Handwrytten for AI agents

Handwrytten sends real handwritten notes using pen-holding robots, letting sales and marketing teams automate personal-feeling correspondence at scale for thank-yous, follow-ups, and gift enclosures. 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 Handwrytten See the 48 actions ↓

MarketingAPI keyMCP + RESThandwrytten.com

AUDIT LOG · HANDWRYTTENPOLICY: acme-support

09:41:07 · claude · u_8f2read

handwrytten.list_cards

List Cards✓ allowed · 212ms

09:41:08 · claude · u_8f2read

handwrytten.get_user

Get Current User Info✓ allowed · 164ms

09:41:09 · claude · u_8f2write

handwrytten.create_template

Create Template✓ approved · approved by user

09:41:12 · claude · u_8f2destructive

handwrytten.delete_template

Delete Template✕ blocked · policy: deny

EVERY HANDWRYTTEN CALL, ON THE RECORD

01 · USE CASES

What agents do in Handwrytten.

Add a recipient to the basket

Add a customer's mailing address to the order basket for an upcoming handwritten note run.

Pick a card and font

List available card designs and fonts to choose the right look for a campaign.

Review the basket before ordering

Review the current basket contents and taxes as a read-only check before the order is placed.

02 · ACTIONS

48 Handwrytten actions, graded by risk.

Every Handwrytten 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.

handwrytten.get_user
Get Current User Info
handwrytten.list_cards
List Cards
handwrytten.list_fonts
List Fonts
handwrytten.list_gcards
List Gift Cards
handwrytten.list_images
List Custom User Images
handwrytten.list_orders
List Orders
handwrytten.list_states
List States
handwrytten.list_baskets
List Past Baskets
handwrytten.list_inserts
List Inserts
handwrytten.list_countries
List Countries
handwrytten.list_templates
List Templates
handwrytten.get_basket_item
Get Basket Item
handwrytten.list_categories
List Categories
handwrytten.list_recipients
List Recipients
handwrytten.list_signatures
List Signatures
handwrytten.get_basket_count
Get Basket Count

+ 14 MORE

write

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

handwrytten.add_recipient
Add Recipient
handwrytten.update_basket
Update Basket Item
handwrytten.create_template
Create Template
handwrytten.update_template
Update Template
handwrytten.update_recipient
Update Recipient
handwrytten.create_user_address
Create User Address
handwrytten.update_billing_info
Update Billing Information
handwrytten.logout
Logout User
handwrytten.place_basket
Place Order in Basket
handwrytten.register_user
Register User
handwrytten.set_test_mode
Set Test Mode
handwrytten.upload_custom_logo
Upload Custom Logo
handwrytten.set_default_address
Set Default Address

destructive

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

handwrytten.delete_template
Delete Template
handwrytten.delete_recipient
Delete Recipient Address
handwrytten.delete_custom_image
Delete Custom Image
handwrytten.clear_basket
Clear Basket
handwrytten.request_reset_password
Request Password Reset

03 · HOW IT WORKS

Handwrytten in three steps.

01Your users connect HandwryttenThey add their Handwrytten api key on Arc0 Connect, under your brand. It goes straight into the vault.
02You set the rulesReads run, writes like “create Template” can wait for the user, and “delete Template” can be denied outright.
03Any agent can actYour agent calls Handwrytten 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('handwrytten', {
  read: 'allow',
  write: 'ask',        // create_template
  destructive: 'deny',  // delete_template
})

# 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 Handwrytten connects.

Users add their Handwrytten 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 Handwrytten 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 Handwrytten 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

Handwrytten and Arc0, answered.

Q01

Can I use Handwrytten with Claude, ChatGPT or Cursor?

Yes. Connect Handwrytten 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 Handwrytten actions you allow.

Q02

How do users connect Handwrytten?

Users add their Handwrytten 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 Handwrytten actions can my agent take?

48 in total: 30 read, 13 write and 5 destructive, such as “create Template”. Your policies decide which of them each agent may call.

Q04

Can I stop my agent from deleting things in Handwrytten?

Yes. Actions like “delete Template” 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 Handwrytten too?

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

Get started

Plug Handwrytten into your agent.

Your users connect Handwrytten once, under your brand. Your agent gets 48 actions behind your policies, with every call on the record.

Connect Handwrytten Browse all apps →

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