FabTally Decode
REMOTE · DECODE.FABTALLY.COM · SCANNED SEP 20
Decode EVM bytes to JSON: event-log decoder, calldata explainer, selector lookup, ABI fetch.
Available components
How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. How we score → Why this is hard to score →
Endpoint Security57
- The endpoint's TLS certificate is valid, in date, and uses a strong key. View diagnostics → Pass
- Authorisation not fully verified: no authorisation is required to call this server, and 4 tool(s) never declared a destructiveHint. The MCP spec treats an absent hint as destructive by default, so we cannot call this surface safe. See how to fix → View diagnostics → Unverified
- HTTPS is enforced; there's no plaintext access path. View diagnostics → Pass
- HSTS check failed: the Strict-Transport-Security header is absent. See how to fix → View diagnostics → Fail
- DNSSEC check failed: this domain isn't protected by DNSSEC. See how to fix → View diagnostics → Fail
Transport & Reachability100
- Verified streamable-http transport via a live MCP handshake. View diagnostics → Pass
Schema Quality & AI Usability68
- AI-judged instruction clarity (excellent).Pass
- Context-footprint check failed: tool/resource definitions use about 1009 tokens (~252/item across 4 items; 4 tools + 0 resources), over budget; trim descriptions and params. See how to fix → Fail
- Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management100
- No destabilizing schema changes in the last 30 days.Pass
Tool Coverage100
- 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
- 100% of tool parameters carry a description.Pass
Tool Safety100
- No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
- We read all 4 captured tool definition(s), and no name or description among them implies an irreversible operation.Pass
- An AI judge read all 4 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities100
- Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.Pass
How do I install the FabTally Decode MCP server?
FabTally Decode is a hosted endpoint at https://decode.fabtally.com/mcp, so there is nothing to install locally. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.
remote · decode.fabtally.com
claude mcp add --transport http zvmzaretsky-onchain-decode 'https://decode.fabtally.com/mcp'
{
"mcpServers": {
"zvmzaretsky-onchain-decode": {
"url": "https://decode.fabtally.com/mcp"
}
}
} {
"servers": {
"zvmzaretsky-onchain-decode": {
"type": "http",
"url": "https://decode.fabtally.com/mcp"
}
}
} [mcp_servers.zvmzaretsky-onchain-decode] url = "https://decode.fabtally.com/mcp"
{
"$schema": "https://opencode.ai/config.json",
"mcp": {
"zvmzaretsky-onchain-decode": {
"type": "remote",
"url": "https://decode.fabtally.com/mcp",
"enabled": true
}
}
} openclaw mcp add zvmzaretsky-onchain-decode --url 'https://decode.fabtally.com/mcp' --transport streamable-http
mcp_servers:
zvmzaretsky-onchain-decode:
url: "https://decode.fabtally.com/mcp" {
"McpServers": {
"zvmzaretsky-onchain-decode": {
"Transport": "http",
"Url": "https://decode.fabtally.com/mcp"
}
}
} assistant mcp add zvmzaretsky-onchain-decode -t streamable-http -u 'https://decode.fabtally.com/mcp'
{
"mcpServers": {
"zvmzaretsky-onchain-decode": {
"type": "http",
"url": "https://decode.fabtally.com/mcp"
}
}
} The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.
Every change we have recorded for this component, newest first. Security-relevant changes are always shown. ▲ marks a change for the better, ▼ a change for the worse; unmarked changes are neutral.
- 31 Aug 26 0
- Stability: 0.97 → pass security
- 30 Aug 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 93 to 97. That category is still filling its 30-day observation window: 28 days of observed history at the previous scan, 29 at this one. The score rises as the window fills, whether or not the server changes.
- 28 Aug 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 87 to 90. That category is still filling its 30-day observation window: 26 days of observed history at the previous scan, 27 at this one. The score rises as the window fills, whether or not the server changes.
- 26 Aug 26 +2
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 24 Aug 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 73 to 77. That category is still filling its 30-day observation window: 22 days of observed history at the previous scan, 23 at this one. The score rises as the window fills, whether or not the server changes.
