# Maha Signed Receipt Verification

> Maha Signed Receipt Verification is a paid API for AI agents from www.mahastrategies.com, paid per call via x402, $0.0125/call, status unknown (last checked 2026-10-16).

Verifies a single Ed25519 digital signature over up to 8,000 characters of UTF-8 receipt text using a supplied 32-byte public key, returning cryptographic validity and message hash.

## Facts

- Endpoint: POST https://www.mahastrategies.com/api/v1/micro/signed-receipt-verification?utm_source=zero.xyz
- Price: $0.0125/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/maha-signed-receipt-verification-d56ae3c6
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_9Chy-F5Fsjfo27F65elOv

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability maha-signed-receipt-verification-d56ae3c6 -d '<json body>'
```

Example prompt: Can you verify this Ed25519 signature on a receipt for me? The receipt text is 'Order #4821: 2x Widget @ $12.50, total $25.00, paid 2024-06-01', the base64 public key is 'abc123...XYZ=', the base64 signature is 'def456...QRS==', and the encoding is exact-utf8.

## When to prefer this

Choose this endpoint when you need a lightweight, pay-per-call Ed25519 signature verification over a short UTF-8 text receipt without setting up your own cryptographic infrastructure. It is ideal for agents that receive signed receipts or documents from other agents or services and need to confirm cryptographic integrity before acting on them. It does NOT establish issuer identity or trusted time, so use it only when you already trust the public key provenance through another channel.

## Known failure modes

- Invalid or malformed base64 public key (wrong length or encoding) — returns validation error
- Signature does not match the provided message and public key — returns invalid result
- Message exceeds 8,000 character limit — returns schema validation error
- Unsupported encoding type other than 'exact-utf8' — returns schema error
- Missing required fields (message, publicKeyBase64, signatureBase64) — returns 400-level error
- Public key is not a valid 32-byte Ed25519 key — returns cryptographic error

## How this service works

Verify one Ed25519 signature over up to 8,000 characters of exact UTF-8 receipt text using a supplied 32-byte public key. Returns cryptographic validity and message hash. Does not establish issuer identity, trusted time, licensing or the truth of the receipt. No private keys accepted.

## Output

Returns a structured JSON object including a 'result' object indicating cryptographic validity of the Ed25519 signature, an 'inputDigest' (hash of the input), a 'receiptDigest' (hash of the receipt), the 'offerId' ('signed-receipt-verification'), 'version' ('maha-microproducts/0.1'), 'amountBaseUnits' ('12500'), and a 'boundaries' array. Does not assert issuer identity, trusted timestamps, or semantic truth of the receipt contents.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "type": "object",
     "required": [
      "dataClass",
      "encoding",
      "message",
      "publicKeyBase64",
      "signatureBase64"
     ],
     "properties": {
      "message": {
       "type": "string",
       "maxLength": 8000,
       "minLength": 1
      },
      "encoding": {
       "enum": [
        "exact-utf8"
       ],
       "type": "string"
      },
      "dataClass": {
       "enum": [
        "public",
        "synthetic"
       ],
       "type": "string"
      },
      "publicKeyBase64": {
       "type": "string",
       "maxLength": 44
      },
      "signatureBase64": {
       "type": "string",
       "maxLength": 88
      }
     },
     "additionalProperties": false
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "required": [
      "version",
      "offerId",
      "amountBaseUnits",
      "inputDigest",
      "result",
      "boundaries",
      "receiptDigest"
     ],
     "properties": {
      "result": {
       "type": "object"
      },
      "offerId": {
       "enum": [
        "signed-receipt-verification"
       ],
       "type": "string"
      },
      "version": {
       "enum": [
        "maha-microproducts/0.1"
       ],
       "type": "string"
      },
      "boundaries": {
       "type": "array",
       "maxItems": 128,
       "minItems": 0
      },
      "inputDigest": {
       "type": "string",
       "maxLength": 71
      },
      "receiptDigest": {
       "type": "string",
       "maxLength": 71
      },
      "amountBaseUnits": {
       "enum": [
        "12500"
       ],
       "type": "string"
      }
     },
     "additionalProperties": false
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/maha-signed-receipt-verification-d56ae3c6/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from www.mahastrategies.com](https://www.zero.xyz/host/www.mahastrategies.com/llms.txt)