@ async def get_records(
         doc = auth.get_document(document)
         client = GristClient(doc)
 
-    records = await client.get_records(table, filter=filter, sort=sort, limit=limit)
+    # Normalize filter values to array format for Grist API
+    normalized_filter = normalize_filter(filter)
+
+    records = await client.get_records(table, filter=normalized_filter, sort=sort, limit=limit)
     return {"records": records}
 
 

src/grist_mcp/tools/session.py

@@ -8,9 +8,10 @@ PROXY_DOCUMENTATION = {
     "description": "HTTP proxy API for bulk data operations. Use request_session_token to get a short-lived token, then call the proxy endpoint directly from scripts.",
     "endpoints": {
         "proxy": "POST /api/v1/proxy - JSON operations (CRUD, schema)",
-        "attachments": "POST /api/v1/attachments - File uploads (multipart/form-data)",
+        "attachments_upload": "POST /api/v1/attachments - File uploads (multipart/form-data)",
+        "attachments_download": "GET /api/v1/attachments/{id} - File downloads (binary response)",
     },
-    "endpoint_note": "The full URL is returned in the 'proxy_url' field of request_session_token response. Replace /proxy with /attachments for file uploads.",
+    "endpoint_note": "The full URL is returned in the 'proxy_url' field of request_session_token response. Replace /proxy with /attachments for file operations.",
     "authentication": "Bearer token in Authorization header",
     "attachment_upload": {
         "endpoint": "POST /api/v1/attachments",
@@ -27,6 +28,20 @@ response = requests.post(
 )
 attachment_id = response.json()['data']['attachment_id']
 # Link to record: update_records with {'Attachment': [attachment_id]}""",
+    },
+    "attachment_download": {
+        "endpoint": "GET /api/v1/attachments/{attachment_id}",
+        "permission": "read",
+        "description": "Download attachment by ID. Returns binary content with appropriate Content-Type and Content-Disposition headers.",
+        "response_headers": ["Content-Type", "Content-Disposition"],
+        "example_curl": "curl -H 'Authorization: Bearer TOKEN' URL/api/v1/attachments/42 -o file.pdf",
+        "example_python": """import requests
+response = requests.get(
+    f'{base_url}/api/v1/attachments/42',
+    headers={'Authorization': f'Bearer {token}'}
+)
+with open('downloaded.pdf', 'wb') as f:
+    f.write(response.content)""",
     },
     "request_format": {
         "method": "Operation name (required)",

tests/integration/mock_grist/server.py

@@ -35,6 +35,18 @@ MOCK_TABLES = {
             {"id": 2, "fields": {"Title": "Deploy", "Done": False}},
         ],
     },
+    "Orders": {
+        "columns": [
+            {"id": "OrderNum", "fields": {"type": "Int"}},
+            {"id": "Customer", "fields": {"type": "Ref:People"}},
+            {"id": "Amount", "fields": {"type": "Numeric"}},
+        ],
+        "records": [
+            {"id": 1, "fields": {"OrderNum": 1001, "Customer": 1, "Amount": 100.0}},
+            {"id": 2, "fields": {"OrderNum": 1002, "Customer": 2, "Amount": 200.0}},
+            {"id": 3, "fields": {"OrderNum": 1003, "Customer": 1, "Amount": 150.0}},
+        ],
+    },
 }
 
 # Track requests for test assertions
@@ -93,12 +105,40 @@ async def get_records(request):
     """GET /api/docs/{doc_id}/tables/{table_id}/records"""
     doc_id = request.path_params["doc_id"]
     table_id = request.path_params["table_id"]
-    log_request("GET", f"/api/docs/{doc_id}/tables/{table_id}/records")
+    filter_param = request.query_params.get("filter")
+    log_request("GET", f"/api/docs/{doc_id}/tables/{table_id}/records?filter={filter_param}")
 
     if table_id not in MOCK_TABLES:
         return JSONResponse({"error": "Table not found"}, status_code=404)
 
-    return JSONResponse({"records": MOCK_TABLES[table_id]["records"]})
+    records = MOCK_TABLES[table_id]["records"]
+
+    # Apply filtering if provided
+    if filter_param:
+        try:
+            filters = json.loads(filter_param)
+            # Validate filter format: all values must be arrays (Grist API requirement)
+            for key, values in filters.items():
+                if not isinstance(values, list):
+                    return JSONResponse(
+                        {"error": f"Filter values must be arrays, got {type(values).__name__} for '{key}'"},
+                        status_code=400
+                    )
+            # Apply filters: record matches if field value is in the filter list
+            filtered_records = []
+            for record in records:
+                match = True
+                for key, allowed_values in filters.items():
+                    if record["fields"].get(key) not in allowed_values:
+                        match = False
+                        break
+                if match:
+                    filtered_records.append(record)
+            records = filtered_records
+        except json.JSONDecodeError:
+            return JSONResponse({"error": "Invalid filter JSON"}, status_code=400)
+
+    return JSONResponse({"records": records})
 
 
 async def add_records(request):

tests/integration/test_tools_integration.py

@@ -90,6 +90,36 @@ async def test_all_tools(services_ready):
         log = get_mock_request_log()
         assert any("/records" in entry["path"] and entry["method"] == "GET" for entry in log)
 