- 11 Aug 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 2 Aug 26 0
- Stability: unverified → 0.03 ▲ functional
- 1 Aug 26 0
First indexed and scored.
Diagnostic detail from the automated scan of this channel: what the scanner observed at each step, so you can see exactly where a check passed or failed. It is informational only and never changes the trust score.
Captured 20 Sept 2026 · Probed https://decode.fabtally.com/mcp
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=decode.fabtally.com | CN=YR2,O=Let's Encrypt,C=US | 1 Aug 2026 | 30 Oct 2026 | RSA 2048 | SHA256-RSA | 59af41441ec330c8d95572c3169308774fd |
| SANs: decode.fabtally.com | ||||||
| CN=YR2,O=Let's Encrypt,C=US (CA) | CN=Root YR,O=ISRG,C=US | 3 Sept 2025 | 2 Sept 2028 | RSA 2048 | SHA256-RSA | 4ebd24947e24d394802d84a52fd5b319 |
| CN=Root YR,O=ISRG,C=US (CA) | CN=ISRG Root X1,O=Internet Security Research Group,C=US | 13 May 2026 | 2 Sept 2032 | RSA 4096 | SHA256-RSA | f24b6d17f9d9ad7cb1c9fea78782699f |
Background: What to check on a remote MCP endpoint →
DNSSEC insecure
Validation of decode.fabtally.com. — Not signed
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | trust_anchor | 20326, 38696 | 8, 8 | Verified |
| com. | present | 19718 | 13 | Verified |
| fabtally.com. | absent | Unsigned (proven) parent-signed NSEC/NSEC3 proves an unsigned delegation |
Authentication No authorisation required
The endpoint answered without asking for a token. Anyone who knows the URL can reach it.
| Result | No authorisation required |
|---|---|
| HTTP status | 200 |
Background: How OAuth 2.1 works in the 2026 MCP spec →
Transports 2 probes
| Transport | URL | Outcome | Status | Location |
|---|---|---|---|---|
| streamable-http | https://decode.fabtally.com/mcp | Verified | 200 | |
| http (plaintext) | http://decode.fabtally.com/mcp | HTTPS enforced | 301 | https://decode.fabtally.com/mcp |
The tools this component advertises to a client, with an estimated token cost for each. Expand a tool to see its parameters and schema. The per-tool counts are indicative and are not scored directly; the schema's total context footprint is one signal in Schema Quality & AI Usability. A tool's description is untrusted text the model reads on every call, which is what makes this list a security surface and not just an inventory: how tool poisoning works →
abi_fetch Fetch a contract's verified ABI + proxy resolution (paid $0.002) ~208
PAID $0.002 (x402, USDC on Base). Fetch the verified ABI + metadata for a contract. Give {address, chain}; get the ABI JSON, verification status/source (Sourcify or Blockscout), the callable function/event signatures, and full proxy-implementation resolution (EIP-1967/1822/OZ-legacy/beacon) — returning the implementation's ABI when it's a proxy. Without payment returns the x402 challenge; pass x_payment to settle.
| Name | Type | Req | Description |
|---|---|---|---|
| address | string | yes | Contract address (0x + 40 hex). |
| chain | string | yes | EVM chain: ethereum | base | arbitrum | optimism | polygon | bsc. |
| x_payment | string | – | x402 payment payload (base64) for this PAID decode. If supplied it is forwarded as the X-PAYMENT header to settle the call and return the real result instead of a 402 challenge. Omit to get the price… |
No output schema declared.
