Solana Priority Fee Estimator API

MCP Server x402 License: MIT

Solana priority fee estimates at 6 levels (min to max). Essential for every Solana transaction. 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": {
    "solana-fees": {
      "url": "https://solana-fees.api.klymax402.com/mcp"
    }
  }
}

Quickstart -- HTTP (x402)

curl "https://solana-fees.api.klymax402.com/api/fees"
# -> 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
solana_get_priority_fees	GET	/api/fees	$0.001	Priority fee estimates for Solana transactions

solana_get_priority_fees

Use this when you need priority fee estimates before sending a Solana transaction. Returns recommended compute unit prices at 6 levels based on recent network activity.

Parameters

Name	Type	Required	Description
program	string	no	Program ID to get program-specific fees (e.g. JUP6LkbZbjS1jKKwapdHNy74zcZ3tLUZoi5QNyVTaV4 for Jupiter). Optional — omit for global fees.

Returns

• fees -- object with 6 fee levels in microlamports per compute unit
• min -- minimum fee observed (cheapest, may fail in congestion)
• low -- 25th percentile fee (budget transactions)
• medium -- 50th percentile fee (recommended default)
• high -- 75th percentile fee (fast confirmation)
• veryHigh -- 90th percentile fee (priority during congestion)
• max -- maximum fee observed (guaranteed fast)

Example response:

{"fees":{"min":1,"low":100,"medium":1000,"high":5000,"veryHigh":50000,"max":500000},"slot":285432100,"program":"global","updatedAt":"2026-04-13T12:00:00Z"}

When to use: every Solana transaction to set the right priority fee. Essential for Jupiter swaps, NFT mints, token transfers, and program interactions.

Example agent prompts

• "Priority fee estimates before sending a Solana transaction"

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