Arabic Pipeline API MCP server

Arabic Pipeline API

Pay-per-call utilities for Arabic text, audio and documents, sold over x402 in USDC on Base.

No API key. No account. No subscription. The first request returns 402 Payment Required; the client signs a payment and retries; the money lands in the provider's wallet. That is the whole protocol — and it is why this service can pay a provider directly, with no payment processor in between.

url https://payapi.market/mcp

Live endpoints

The MCP server exposes the same four capabilities as tools, each behind its own x402 payment (textmetrics, textnormalize, audiotranscribe, docextract).

Endpoints

POST /text/normalize accepts a mode:

• light — lossless: whitespace, digit unification, bidi cleanup only.
• search — light + tashkeel removal + letter folding (أإآ→ا, ى→ي, ة→ه).
• index — search + punctuation stripped (use as a dedup / index key).

Try it

# 1. Any paid route answers 402 with a payment challenge
curl -i https://arabic-pipeline.arabic-pipeline.workers.dev/text/normalize \
  -H 'content-type: application/json' \
  -d '{"text":"مُحَمَّدٌ عَلِيّ","mode":"search"}'

# 2. Free routes (no payment needed)
curl https://arabic-pipeline.arabic-pipeline.workers.dev/openapi.json
curl https://arabic-pipeline.arabic-pipeline.workers.dev/

How x402 payment works (for agents)

accepts[] entries describing how to pay (network, asset, price, payTo).

1. Call the route with no payment header → 402 Payment Required.
2. The response carries a base64 PAYMENT-REQUIRED header and, in the body,

PAYMENT-SIGNATURE header (base64 payment payload).

1. Pick one entry, sign a payment for it, and retry the request with the

returns the real result plus a PAYMENT-RESPONSE header with the receipt.

1. The server verifies and settles the payment (via the facilitator) and

The full machine-readable contract — including per-operation x-payment-info — is at GET /openapi.json.

Settlement

(0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913).

• Network: Base mainnet (eip155:8453), asset USDC

(https://x402.dexter.cash — no account, no fees). The facilitator only executes the buyer's signed payment; it never holds funds.

• Payments are verified and settled by a public x402 facilitator

• Settlement destination: 0x05523af5bd166816D1418Ebf7D6371e1fFB1D2e6.

Model endpoints

/audio/transcribe uses gemini-3.5-transcribe; /doc/extract uses gemini-3.6-flash with a JSON response schema. Both model names are configurable (GEMINITRANSCRIBEMODEL, GEMINIVISIONMODEL). The two text endpoints are pure computation and cost nothing to serve.

Local development

Shortened. The full README is on GitHub.