No examples provided.
decode_calldata Decode a function call's calldata (paid $0.002) ~255
PAID $0.002 (x402, USDC on Base). Decode a contract function call. Give {chain, to?, data, abi?}; get the 4-byte selector resolved to a function signature (via provided ABI, the verified contract source, or 4byte.directory) plus fully decoded, typed arguments (tuples/arrays/nested included). Without payment returns the x402 challenge.
| Name | Type | Req | Description |
|---|---|---|---|
| abi | – | – | Optional contract ABI (JSON array or JSON string). If omitted, the ABI is resolved from the verified source (Sourcify/Blockscout) or 4byte.directory. |
| chain | string | yes | EVM chain: ethereum | base | arbitrum | optimism | polygon | bsc. |
| data | string | yes | Calldata (0x hex, at least the 4-byte selector). |
| to | string | – | Contract address the call targets (optional; enables verified-ABI resolution). |
| x_payment | string | – | x402 payment payload (base64) for this PAID decode. If supplied it is forwarded as the X-PAYMENT header to settle the call and return the real result instead of a 402 challenge. Omit to get the price… |
No output schema declared.
No examples provided.
decode_log Decode event logs to typed JSON (paid $0.003) ~354
PAID $0.003 (x402, USDC on Base). FLAGSHIP: decode EVM event LOGS to human-readable JSON. Give {chain, tx_hash} to decode every log in a transaction, OR {chain, address, topics[], data} for a single log; optional {abi}. Returns each event's name, canonical signature and named/typed args — correctly handling tuple/array/nested params, anonymous events, and indexed vs non-indexed. Resolves the ABI via Sourcify/Blockscout + 4byte event signatures when none is supplied. Without payment returns the x402 challenge; pass x_payment to settle.
| Name | Type | Req | Description |
|---|---|---|---|
| abi | – | – | Optional contract ABI (JSON array or JSON string). If omitted, the ABI is resolved from the verified source (Sourcify/Blockscout) or 4byte.directory. |
| address | string | – | Contract address of a single log (used with topics + data). |
| chain | string | yes | EVM chain: ethereum | base | arbitrum | optimism | polygon | bsc. |
| data | string | – | Log data field (0x hex) holding the non-indexed args. |
| topics | array | – | Log topics array (topic0 is the event signature hash for non-anonymous events). |
| tx_hash | string | – | Transaction hash (0x + 64 hex) — decodes every event log in the tx. |
| x_payment | string | – | x402 payment payload (base64) for this PAID decode. If supplied it is forwarded as the X-PAYMENT header to settle the call and return the real result instead of a 402 challenge. Omit to get the price… |
No output schema declared.
No examples provided.
selector_lookup Resolve a selector or event topic to a signature (paid $0.001) ~192
PAID $0.001 (x402, USDC on Base). Resolve a 4-byte function selector (0x + 8 hex) OR a 32-byte event topic hash (0x + 64 hex) to its human-readable signature(s) via 4byte.directory + openchain.xyz. Returns all matches (selectors can collide) with a verified flag. Without payment returns the x402 challenge; pass x_payment to settle.
| Name | Type | Req | Description |
|---|---|---|---|
| selector | string | yes | A 4-byte function selector (0x + 8 hex) or a 32-byte event topic hash (0x + 64 hex). |
| x_payment | string | – | x402 payment payload (base64) for this PAID decode. If supplied it is forwarded as the X-PAYMENT header to settle the call and return the real result instead of a 402 challenge. Omit to get the price… |
No output schema declared.
No examples provided.
What is the FabTally Decode MCP server?
FabTally Decode is an MCP server listed in the public MCP registry as io.github.zvmzaretsky/onchain-decode. Decode EVM bytes to JSON: event-log decoder, calldata explainer, selector lookup, ABI fetch. This page covers its hosted endpoint (https://decode.fabtally.com/mcp).
Is the FabTally Decode MCP server safe to use?
FabTally Decode scores 77 out of 100 on VerifyMCP. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.
What tools does the FabTally Decode MCP server expose?
FabTally Decode exposes 4 tools: decode_log, decode_calldata, selector_lookup, abi_fetch. Their descriptions and schemas cost roughly 1,009 tokens of context every time the server is loaded.
Does the FabTally Decode MCP server require authentication?
No. We connected to FabTally Decode without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.
Is the FabTally Decode MCP server still maintained?
FabTally Decode is still listed as active in the MCP registry. We last reached this channel on 20 September 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.