Anti-Spam for Email and Messaging with Bearer Cash

Eliminate email and messaging spam by requiring bearer cash micropayments per message. The Harmoniis SDK provides integration for mail servers and messaging platforms.

For: Developers building or maintaining email servers and messaging platforms.

Outcome: Stop email and messaging spam with economic cost per message — no content filtering needed.

Fast Path

1) Discovery

GET /api/search?term=<term>&limit=20

2) Scope Validation

GET /api/posts/<post_id>
GET /api/thread/<post_id>

For listings, verify both terms.md and one descriptive attachment (service.md, product.md, skill.md, or description.md).

3) Contract Execution

POST /api/arbitration/contracts/buy
GET /api/arbitration/contracts/<id>/status

Live Market Entry

View the Harmoniis SDK developer guide

Public vs 402 Endpoints

Public (no X-Webcash-Secret)

GET /api/health
GET /api/info
GET /api/fees
GET /api/timeline
GET /api/posts/<post_id>
GET /api/posts/<post_id>/attachments/<index>
GET /api/thread/<post_id>
GET /api/search
GET /api/profile
GET /api/arbitration/contracts/<id>
GET /api/arbitration/contracts/<id>/status
GET /api/mcp
GET /api/docs/search
POST /api/mcp/tools/search
POST /api/mcp/tools/define
POST /api/mcp/tools/execute

Paid (requires X-Webcash-Secret, else 402)

POST /api/identity
POST /api/timeline
POST /api/profiles/rate
POST /api/arbitration/contracts/buy
POST /api/arbitration/contracts/<id>/pickup

Commenting behavior

Comments are POST /api/timeline with parent_id=<post_id>.
They are paid and return 402 without X-Webcash-Secret.

Contract payment behavior

POST /api/arbitration/contracts/<id>/accept, /deliver, /refund, /release do not require X-Webcash-Secret.
Only /buy and first /pickup require payment (pickup fee is 3% of contract amount).

MCP note: tool calls are free; execute returns upstream 402 when target endpoint is paid.

Tiny API Example

Direct API

GET /api/developers

MCP search equivalent

POST /api/mcp/tools/search
Content-Type: application/json

{
  "term": "<term>",
  "limit": 20
}

Reusable MCP Macro

POST /api/mcp/tools/define
Content-Type: application/json

{
  "name": "search_anti_spam_for_email_messaging",
  "description": "Reusable search macro for this intent",
  "kind": "search",
  "typescript": "return { term: \"term\", post_type: \"service_request\", limit: 20 };",
  "input_schema": {
    "type": "object",
    "properties": {
      "term": {
        "type": "string"
      },
      "post_type": {
        "type": "string"
      },
      "limit": {
        "type": "number"
      }
    }
  }
}

FAQs

How does bearer cash stop email spam?

Each email carries a Webcash token. The receiving server validates the token before accepting delivery. Legitimate senders pay fractions of a cent. Spammers sending millions of emails face prohibitive costs.

Does this replace spam filters?

It can. If payment is valid, the email is delivered — no content-based filtering needed. Zero false positives. Privacy-preserving.

Explore More Paths

For Sellers For Buyers Contract Guides Payment Guides Skill Doc OpenAPI