spanner-list-graphs Tool
A “spanner-list-graphs” tool retrieves schema information about graphs in a Google Cloud Spanner database.
4 minute read
About
A spanner-list-graphs tool retrieves comprehensive schema information about
graphs in a Cloud Spanner database. It returns detailed metadata including
node tables, edge tables, labels and property declarations.
Features
- Comprehensive Schema Information: Returns node tables, edge tables, labels and property declarations
- Flexible Filtering: Can list all graphs or filter by specific graph names
- Output Format Options: Choose between simple (graph names only) or detailed (full schema information) output
Use Cases
- Database Documentation: Generate comprehensive documentation of your database schema
- Schema Validation: Verify that expected graphs, node and edge exist
- Migration Planning: Understand the current schema before making changes
- Development Tools: Build tools that need to understand database structure
- Audit and Compliance: Track schema changes and ensure compliance with data governance policies
This tool is read-only and executes pre-defined SQL queries against the
INFORMATION_SCHEMA tables to gather metadata.
Warning
The tool only works for the GoogleSQL source dialect, as Spanner Graph isn’t available in the PostgreSQL dialect.
Compatible Sources
This tool can be used with the following database sources:
| Source Name |
|---|
| Spanner Source |
Parameters
The tool accepts two optional parameters:
| parameter | type | default | description |
|---|---|---|---|
| graph_names | string | "" | Comma-separated list of graph names to filter. If empty, lists all graphs in user-accessible schemas |
| output_format | string | “detailed” | Output format: “simple” returns only graph names, “detailed” returns full schema information |
Example
Basic Usage - List All Graphs
kind: sources
name: my-spanner-db
type: spanner
project: ${SPANNER_PROJECT}
instance: ${SPANNER_INSTANCE}
database: ${SPANNER_DATABASE}
dialect: googlesql # wont work for postgresql
---
kind: tools
name: list_all_graphs
type: spanner-list-graphs
source: my-spanner-db
description: Lists all graphs with their complete schema information
List Specific Graphs
kind: tools
name: list_specific_graphs
type: spanner-list-graphs
source: my-spanner-db
description: |
Lists schema information for specific graphs.
Example usage:
{
"graph_names": "FinGraph,SocialGraph",
"output_format": "detailed"
}
Output Format
Simple Format
When output_format is set to “simple”, the tool returns a minimal JSON structure:
[
{
"object_details": {
"name": "FinGraph"
},
"object_name": "FinGraph",
"schema_name": ""
},
{
"object_details": {
"name": "SocialGraph"
},
"object_name": "SocialGraph",
"schema_name": ""
}
]
Detailed Format
When output_format is set to “detailed” (default), the tool returns
comprehensive schema information:
[
{
"object_details": {
"catalog": "",
"edge_tables": [
{
"baseCatalogName": "",
"baseSchemaName": "",
"baseTableName": "Knows",
"destinationNodeTable": {
"edgeTableColumns": [
"DstId"
],
"nodeTableColumns": [
"Id"
],
"nodeTableName": "Person"
},
"keyColumns": [
"SrcId",
"DstId"
],
"kind": "EDGE",
"labelNames": [
"Knows"
],
"name": "Knows",
"propertyDefinitions": [
{
"propertyDeclarationName": "DstId",
"valueExpressionSql": "DstId"
},
{
"propertyDeclarationName": "SrcId",
"valueExpressionSql": "SrcId"
}
],
"sourceNodeTable": {
"edgeTableColumns": [
"SrcId"
],
"nodeTableColumns": [
"Id"
],
"nodeTableName": "Person"
}
}
],
"labels": [
{
"name": "Knows",
"propertyDeclarationNames": [
"DstId",
"SrcId"
]
},
{
"name": "Person",
"propertyDeclarationNames": [
"Id",
"Name"
]
}
],
"node_tables": [
{
"baseCatalogName": "",
"baseSchemaName": "",
"baseTableName": "Person",
"keyColumns": [
"Id"
],
"kind": "NODE",
"labelNames": [
"Person"
],
"name": "Person",
"propertyDefinitions": [
{
"propertyDeclarationName": "Id",
"valueExpressionSql": "Id"
},
{
"propertyDeclarationName": "Name",
"valueExpressionSql": "Name"
}
]
}
],
"object_name": "SocialGraph",
"property_declarations": [
{
"name": "DstId",
"type": "INT64"
},
{
"name": "Id",
"type": "INT64"
},
{
"name": "Name",
"type": "STRING"
},
{
"name": "SrcId",
"type": "INT64"
}
],
"schema_name": ""
},
"object_name": "SocialGraph",
"schema_name": ""
}
]
Reference
| field | type | required | description |
|---|---|---|---|
| type | string | true | Must be “spanner-list-graphs” |
| source | string | true | Name of the Spanner source to query (dialect must be GoogleSQL) |
| description | string | false | Description of the tool that is passed to the LLM |
| authRequired | string[] | false | List of auth services required to invoke this tool |
Advanced Usage
Example with Agent Integration
kind: sources
name: spanner-db
type: spanner
project: my-project
instance: my-instance
database: my-database
dialect: googlesql
---
kind: tools
name: schema_inspector
type: spanner-list-graphs
source: spanner-db
description: |
Use this tool to inspect database schema information.
You can:
- List all graphs by leaving graph_names empty
- Get specific graph schemas by providing comma-separated graph names
- Choose between simple (names only) or detailed (full schema) output
Examples:
1. List all graphs with details: {"output_format": "detailed"}
2. Get specific graphs: {"graph_names": "FinGraph,SocialGraph", "output_format": "detailed"}
3. Just get graph names: {"output_format": "simple"}
Troubleshooting
- This tool is read-only and does not modify any data
- The tool only works for the GoogleSQL source dialect
- Large databases with many graphs may take longer to query
Feedback
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