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AgentMail Changelog

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May 28, 2026
May 28, 2026
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March 18, 2026

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Summary

Inboxes now support custom metadata: your own key-value data attached to any inbox. Link an inbox to records in your own system, such as a tenant ID, user ID, or feature flags, and read it back on every inbox response. Build agents that carry your application’s context wherever an inbox goes.

What’s new?

New features:

  • Inbox metadata: Attach custom key-value pairs to an inbox. Values may be a string, number, or boolean, with up to 256 keys per inbox.

Changes:

  • The Inbox object now includes an optional metadata field, returned on get, list, and create responses.
  • POST /v0/inboxes accepts a metadata field to set metadata at creation time.
  • PATCH /v0/inboxes/:inbox_id accepts a metadata field. Updates merge into existing metadata: keys you include are added or overwritten, and keys you omit are preserved. Send a key with a null value to remove it, or set metadata to null to clear everything. Each update must include at least one of display_name or metadata.

Use cases

Build agents that:

  • Tag each inbox with a tenant or customer ID so you can map inboxes back to your own data model
  • Store per-inbox feature flags or routing hints that your agent reads at runtime
  • Track lifecycle state, such as an onboarding step or campaign name, directly on the inbox
  • Filter and organize a large fleet of inboxes by the attributes that matter to your application
1from agentmail import AgentMail
2
3client = AgentMail(api_key="your-api-key")
4
5# attach metadata when creating an inbox
6inbox = client.inboxes.create(
7 username="support-agent",
8 metadata={"tenant_id": "acme", "tier": "pro", "active": True},
9)
10
11# merge in a change; omitted keys are preserved
12client.inboxes.update(
13 inbox_id=inbox.inbox_id,
14 metadata={"tier": "enterprise"},
15)

Learn more about attaching and updating inbox data in the Inboxes metadata guide.