PostBridge AI
Try Free with ChatGPT
Five Countries Zero Signup Required Cryptographic Proof MCP + Agent Native Free to Try

AI Handles the Workflow.
PostBridge Handles the Mail.

PostBridge is postal infrastructure for AI agents and the professionals they serve. Send certified letters in five countries from ChatGPT, your agent, or the API. Pay per letter. No subscription.

Try Free with ChatGPT Developer Hub

Free to try · No account needed · Real letters in 1-5 business days

The missing layer

AI agents can do almost everything. Almost.

They execute trades, draft contracts, summarize case files, and process payments autonomously. But when a workflow requires a certified letter, the chain breaks. Someone still has to print, sign, and mail it manually.

Certified mail is still manual

Law firms send dozens of demand notices weekly. Every one requires someone to leave their desk.

Dispute letters are a bottleneck

Credit repair workflows are automated end-to-end except the part that matters most to bureaus.

Agents stop at the physical layer

Your agent can pay, book meetings, and file workflows. It cannot send a certified letter. Until now.

The solution

PostBridge bridges AI workflows and the physical world.

A ChatGPT app, API, and MCP server that let AI agents, automations, and professionals send verified physical mail to addresses in the US, UK, France, Germany, and Canada.

Cryptographic Proof

Every letter generates a signed W3C Verifiable Credential. Tamper-proof and independently verifiable.

Native to agent frameworks

x402, MCP, AgentKit, ElizaOS, LangChain, CrewAI. If your agent can make an HTTP call, it can send mail.

Pay per letter

No subscription and no minimum commitment. Use ChatGPT, card checkout, or agent-native payment flows.

How it works

Two ways to get started.

Whether you use ChatGPT or build AI agents, PostBridge is designed to get your first letter out in under 5 minutes.

For Professionals

1

Open the ChatGPT app

No account needed. Open the PostBridge Mailer directly in ChatGPT.

2

Describe or upload your document

Paste your letter text, describe what you need, or upload a PDF.

3

PostBridge handles the rest

Your letter ships within the service window. You get tracking and proof.

Try the ChatGPT App Free

Works in ChatGPT · Free to try · Postage paid at checkout

For Developers

1

Pick your integration path

Use x402, UCAN, or a traditional API key depending on your agent stack.

2

Quote, confirm, then send

Agents should quote first and call send only after explicit confirmation.

3

Receive proof

Track delivery and retrieve signed proof for compliance workflows.

send.http
POST https://api.postbridge.ai/api/orders
Authorization: Bearer pb_live_...
Content-Type: application/json

{
  "to_name": "Jane Smith",
  "to_line1": "123 Main St",
  "to_city": "New York",
  "to_country": "US",
  "from_country": "US",
  "service": "us_certified",
  "document_url": "https://your-cdn.com/letter.pdf"
}
Open the Developer Hub
Use cases

Built for workflows where mail has legal weight.

Law Firms

Automate demand notices, certified correspondence, and compliance letters.

legal_compliance

Real Estate

Send disclosures, notices, and agreements with registered mail and delivery confirmation.

transactional

Accounting Firms

Time-sensitive tax correspondence and client notices with proof your compliance team can file.

regulatory_filing

Credit Repair

Scale dispute-letter workflows without scaling manual mail operations.

certified mail

Marketing Mail Campaigns

Automate and scale your mailing campaign workflows.

MCP / API

AI Agent Developers

Add the physical mail layer your agent workflow is missing. One API, five countries.

MCP / API / x402
Integrations

Works with every agent platform.

Native paths across crypto-native and traditional agent frameworks, with technical details moved to the developer hub.

ClaudeMCP server config
Coinbase AgentKitx402 USDC
ElizaOSMCP plugin
Fetch.ai / ASIAgent workflows
Olas MechAgent marketplace
Virtuals ACPBase L2 commerce
LangChain + CrewAIPython wrappers
OpenAI GPT ActionsOpenAPI spec
Five Countries 15+ Postal Services 8 Agent Platforms
Trust and compliance

Every letter is cryptographically signed.

PostBridge issues signed proof artifacts for dispatched letters, so compliance teams and counterparties can verify delivery evidence without trusting a screenshot.

Sovereign Agent Identity

Agent identity can be DID-backed, globally unique, and portable across workflows.

Proof You Can Present

Postal proof and delivery proof are designed for independent verification.

Data Handling

Documents are staged for fulfillment and are not used to train models.

Pricing

Pay per letter. No subscription. No minimums.

PostBridge prices each letter at quote time. Crypto-native flows and traditional checkout both stay pay-per-letter.

Best Price

Crypto

x402 / USDC / Lightning

Pay per letter

No subscription. Best price.

  • Zero signup flow
  • Payment can authorize the request
  • No subscription
  • Quote before send
  • Proof included
Get Started

Fiat

Card checkout · USD / EUR / CAD

Pay per letter

Card checkout. No subscription.

  • Email signup flow
  • Card payment via checkout
  • Confirmation email
  • Tracking link
  • Proof included
Try with ChatGPT

Quotes come from the API before a letter is sent. Developer pricing details live in the developer hub.

For developers

Add postal to your agent in minutes.

PostBridge exposes an API, MCP server, Python wrappers, and an OpenAPI contract for agent platforms. Pick your integration path and send your first letter after quote and confirmation.

Open the Developer Hub
minimal-agent-send.http
# Quote first. Send only after confirmation.
POST https://api.postbridge.ai/api/orders
Authorization: Bearer pb_live_...

{
  "to_name": "Jane Smith",
  "to_line1": "123 Main St",
  "to_city": "New York",
  "to_country": "US",
  "from_country": "US",
  "service": "us_certified",
  "document_url": "https://your-cdn.com/letter.pdf"
}

# Response: letter_id, tracking, proof

Send your first letter today. It is free to try.

Open the PostBridge Mailer in ChatGPT. No signup, no account. Or explore the full developer platform.

Try Free with ChatGPT Developer Hub

Real letters · five countries · delivery in 1-5 business days · cryptographic proof included