Base64 Codec API

Encode text to base64 or decode base64 to text. Supports standard and URL-safe variants with metadata. Pay-per-call via x402 (USDC on Base L2) -- no API key, no signup, no rate-limit wall.

Part of the klymax402 marketplace -- 100 x402 micropayment APIs for AI agents, one wallet, USDC on Base.

Quickstart -- MCP

Add to your MCP client config (Claude Desktop, Cursor, ElizaOS, etc.):

{
  "mcpServers": {
    "base64-codec": {
      "url": "https://base64-codec.api.klymax402.com/mcp"
    }
  }
}

Quickstart -- HTTP (x402)

curl -X POST "https://base64-codec.api.klymax402.com/api/encode" \
  -H "Content-Type: application/json" \
  -d '{"data":"..."}'
# -> 402 Payment Required, with an x402 payment challenge in the response body

Any x402-aware client (@x402/fetch, x402-agent-tools, ATXP) handles the 402 -> sign -> retry cycle automatically.

Tools

Tool	Method	Path	Price	Description
utility_encode_base64	POST	/api/encode	$0.003	Encode or decode base64 data

utility_encode_base64

Use this when you need to encode text to base64 or decode base64 back to plaintext. Returns the result string with encoding metadata.

Parameters

Name	Type	Required	Description
data	string	yes	The data to encode or decode
action	string	no	Action: 'encode' or 'decode' (default: encode)

Example response:

{"result":"SGVsbG8gV29ybGQ=","action":"encode","inputLength":11,"outputLength":16,"urlSafe":false}

When to use: embedding binary data in JSON, preparing email attachments (MIME), or decoding base64 tokens from APIs. Use this BEFORE sending data through channels that only support ASCII.

Not for: hashing (use crypto_generate_hash), JWT decoding (use security_decode_jwt), URL slug creation (use text_generate_slug).

Example agent prompts

• "Encode text to base64 or decode base64 back to plaintext"

Payment

• Protocol: x402 -- HTTP-native pay-per-call, no signup, no API key
• Network: Base L2 (eip155:8453)
• Asset: USDC
• Facilitator: Coinbase CDP (primary), PayAI (fallback)
• Also reachable via ATXP (OAuth-wrapped x402, RFC 9728 protected-resource metadata)

Part of klymax402

100 x402 micropayment APIs for AI agents -- one wallet, USDC on Base, zero signup.

• Catalog: https://klymax402.com/llms.txt
• Full API reference: https://klymax402.com/llms-full.txt
• Live stats: https://klymax402.com/stats

License

MIT