x402 · MCP · SKILL.md

Agent rail: add credits, then rent

AI agents add credits with USDC on Base (x402), get a uc_live API key, then rent a Ucode number and poll until one SMS arrives. You can also pay per SMS. No human dashboard required. Lawful verification, QA, travel, and privacy only—not bulk account farming. If SMS never arrives, credits refund automatically.

Install the Ucode MCP server

One URL for every assistant: https://mcp.ucodesim.com/mcp (streamable HTTP). Browsing numbers and prices needs no login — ask “is there a UK number for Telegram and how much?”. To rent, people sign in with a free Ucode account from the chat; agents pay USDC on Base.

Add to Cursor Add to VS Code

# Claude (claude.ai / Desktop): Settings → Connectors → Add custom connector
#   URL: https://mcp.ucodesim.com/mcp
# Claude Code
claude mcp add --transport http ucode https://mcp.ucodesim.com/mcp
# ChatGPT: Settings → Apps & Connectors → Create → MCP URL above
# Codex CLI (~/.codex/config.toml)
[mcp_servers.ucode]
url = "https://mcp.ucodesim.com/mcp"
# Gemini CLI
gemini mcp add --transport http ucode https://mcp.ucodesim.com/mcp
# Agents with a wallet: send Authorization: Bearer uc_live_… to reuse credits

How paying works

  • People: ask the assistant to sign you in (ucode_login_start), buy credits by card, Apple Pay or crypto at /app/credits, then rent in the chat (ucode_sms_rent_with_credits). Credits never expire.
  • Autonomous agents: ucode_agent_billing → ucode_agent_buy_credits returns an x402 quote → sign USDC on Base → call again with paymentHeader → credits + uc_live_ key → ucode_agent_rent → ucode_agent_check_sms. Or pay per SMS with ucode_agent_rent.
  • No SMS? Credits refund automatically.

Add credits (REST)

This is how agents charge their account. Packs and USDC prices are the same credit packages as the panel (not a separate agent price list). Humans use /app/credits instead.

GET  https://app-api.ucodesim.com/api/v1/agent/credits
POST https://app-api.ucodesim.com/api/v1/agent/credits
{ "pack":"PACKAGE_ID", "acceptLawfulUse":true }

# HTTP 402 → pay USDC on Base → retry with X-PAYMENT
# Save data.apiKey (shown once)
GET  https://app-api.ucodesim.com/api/v1/agent/me   # Bearer uc_live_…

Discover

GET  https://app-api.ucodesim.com/api/v1/agent
GET  https://app-api.ucodesim.com/.well-known/x402
GET  https://ucode.uk/.well-known/x402
Skill: https://ucode.uk/agents/SKILL.md
MCP:  https://mcp.ucodesim.com/mcp  (tool: ucode_agent_billing)

Rent

POST /api/v1/agent/activations
{ "service":"wa", "country":0, "purpose":"qa", "acceptLawfulUse":true }

# Prepaid: Authorization: Bearer uc_live_…
# Or pay-per-SMS: HTTP 402 → USDC on Base → retry with X-PAYMENT

Wait

Poll data.pollUrl every 3–5 seconds until data.sms is set, or the rental is cancelled/refunded (~20 minutes). Failed SMS refunds credits, not on-chain USDC.

Links

purpose must be qa, privacy, travel, or business. Do not use this to create bulk or fake accounts.

Humans: ucode.uk · Add credits. REST keys: /api. Policy: termsDMCA.

FAQ

How do agents add credits?

GET /api/v1/agent/credits (same packs and prices as the panel), POST that packageId, pay the 402 quote in USDC on Base, save the uc_live API key. ChatGPT humans use ucode.uk/app/credits.

Do agents need a Ucode login?

Not if they pay x402. Prepaid issues a uc_live key once. They can also send an existing key.

What if SMS never arrives?

Automatic credit refund, same as the apps. On-chain USDC is not returned. Do not retry-spam.

Which chain is x402 on?

USDC on Base.

Where is the skill file?

https://ucode.uk/agents/SKILL.md

Download FreeOpen Ucode Web