Stannp for AI agents

Stannp is a direct mail API that sends postcards and letters on a business's behalf, handling templates, recipient lists, and delivery tracking. Connect it once through Arc0, and your agent, or Claude, ChatGPT and Cursor, can use it through one MCP endpoint, limited to what each user approved.

Connect Stannp See the 32 actions ↓

MarketingAPI keyMCP + RESTstannp.com

AUDIT LOG · STANNPPOLICY: acme-support

09:41:07 · claude · u_8f2read

stannp.list_groups

List Mailing Groups✓ allowed · 212ms

09:41:08 · claude · u_8f2read

stannp.get_contact

Get Contact✓ allowed · 164ms

09:41:09 · claude · u_8f2write

stannp.create_group

Create recipient group✓ approved · approved by user

09:41:12 · claude · u_8f2destructive

stannp.delete_group

Delete recipient group✕ blocked · policy: deny

EVERY STANNP CALL, ON THE RECORD

01 · USE CASES

What agents do in Stannp.

Check account balance before a mailing

Check the account balance to confirm there's enough credit before a postcard batch goes out.

Send a postcard to a recipient list

Create a postcard campaign against an imported recipient list, using an approved template and design.

Confirm before canceling a postcard

Look up a postcard's status before canceling it, since cancellation only works before it enters production.

02 · ACTIONS

32 Stannp actions, graded by risk.

Every Stannp action is tagged read, write or destructive, so one policy covers the whole app and new actions inherit the right default.

read

Look things up. Allowed by default.

stannp.get_contact
Get Contact
stannp.list_groups
List Mailing Groups
stannp.get_campaign
Get Campaign
stannp.list_folders
List Folders
stannp.list_contacts
List Contacts
stannp.list_campaigns
List Campaigns
stannp.list_templates
List Templates
stannp.list_mailpieces
List Mailpieces
stannp.get_current_user
Get Current User
stannp.get_campaign_cost
Get Campaign Cost
stannp.get_account_balance
Get Account Balance
stannp.get_reporting_summary
Get Reporting Summary
stannp.get_campaign_available_dates
Get Campaign Available Dates
stannp.validate_address
Validate Address

write

Create and change things. Allow, or ask the user first.

stannp.create_group
Create recipient group
stannp.create_folder
Create folder
stannp.create_letter
Create Letter
stannp.create_campaign
Create Campaign
stannp.create_postcard
Create Postcard
stannp.create_selection
Create recipient selection
stannp.add_recipient_to_group
Add Recipient to Group
stannp.create_campaign_sample
Create campaign sample
stannp.add_recipients_to_group
Add recipients to group
stannp.upload_file
Upload File
stannp.import_recipients
Import Recipients
stannp.recalculate_group
Recalculate group

destructive

Delete, cancel or archive. Ask first, or deny outright.

stannp.delete_group
Delete recipient group
stannp.cancel_postcard
Cancel Postcard
stannp.delete_recipient
Delete Recipient
stannp.remove_recipients_from_group
Remove Recipients from Group
stannp.merge_pdfs
Merge PDF files
stannp.purge_group
Purge Group

03 · HOW IT WORKS

Stannp in three steps.

01Your users connect StannpThey add their Stannp api key on Arc0 Connect, under your brand. It goes straight into the vault.
02You set the rulesReads run, writes like “create recipient group” can wait for the user, and “delete recipient group” can be denied outright.
03Any agent can actYour agent calls Stannp through the Arc0 SDK or MCP, and so can Claude, ChatGPT and Cursor. Every call lands on the audit log.

POLICY.TS

await arc0.policies.set('stannp', {
  read: 'allow',
  write: 'ask',        // create_group
  destructive: 'deny',  // delete_group
})

# Claude Code: the same connection, one URL
$ claude mcp add --transport http arc0 \
    https://mcp.arc0.ai/u/u_8f2

04 · AUTH AND DATA

How Stannp connects.

Users add their Stannp api key on Arc0 Connect. It is encrypted in the vault, never shown to the model, and each user can rotate or revoke it at any time.

The same Stannp connection serves your agent over MCP and your own backend over REST and the proxy, so a user connects once. How Arc0 handles credentials →

AUTH: API key
CREDENTIALS: Per-tenant encrypted vault
MODEL SEES: Results only, never credentials
AUDIT LOG: Every call, on every plan

05 · WORKS WITH

Use Stannp from any agent.

Claude

ChatGPT

Cursor

Codex

VS Code

OpenAI Agents SDK

Claude Agent SDK

Vercel AI SDK

Mastra

LangGraph

06 · RELATED

More marketing apps.

Meta Ads67 actions

ActiveCampaign298 actions ActiveTrail159 actions

Adobe Marketing Agent12 actions

07 · FAQ

Stannp and Arc0, answered.

Q01

Can I use Stannp with Claude, ChatGPT or Cursor?

Yes. Connect Stannp to Arc0 once, then add your Arc0 MCP URL to Claude, ChatGPT, Cursor, Claude Code or any other remote-MCP client. Each assistant only gets the Stannp actions you allow.

Q02

How do users connect Stannp?

Users add their Stannp api key on Arc0 Connect. It is encrypted in the vault, never shown to the model, and each user can rotate or revoke it at any time.

Q03

Which Stannp actions can my agent take?

32 in total: 14 read, 12 write and 6 destructive, such as “create recipient group”. Your policies decide which of them each agent may call.

Q04

Can I stop my agent from deleting things in Stannp?

Yes. Actions like “delete recipient group” are graded destructive. Set destructive actions to deny, or to ask so the user approves each one, and blocked calls still show up on the audit log.

Q05

Can my own backend call Stannp too?

Yes. The same Stannp connection is available over REST and through the Arc0 proxy, so your product and your agent share one connection per user.

Get started

Plug Stannp into your agent.

Your users connect Stannp once, under your brand. Your agent gets 32 actions behind your policies, with every call on the record.

Connect Stannp Browse all apps →

Free to build · MCP + REST · Audit log on every plan