diff --git a/src/grist_mcp/tools/session.py b/src/grist_mcp/tools/session.py
new file mode 100644
index 0000000..f1b957e
--- /dev/null
+++ b/src/grist_mcp/tools/session.py
@@ -0,0 +1,106 @@
+"""Session token tools for HTTP proxy access."""
+
+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.",
+    "endpoint": "POST /api/v1/proxy",
+    "authentication": "Bearer token in Authorization header",
+    "request_format": {
+        "method": "Operation name (required)",
+        "table": "Table name (required for most operations)",
+    },
+    "methods": {
+        "get_records": {
+            "description": "Fetch records from a table",
+            "fields": {
+                "table": "string",
+                "filter": "object (optional)",
+                "sort": "string (optional)",
+                "limit": "integer (optional)",
+            },
+        },
+        "sql_query": {
+            "description": "Run a read-only SQL query",
+            "fields": {"query": "string"},
+        },
+        "list_tables": {
+            "description": "List all tables in the document",
+            "fields": {},
+        },
+        "describe_table": {
+            "description": "Get column information for a table",
+            "fields": {"table": "string"},
+        },
+        "add_records": {
+            "description": "Add records to a table",
+            "fields": {"table": "string", "records": "array of objects"},
+        },
+        "update_records": {
+            "description": "Update existing records",
+            "fields": {"table": "string", "records": "array of {id, fields}"},
+        },
+        "delete_records": {
+            "description": "Delete records by ID",
+            "fields": {"table": "string", "record_ids": "array of integers"},
+        },
+        "create_table": {
+            "description": "Create a new table",
+            "fields": {"table_id": "string", "columns": "array of {id, type}"},
+        },
+        "add_column": {
+            "description": "Add a column to a table",
+            "fields": {
+                "table": "string",
+                "column_id": "string",
+                "column_type": "string",
+                "formula": "string (optional)",
+            },
+        },
+        "modify_column": {
+            "description": "Modify a column's type or formula",
+            "fields": {
+                "table": "string",
+                "column_id": "string",
+                "type": "string (optional)",
+                "formula": "string (optional)",
+            },
+        },
+        "delete_column": {
+            "description": "Delete a column",
+            "fields": {"table": "string", "column_id": "string"},
+        },
+    },
+    "response_format": {
+        "success": {"success": True, "data": "..."},
+        "error": {"success": False, "error": "message", "code": "ERROR_CODE"},
+    },
+    "error_codes": [
+        "UNAUTHORIZED",
+        "INVALID_TOKEN",
+        "TOKEN_EXPIRED",
+        "INVALID_REQUEST",
+        "GRIST_ERROR",
+    ],
+    "example_script": """#!/usr/bin/env python3
+import requests
+import sys
+
+token = sys.argv[1]
+host = sys.argv[2]
+
+response = requests.post(
+    f'{host}/api/v1/proxy',
+    headers={'Authorization': f'Bearer {token}'},
+    json={
+        'method': 'add_records',
+        'table': 'Orders',
+        'records': [{'item': 'Widget', 'qty': 100}]
+    }
+)
+print(response.json())
+""",
+}
+
+
+async def get_proxy_documentation() -> dict:
+    """Return complete documentation for the HTTP proxy API."""
+    return PROXY_DOCUMENTATION
diff --git a/tests/unit/test_tools_session.py b/tests/unit/test_tools_session.py
new file mode 100644
index 0000000..d1d3078
--- /dev/null
+++ b/tests/unit/test_tools_session.py
@@ -0,0 +1,16 @@
+import pytest
+from grist_mcp.tools.session import get_proxy_documentation
+
+
+@pytest.mark.asyncio
+async def test_get_proxy_documentation_returns_complete_spec():
+    result = await get_proxy_documentation()
+
+    assert "description" in result
+    assert "endpoint" in result
+    assert result["endpoint"] == "POST /api/v1/proxy"
+    assert "authentication" in result
+    assert "methods" in result
+    assert "add_records" in result["methods"]
+    assert "get_records" in result["methods"]
+    assert "example_script" in result