+        # Test get_records with Ref column filter
+        # This tests that single values are normalized to arrays for the Grist API
+        clear_mock_request_log()
+        result = await client.call_tool(
+            "get_records",
+            {"document": "test-doc", "table": "Orders", "filter": {"Customer": 1}}
+        )
+        data = json.loads(result.content[0].text)
+        assert "records" in data
+        # Should return only orders for Customer 1 (orders 1 and 3)
+        assert len(data["records"]) == 2
+        for record in data["records"]:
+            assert record["Customer"] == 1
+        log = get_mock_request_log()
+        # Verify the filter was sent as array format
+        filter_requests = [e for e in log if "/records" in e["path"] and "filter=" in e["path"]]
+        assert len(filter_requests) >= 1
+        # The filter value should be [1] not 1
+        assert "[1]" in filter_requests[0]["path"]
+
+        # Test get_records with multiple filter values
+        clear_mock_request_log()
+        result = await client.call_tool(
+            "get_records",
+            {"document": "test-doc", "table": "Orders", "filter": {"Customer": [1, 2]}}
+        )
+        data = json.loads(result.content[0].text)
+        assert "records" in data
+        assert len(data["records"]) == 3  # All 3 orders (customers 1 and 2)
+
         # Test sql_query
         clear_mock_request_log()
         result = await client.call_tool(

tests/unit/test_filters.py

@@ -0,0 +1,89 @@
+"""Unit tests for filter normalization."""
+
+import pytest
+
+from grist_mcp.tools.filters import normalize_filter, normalize_filter_value
+
+
+class TestNormalizeFilterValue:
+    """Tests for normalize_filter_value function."""
+
+    def test_int_becomes_list(self):
+        assert normalize_filter_value(5) == [5]
+
+    def test_string_becomes_list(self):
+        assert normalize_filter_value("foo") == ["foo"]
+
+    def test_float_becomes_list(self):
+        assert normalize_filter_value(3.14) == [3.14]
+
+    def test_list_unchanged(self):
+        assert normalize_filter_value([1, 2, 3]) == [1, 2, 3]
+
+    def test_empty_list_unchanged(self):
+        assert normalize_filter_value([]) == []
+
+    def test_single_item_list_unchanged(self):
+        assert normalize_filter_value([42]) == [42]
+
+    def test_mixed_type_list_unchanged(self):
+        assert normalize_filter_value([1, "foo", 3.14]) == [1, "foo", 3.14]
+
+
+class TestNormalizeFilter:
+    """Tests for normalize_filter function."""
+
+    def test_none_returns_none(self):
+        assert normalize_filter(None) is None
+
+    def test_empty_dict_returns_empty_dict(self):
+        assert normalize_filter({}) == {}
+
+    def test_single_int_value_wrapped(self):
+        result = normalize_filter({"Transaction": 44})
+        assert result == {"Transaction": [44]}
+
+    def test_single_string_value_wrapped(self):
+        result = normalize_filter({"Status": "active"})
+        assert result == {"Status": ["active"]}
+
+    def test_list_value_unchanged(self):
+        result = normalize_filter({"Transaction": [44, 45, 46]})
+        assert result == {"Transaction": [44, 45, 46]}
+
+    def test_mixed_columns_all_normalized(self):
+        """Both ref and non-ref columns are normalized to arrays."""
+        result = normalize_filter({
+            "Transaction": 44,  # Ref column (int)
+            "Debit": 500,       # Non-ref column (int)
+            "Memo": "test",     # Non-ref column (str)
+        })
+        assert result == {
+            "Transaction": [44],
+            "Debit": [500],
+            "Memo": ["test"],
+        }
+
+    def test_multiple_values_list_unchanged(self):
+        """Filter with multiple values passes through."""
+        result = normalize_filter({
+            "Status": ["pending", "active"],
+            "Priority": [1, 2, 3],
+        })
+        assert result == {
+            "Status": ["pending", "active"],
+            "Priority": [1, 2, 3],
+        }
+
+    def test_mixed_single_and_list_values(self):
+        """Mix of single values and lists."""
+        result = normalize_filter({
+            "Transaction": 44,            # Single int
+            "Status": ["open", "closed"],  # List
+            "Amount": 100.50,             # Single float
+        })
+        assert result == {
+            "Transaction": [44],
+            "Status": ["open", "closed"],
+            "Amount": [100.50],
+        }

