Quotas & Limits¶

All quotas are enforced by Google and apply per Google account. This page documents the constraints you'll encounter when using the Apps Script MCP servers.

Apps Script Quotas¶

These limits apply to every Apps Script web app deployment:

Limit	Value	Notes
Execution time	6 minutes per request	After 6 min, the script is terminated. Batch operations share this time budget across all operations.
URL Fetch calls	20,000 per day	The proxy itself doesn't make outbound URL Fetch calls during normal operation, but Apps Script internal API calls may count against this if they use UrlFetchApp under the hood.
Total trigger runtime	90 minutes per day (consumer) / 6 hours (Workspace)	Not relevant for web app deployments (no triggers used).
Simultaneous executions	30	Max concurrent web app requests.
Script property storage	500 KB per script	Token and bootstrap flag consume < 200 bytes. Not a practical concern.
CacheService storage	100 KB per script	Rate limit counters use ~10 bytes per key. Not a practical concern.

Source: Google Apps Script Quotas

Per-Proxy Rate Limiting¶

Each proxy applies its own rate limit, independent of Google API quotas:

Limit	Value
Weighted units per minute	100 per proxy
Authenticated request cost	Weighted by action risk and batch operations
Failed authentication attempts	20 per minute per supplied token/missing-token bucket
Reset window	60 seconds
Error when exceeded	`RATE_LIMITED: "Too many requests. Try again in 60 seconds."`

This rate limit is enforced by CacheService.getScriptCache() under a script lock in the Apps Script proxy layer and is independent of the per-API quotas below. If the lock cannot be acquired, the request fails closed as rate-limited.

Enforced Proxy Limits¶

The proxy rejects requests before or immediately after bounded API calls when they exceed these limits. Limit failures use LIMIT_EXCEEDED with the requested and maximum values in the message.

Limit	Value
Request body payload	1,000,000 characters

Drive Proxy¶

Limit	Value
Page size (`drive_list_files`, `drive_search_files`, comment/reply/revision/shared-drive/change lists)	100
Maximum page offset	5,000
Folder entries returned by `drive_list_folders`	200
Text returned by `drive_read_file`	500,000 characters
Export bytes (`drive_read_file`, `drive_export_as`)	5,000,000 bytes
Text write payload (`drive_create_file`, `drive_update_content`)	1,000,000 characters
Folder path depth	50
Total response payload	1,000,000 JSON characters

Gmail Proxy¶

Limit	Value
Page size (`gmail_search_messages`, `gmail_list_threads`, `gmail_list_drafts`)	100
Maximum page offset	5,000
Threads scanned per message search page	200
Messages returned from a single thread	100
Drafts scanned	500
Message/draft body field	100,000 characters
Attachment bytes	5,000,000 bytes
`gmail_batch_modify` message IDs	500
Gmail filters per account	1,000 (Gmail API limit)
Total response payload	1,000,000 JSON characters

Calendar Proxy¶

Limit	Value
Page size (`calendar_list_events`, `calendar_search_events`)	100
Maximum page offset	5,000
Event/free-busy/instance date window	31 days
Total response payload	1,000,000 JSON characters

Sheets Proxy¶

Limit	Value
Cells read per operation	10,000
Cells written or mutated per range operation	10,000
Ranges in `sheets_batch_get`	10
Rows inserted/deleted per call	5,000
Total response payload	1,000,000 JSON characters

Docs Proxy¶

Limit	Value
Paragraphs returned by `docs_get_document`	500
Characters returned by `docs_get_document`	500,000
Full document JSON payload	1,000,000 JSON characters
Total response payload	1,000,000 JSON characters

Slides Proxy¶

Limit	Value
Page elements returned by `slides_get_slide_elements`	200
Text returned from slide elements or notes	200,000 characters
Total response payload	1,000,000 JSON characters

Tasks Proxy¶

Limit	Value
Task lists returned by `tasks_list_tasklists`	100
Tasks returned by `tasks_list_tasks`	100
Task or task list title	1,024 characters
Task notes	10,000 characters
Total response payload	1,000,000 JSON characters

Forms Proxy¶

Limit	Value
Form items returned by `forms_list_items`	200
Responses returned by `forms_list_responses`	100
Answers returned per response	100
Form or item title	1,024 characters
Form descriptions, messages, and item help text	10,000 characters
Choices per choice item	200
Characters per choice label	500
Total response payload	1,000,000 JSON characters

Per-Service API Quotas¶

These are Google API quotas enforced by the underlying Workspace APIs. The proxy uses Apps Script built-in services (DriveApp, GmailApp, CalendarApp, etc.) which have their own undocumented internal quotas. The numbers below represent observed behavior:

