Hardened MCP Google Workspace Verified Secure Scriptable

The Secure, Unlimited
Apps Script Bridge
for AI Agents.

Deploy in 60 seconds. Hardened by a 38-pattern safety engine. Your data never leaves Google.

Compatible with Claude Desktop Cursor Windsurf Cline
PathFinder · Spec Sheetv1.0
Deploy time~60 sec
Safety patterns38
Permission tiers4
MCP tools9
Data residencyGoogle
Auth methodHMAC-SHA256
TransportHTTPS / MCP
Undo buffer5 ops
Exec log100 rolling
Price$5 / month

Other MCPs give your AI a spoon.
We give it the entire API.

01 / ARCHITECTURE
How PathFinder Works

A hardened bridge between
your AI and your spreadsheet.

A Vercel Edge proxy sits between your AI and your spreadsheet — authenticating every request, enforcing permission tiers, and executing code inside your own Google account.

AI CLIENT Claude · Cursor · Windsurf MCP / HTTPS PROXY Vercel Edge · Supabase HMAC AUTH APPS SCRIPT 38-pattern · Tier enforce VALIDATED SPREADSHEET Data never leaves here ANY MCP HTTP CLIENT AUTH + RATE + LOG YOUR GOOGLE ACCOUNT ZERO DATA EGRESS
01

Purchase

Subscribe via LemonSqueezy. Receive your Marketplace install link instantly.

02

Install Add-on

Install PathFinder from Google Workspace Marketplace. One click.

03

Deploy Script

Create an Apps Script project with the 3-line wrapper + library ref. Deploy as web app.

04

Enable MCP

Open the PathFinder sidebar in your spreadsheet. Choose a tier. Activate your endpoint.

05

Connect AI

Paste the URL and token into your AI tool's MCP config. Done.

02 / THE PROBLEM
Total AI Control. Zero Data Leakage.

Stop Copy-Pasting.
Let Your AI Own the Spreadsheet.

Other Sheets MCPs are wrappers with a hardcoded list of moves. PathFinder is an execution engine — your AI writes real Apps Script and runs it.

Other Sheets MCPs
  • 5–10 hardcoded tools, no exceptions
  • Can't handle custom or complex workflows
  • No formatting, formulas, or automations
  • No permission model or security enforcement
  • Breaks outside its predefined scope
PathFinder
  • Unlimited operations via real Apps Script execution
  • Full read, write, format, formula, dependency support
  • Automations, email triggers, undo buffer, dry run
  • 4 permission tiers enforced server-side, per token
  • Code runs in your Google account — data never leaves
03 / CAPABILITIES
What Your AI Can Actually Do

Describe it. PathFinder executes it.

No predefined tool limits. Your AI writes the Apps Script. PathFinder validates and runs it. If Sheets can do it, your AI can do it.

Prompt to your AIWhat PathFinder executes
"Summarize this spreadsheet"Reads structure, formulas, and cross-sheet relationships. Returns a plain-English overview.
"Find broken formula references"Scans every formula for #REF! errors, dead ranges, and circular dependencies.
"Map how these sheets depend on each other"Builds a full dependency graph including cross-sheet and IMPORTRANGE references.
"Highlight all rows where sales > 1000"Writes and executes Apps Script to apply conditional formatting across the range.
"Add a column calculating 10% commission"Inserts the correct formula down the entire range, handling edge cases automatically.
"Email me a daily summary of new orders"Installs a time-based automation with Gmail integration. Runs on schedule, no prompting.
"Undo what you just did"Reverts the last write operation from the undo buffer. Stores the last 5 operations.
"What breaks if I delete column B?"Traverses the dependency tree and returns an impact report before anything changes.
04 / MCP TOOLS
9 Purpose-Built Tools

A complete reference API
for your spreadsheet.

Structured MCP tools your AI can call directly — from dependency analysis to full script execution and automation management.

ToolTypeDescription
scan_dependenciesreadFull dependency map including cross-sheet and IMPORTRANGE references.
get_sheet_structurereadSheet names, formula layout, and cross-sheet relationships.
get_formula_analysisreadDeep formula breakdown per sheet — types, ranges, and complexity.
get_broken_refsreadFind broken, dead, or circular formula references across the workbook.
get_sheet_summaryreadPlain-English overview of spreadsheet purpose, structure, and key data.
execute_codewriteValidate and run Apps Script via the full execution engine.
install_automationwriteStore code and create a persistent time-based trigger.
delete_automationwriteRemove an installed automation and its associated trigger.
list_automationsreadView all installed automations with current status and schedule.
05 / ACCESS CONTROL
Four Permission Tiers

Your token defines the boundary.
The server enforces it.