tests/unit/test_grist_client.py

@@ -236,3 +236,59 @@ async def test_upload_attachment_default_content_type(client, httpx_mock: HTTPXM
 
     assert result["attachment_id"] == 99
     assert result["size_bytes"] == 3
+
+
+@pytest.mark.asyncio
+async def test_download_attachment(client, httpx_mock: HTTPXMock):
+    httpx_mock.add_response(
+        url="https://grist.example.com/api/docs/abc123/attachments/42/download",
+        method="GET",
+        content=b"PDF content here",
+        headers={
+            "content-type": "application/pdf",
+            "content-disposition": 'attachment; filename="invoice.pdf"',
+        },
+    )
+
+    result = await client.download_attachment(42)
+
+    assert result["content"] == b"PDF content here"
+    assert result["content_type"] == "application/pdf"
+    assert result["filename"] == "invoice.pdf"
+
+
+@pytest.mark.asyncio
+async def test_download_attachment_no_filename(client, httpx_mock: HTTPXMock):
+    httpx_mock.add_response(
+        url="https://grist.example.com/api/docs/abc123/attachments/99/download",
+        method="GET",
+        content=b"binary data",
+        headers={
+            "content-type": "application/octet-stream",
+        },
+    )
+
+    result = await client.download_attachment(99)
+
+    assert result["content"] == b"binary data"
+    assert result["content_type"] == "application/octet-stream"
+    assert result["filename"] is None
+
+
+@pytest.mark.asyncio
+async def test_download_attachment_unquoted_filename(client, httpx_mock: HTTPXMock):
+    httpx_mock.add_response(
+        url="https://grist.example.com/api/docs/abc123/attachments/55/download",
+        method="GET",
+        content=b"image data",
+        headers={
+            "content-type": "image/png",
+            "content-disposition": "attachment; filename=photo.png",
+        },
+    )
+
+    result = await client.download_attachment(55)
+
+    assert result["content"] == b"image data"
+    assert result["content_type"] == "image/png"
+    assert result["filename"] == "photo.png"

tests/unit/test_tools_read.py

@@ -75,6 +75,45 @@ async def test_get_records(agent, auth, mock_client):
     assert result == {"records": [{"id": 1, "Name": "Alice"}]}
 
 
+@pytest.mark.asyncio
+async def test_get_records_normalizes_filter(agent, auth, mock_client):
+    """Test that filter values are normalized to array format for Grist API."""
+    mock_client.get_records.return_value = [{"id": 1, "Customer": 5}]
+
+    await get_records(
+        agent, auth, "budget", "Orders",
+        filter={"Customer": 5, "Status": "active"},
+        client=mock_client,
+    )
+
+    # Verify filter was normalized: single values wrapped in lists
+    mock_client.get_records.assert_called_once_with(
+        "Orders",
+        filter={"Customer": [5], "Status": ["active"]},
+        sort=None,
+        limit=None,
+    )
+
+
+@pytest.mark.asyncio
+async def test_get_records_preserves_list_filter(agent, auth, mock_client):
+    """Test that filter values already in list format are preserved."""
+    mock_client.get_records.return_value = []
+
+    await get_records(
+        agent, auth, "budget", "Orders",
+        filter={"Customer": [5, 6, 7]},
+        client=mock_client,
+    )
+
+    mock_client.get_records.assert_called_once_with(
+        "Orders",
+        filter={"Customer": [5, 6, 7]},
+        sort=None,
+        limit=None,
+    )
+
+
 @pytest.mark.asyncio
 async def test_sql_query(agent, auth, mock_client):
     result = await sql_query(agent, auth, "budget", "SELECT * FROM Table1", client=mock_client)

tests/unit/test_tools_session.py

@@ -41,12 +41,14 @@ async def test_get_proxy_documentation_returns_complete_spec():
     assert "description" in result
     assert "endpoints" in result
     assert "proxy" in result["endpoints"]
-    assert "attachments" in result["endpoints"]
+    assert "attachments_upload" in result["endpoints"]
+    assert "attachments_download" in result["endpoints"]
     assert "authentication" in result
     assert "methods" in result
     assert "add_records" in result["methods"]
     assert "get_records" in result["methods"]
     assert "attachment_upload" in result
+    assert "attachment_download" in result
     assert "example_script" in result
 
 

uv.lock

@@ -153,7 +153,7 @@ wheels = [
 
 [[package]]
 name = "grist-mcp"
-version = "1.2.0"
+version = "1.3.0"
 source = { editable = "." }
 dependencies = [
     { name = "httpx" },