Drive¶

Limit	Value
File read/write operations	No documented hard limit; throttled at high volumes
File size for content read (`drive_read_file`)	5,000,000 source bytes and 500,000 returned characters (enforced by the proxy, not Google)
Search results per query	100 per proxy call
Sharing changes per file	No documented limit
Trash/delete operations	No documented limit

Gmail¶

Limit	Value
Messages read per day	20,000 (GmailApp quota)
Emails sent per day	100 (free Gmail) / 2,000 (Google Workspace)
Email recipients per message	500 (free) / 1,500 (Workspace)
Draft creation per day	No documented limit
Label operations per day	No documented limit
Search results per query	100 per proxy call; bounded thread scan

Calendar¶

Limit	Value
Events created per day	10,000 (Calendar API quota)
Events read per day	1,000,000 (Calendar API quota)
Free/busy queries per day	No documented limit
Calendars accessible	All calendars the user has access to

Sheets¶

Limit	Value
Cells read per proxy call	10,000
Cells written per proxy call	10,000
Spreadsheets accessible	200 spreadsheets open simultaneously
Sheet tabs per spreadsheet	200
Rows per sheet	100,000
Cells per spreadsheet	10,000,000
Charts per spreadsheet	100

Slides¶

Limit	Value
Slides per presentation	200
Elements returned per slide by proxy	200
Presentations accessible	No documented limit
Image size for insertion	No documented limit (URL must be publicly accessible)

Docs¶

Limit	Value
Document characters returned by proxy	500,000
Paragraphs returned by proxy	500
Tables per document	No documented hard limit
Images per document	No documented limit

Tasks¶

Limit	Value
Task lists per account	No documented hard limit
Tasks returned per proxy call	100
Task title length	1,024 characters
Task notes returned/written by proxy	10,000 characters

Forms¶

Limit	Value
Form items returned per proxy call	200
Form responses returned per proxy call	100
Supported item types	Text, paragraph, multiple choice, checkbox, list, scale, date, time, section header, page break
Response destination	Google Sheets spreadsheet via `FormApp.setDestination`

Content Limits¶

File Read Truncation¶

The drive_read_file operation truncates file content at 500,000 characters after enforcing a 5,000,000 byte source/export size cap:

{
  "content": "...first 500,000 characters of file...",
  "truncated": true,
  "size": 1200000
}

When content is truncated, the truncated field is true and the size field shows the full file size. The proxy does this to stay within Apps Script execution limits and avoid timeout on large files.

Batch Operation Limits¶

Limit	Value
Operations per batch	20 max
Error when exceeded	`LIMIT_EXCEEDED`
Minimum batch size	1 operation
Error when empty	`BAD_REQUEST: "operations must be a non-empty array"`

Batch operations share the 6-minute execution time budget and are charged by operation weight for rate limiting. A batch of 20 read operations is fast; a batch of 20 file creation operations may take longer.

What Happens When Quotas Are Hit¶

Rate Limit (100 weighted units/minute proxy limit)¶

The proxy returns an error before any API call:

{
  "success": false,
  "error": {
    "code": "RATE_LIMITED",
    "message": "Too many requests. Try again in 60 seconds."
  }
}

The agent should wait and retry. The rate limit counter resets 60 seconds after the first request in the window.

Google API Quota Exceeded¶

The proxy may return:

{
  "success": false,
  "error": {
    "code": "INTERNAL_ERROR",
    "message": "An internal error occurred. Check developer console logs for details."
  }
}

This is a generic error that can mean quota exhaustion, API throttling, or an unexpected exception. For persistent quota issues:

Check Apps Script logs in the script editor (Executions tab).
For Gmail daily send limits, wait until the next UTC day.
For Calendar or Drive quotas, spread operations across time.

Execution Timeout (6 minutes)¶

If a request exceeds 6 minutes, Apps Script terminates it. No error is returned to the MCP server; the HTTP connection is dropped. The MCP server will report a network error or timeout. Long-running batch operations (e.g., iterating over thousands of Drive files) are the most likely trigger. Move such workloads to paginated individual calls.

Hard Proxy Limits¶

When a proxy limit is exceeded, the proxy returns:

{
  "success": false,
  "error": {
    "code": "LIMIT_EXCEEDED",
    "message": "rangeRead cells limit exceeded: requested 20000, max 10000"
  }
}

For truncated text fields, the response includes a *Truncated boolean where practical. For hard byte, cell, date-window, and batch limits, reduce the requested page size, date range, range size, or batch size and retry.