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.