Upsert rows - update existing rows by key, append new ones. Automatically handles column mapping and partial updates. Use for: CRM syncs (match Lead ID), transaction imports (match Transaction ID), inventory updates (match SKU), calendar syncs (match Event ID). Features: - Auto-adds missing colum...
Part of the Google Sheets server.
Free to start. No card required.
AI agents use GOOGLESHEETS_UPSERT_ROWS to create or modify resources in Google Sheets. Write operations carry medium risk because an autonomous agent could trigger bulk unintended modifications. Rate limits prevent a single agent session from making hundreds of changes in rapid succession. Argument validation ensures the agent passes expected values.
Without a policy, an AI agent could call GOOGLESHEETS_UPSERT_ROWS repeatedly, creating or modifying resources faster than any human could review. PolicyLayer's rate limiting ensures write operations happen at a controlled pace, and argument validation catches malformed or unexpected inputs before they reach Google Sheets.
Write tools can modify data. A rate limit prevents runaway bulk operations from AI agents.
{
"version": "1",
"default": "deny",
"tools": {
"GOOGLESHEETS_UPSERT_ROWS": {
"limits": [
{
"counter": "googlesheets_upsert_rows_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}See the full Google Sheets policy for all 38 tools.
These attack patterns abuse exactly the kind of access GOOGLESHEETS_UPSERT_ROWS gives an agent. Each links to the full case and the policy that stops it:
Other write tools across the catalogue. The same approach applies to each: rate-limit and validate the arguments.
Upsert rows - update existing rows by key, append new ones. Automatically handles column mapping and partial updates. Use for: CRM syncs (match Lead ID), transaction imports (match Transaction ID), inventory updates (match SKU), calendar syncs (match Event ID). Features: - Auto-adds missing columns to sheet - Partial column updates (only update Phone + Status, preserve other columns) - Column order doesn't matter (auto-maps by header name) - Prevents duplicates by matching key column Example inputs: - Contact update: keyColumn='Email', headers=['Email','Phone','Status'], data=[['john@ex.com','555-0101','Active']] - Inventory sync: keyColumn='SKU', headers=['SKU','Stock','Price'], data=[['WIDGET-001',50,9.99],['GADGET-002',30,19.99]] - CRM lead update: keyColumn='Lead ID', headers=['Lead ID','Score','Status'], data=[['L-12345',85,'Hot']] - Partial update: keyColumn='Email', headers=['Email','Phone'] (only updates Phone, preserves Name/Address/etc). It is categorised as a Write tool in the Google Sheets MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Google Sheets MCP server in PolicyLayer and add a rule for GOOGLESHEETS_UPSERT_ROWS: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Google Sheets. Nothing to install.
GOOGLESHEETS_UPSERT_ROWS is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the GOOGLESHEETS_UPSERT_ROWS rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for GOOGLESHEETS_UPSERT_ROWS. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
GOOGLESHEETS_UPSERT_ROWS is provided by the Google Sheets MCP server (google-sheets-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 38 Google Sheets tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
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