Google Contacts: Update many contacts — MCP tool

Google Contacts MCP tool: Updates up to 200 contacts in a single atomic request with a shared update mask.

Technical name: batch_update_contacts

What task it solves

I want to change many contacts in one go.

Updates up to 200 contacts in ONE request — each entry names a contact and the field groups to replace on it.

When to use it

Use it for bulk edits (e.g. re-labeling company names after a merger). For a single contact use update_contact.

What to provide

• updates — required. 1..200 entries: resource_name, optional etag (fetched automatically in one batch read when omitted), and the fields to replace.
• read_mask — optional. Fields to return for the updated people.

What it returns

updateResult keyed by resource name, each with the updated person.

What changes in Google Contacts

Provided field groups are REPLACED on the listed contacts. The wire update mask is shared by the whole batch (the union of every entry's groups): a group one entry provides and another omits gets CLEARED on the omitting one — give every entry the same groups or split the batch.

Example request

Set the organization "NewCo" on all 40 of these contacts.

Errors and limitations

Atomic: one stale etag or invalid entry fails the whole request — re-read and retry. Send mutate batches sequentially, never in parallel; never blindly re-send after an ambiguous failure. Access also depends on token permissions, quotas, and upstream API limits.

Related MCP tools

• Update a contact — update_contact
• Get many contacts at once — batch_get_contacts
• Create many contacts — batch_create_contacts

Technical details

• Impact: destructive operation
• Group: Batch operations
• Description source: batch_update_contacts registration in src/tools/batch.ts
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