What can you do with FabTally Decode?

FabTally Decode — MCP server

Developer on-chain decoding reads that turn raw EVM bytes into human-readable JSON — the capability buried inside $49-999/mo RPC plans. Fronts the Decode HTTP API at https://decode.fabtally.com. Holds no private key.

Tools (all paid; a call with no payment returns the decoded x402 402 challenge)

Tool	Price	What it does
`decode_log`	$0.003	Flagship. Decode event LOGS to JSON. `{chain, tx_hash}` decodes every log in a tx, or `{chain, address, topics[], data}` a single log; optional `abi`. Returns event name + canonical signature + named/typed args — handling tuple/array/nested params, anonymous events, indexed vs non-indexed. Resolves ABI via Sourcify/Blockscout + 4byte when none is given.
`decode_calldata`	$0.002	Decode a function call. `{chain, to?, data, abi?}` → selector resolved to a function signature (provided ABI / verified source / 4byte.directory) + fully decoded typed arguments.
`selector_lookup`	$0.001	Resolve a 4-byte function selector (`0x`+8 hex) or a 32-byte event topic (`0x`+64 hex) to human signature(s) via 4byte.directory + openchain.xyz, with a verified flag.
`abi_fetch`	$0.002	Fetch a contract's verified ABI + metadata (Sourcify/Blockscout) + verification status + full proxy-implementation resolution (EIP-1967/1822/OZ-legacy/beacon) — returns the implementation ABI for proxies. Args: `address`, `chain`.

Chains: ethereum, base, arbitrum, optimism, polygon, bsc.

Every tool also accepts an optional x_payment (base64 x402 payload) that is forwarded as the X-PAYMENT header to settle the call and return the real result. Humans can instead prepay by card and use an X-FabTally-Key credit key against the HTTP API.

Transports

stdio (portable): npx fabtally-decode-mcp (bin: fabtally-decode-mcp)
streamable-http (hosted): https://decode.fabtally.com/mcp

Config: FABTALLY_DECODE_BASE (default https://decode.fabtally.com).

Read-only, keyless, stateless, descriptive. Operated by Sunstone Soft (fabtally.com). Not a security guarantee or financial advice.

Install

Add FabTally Decode to your client. Pick the one you use.

claude mcp add --transport http fabtally-decode https://decode.fabtally.com/mcp

codex mcp add fabtally-decode --url https://decode.fabtally.com/mcp

{
  "mcpServers": {
    "fabtally-decode": {
      "url": "https://decode.fabtally.com/mcp"
    }
  }
}

Add to `~/.cursor/mcp.json`, or `.cursor/mcp.json` for a single project.

{
  "servers": {
    "fabtally-decode": {
      "type": "http",
      "url": "https://decode.fabtally.com/mcp"
    }
  }
}

Add to `.vscode/mcp.json` in your workspace.

{
  "mcpServers": {
    "fabtally-decode": {
      "url": "https://decode.fabtally.com/mcp"
    }
  }
}

Add to `claude_desktop_config.json`, then restart Claude Desktop.

{
  "mcpServers": {
    "fabtally-decode": {
      "serverUrl": "https://decode.fabtally.com/mcp"
    }
  }
}

Add to `~/.codeium/windsurf/mcp_config.json`.

4 tools

FabTally Decode exposes 4 tools to a connected agent.

decode_log: $0.003
decode_calldata: $0.002
selector_lookup: $0.001
abi_fetch: $0.002

Score

63 / 100

Good

Documentation16/25
Maintenance16/25
Trust13/20
Capability6/15
Install experience12/15

Documents what it does and how to connect
Has a resolvable package or endpoint
Exposes at least one tool, prompt or resource
README has substantive content
Includes a code example
Documents its configuration
Mentions credentials or security posture
Last commit 31 days ago
Has a release history
Repository is not archived
Licensed MIT
Namespace verified in the official MCP registry
Claimed by its owner
Published under an organisation
4 tool(s) documented
Provides prompt templates
Provides resources
6 documented install method(s)
Published to a package registry
Offers a hosted endpoint — no local install

Read the full rubric →

Version history

Versions	Published
1.0.0Latest	Aug 1, 2026