Tiers are encoded in your MCP token and enforced server-side on every request. Generate different tokens per project or collaborator.

TierDescriptionReadWriteEmailAutomate
Read OnlyScan, analyze, read formulas. Nothing modified.
Read + WriteEdit cells, formulas, formatting, insert/delete rows.
R+W + EmailEverything above, plus send emails via Gmail.
Full AccessEverything above, plus URL fetching and time-based automations.
Always Blocked
delete sheetsremove editorsread inboxeval()new Function()access internal config
06 / SECURITY
3-Layer Safety Model

Security at every layer,
not just at the edge.

From AI guidance to server enforcement to runtime validation — PathFinder applies safety checks at every point in the execution chain.

Layer 01

AI Self-Regulation

Tool descriptions guide the AI toward safe operations before any code is written. Safe by design, not just by policy.

Layer 02

Server-Side Enforcement

38-pattern blocklist. Pre-processing strips Unicode/URL encoding, comment obfuscation, and whitespace normalization. Bracket notation bypass detection.

Layer 03

Tier + Rate Enforcement

Permission tiers enforced per token. 60 exec/hr, 10 writes/min, 2 emails/min. Your token cannot exceed its configured tier — ever.

HMAC-SHA256 auth on every request
SHA-256 code integrity for automations
Proxy tokens hashed before storage
Undo buffer — last 5 write operations
Rolling execution log — 100 entries
Dry run mode — analyze before executing
Subscription verified on every request
Plaintext tokens never stored
07 / RATE LIMITS
Operational Limits

Generous for real workflows.
Hard caps for safety.

Rate limits prevent runaway executions and protect your Google account without getting in the way of normal use.

OperationRateDaily LimitNotes
execute_code60 / hr500 / dayEnforced by proxy
write operations10 / minAll cell and formula writes
email sends2 / min100 / dayR+W+Email tier and above
automation installs1 / sessionFull Access tier only
08 / PRICING
One Plan. Everything Included.

All tools. All tiers. Cancel anytime.

No seat limits. No feature gating. Unlimited operations within rate limits.

PathFinder Pro ⊕ 7-day free trial
Monthly price$5.00
Free trial7 days · no card required
BillingMonthly · cancel anytime
ScopePer Google account · no seat limits
Includes: 9 MCP tools · all 4 permission tiers · unlimited operations
3-layer security · 38-pattern blocklist · HMAC-SHA256 auth
undo buffer · execution log · email automations · dry run mode

No credit card required to start.

09 / FAQ
Common Questions

Before you get started.

Everything you need to know about PathFinder.

Most Sheets MCPs expose 5–10 hardcoded tools — get_cell, set_cell, and not much else. PathFinder is an execution engine: your AI writes real Google Apps Script and PathFinder validates and runs it. If Sheets can do it, your AI can do it. No predefined ceiling on operations.

No. The Vercel proxy handles authentication and subscription checks, then forwards the request to your Apps Script deployment — which runs inside your own Google account. Your spreadsheet data never leaves Google's infrastructure. The proxy sees code to execute, not your data.

Your MCP token encodes a permission tier enforced server-side on every request. Even if you ask your AI to exceed its scope, the request is rejected before any code runs. You can generate tokens with different tiers for different projects or collaborators from the PathFinder sidebar.

PathFinder maintains an undo buffer of the last 5 write operations. Tell your AI to undo and it restores the previous state precisely. Every operation is captured in a rolling execution log (100 entries). Dry run mode lets you preview what code would execute before it runs.

Most users are running in under 10 minutes: purchase → install the Marketplace add-on → create the 3-line Apps Script wrapper → deploy as web app → enable MCP in your spreadsheet → paste credentials into your AI tool's MCP config. Full setup guide included with your purchase.

Claude Desktop (streamable-http transport), Cursor, Windsurf, and Cline are supported out of the box. Any MCP-compatible client that supports HTTP transport will work — PathFinder uses the standard MCP protocol.