# TxWhy (remote · txwhy.vercel.app)

Failed Solana transaction in, working transaction out. Exact cause, rebuilt tx, verifiable repair.

- Trust score: 74/100 (medium)
- Change this week: +3
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-10-22

## Components

- remote · `txwhy.vercel.app`: 74/100 (this document), [markdown](https://verifymcp.io/servers/sundram07-txwhy/api-mcp.md), [page](https://verifymcp.io/servers/sundram07-txwhy/api-mcp)

## Channel facts

- Endpoint: `https://txwhy.vercel.app/api/mcp`
- Transports: `streamable-http`
- Auth: `none`
- Version: `0.2.0`

## Trust breakdown

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. Scores are 0–100 per category. Scoring method: https://verifymcp.io/docs/scoring (what has changed: https://verifymcp.io/docs/scoring/changelog)

Scored 2026-10-22.

- **Endpoint Security**: 63/100
  - The endpoint's TLS certificate is valid, in date, and uses a strong key.
  - Authorisation not fully verified: no authorisation is required to call this server, and 3 tool(s) never declared a destructiveHint. The MCP spec treats an absent hint as destructive by default, so we cannot call this surface safe.
  - HTTPS is enforced; there's no plaintext access path.
  - The HSTS (Strict-Transport-Security) header is present.
  - DNSSEC check failed: this domain isn't protected by DNSSEC.
- **Transport & Reachability**: 100/100
  - Verified streamable-http transport via a live MCP handshake.
- **Schema Quality & AI Usability**: 81/100
  - AI-judged instruction clarity (excellent).
  - Context-footprint check failed: tool/resource definitions use about 441 tokens (~147/item across 3 items; 3 tools + 0 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 43/100
  - Stability observed for 13 of 30 days with no destabilising changes; credit accrues until the full window elapses.
- **Tool Coverage**: 100/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 100% of tool parameters carry a description.
- **Tool Safety**: 100/100
  - No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.
  - We read all 3 captured tool definition(s), and no name or description among them implies an irreversible operation.
  - An AI judge read all 3 captured unit(s) of tool text and found none that tries to manipulate the model reading it.
- **Capabilities**: 100/100
  - Implements a current MCP spec version (2026-07-28).

## Install

### How do I install the TxWhy MCP server?

TxWhy is a hosted endpoint at https://txwhy.vercel.app/api/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.

### Claude

```bash
claude mcp add --transport http sundram07-txwhy 'https://txwhy.vercel.app/api/mcp'
```

### Cursor

```json
{
  "mcpServers": {
    "sundram07-txwhy": {
      "url": "https://txwhy.vercel.app/api/mcp"
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "sundram07-txwhy": {
      "type": "http",
      "url": "https://txwhy.vercel.app/api/mcp"
    }
  }
}
```

### Codex

```toml
[mcp_servers.sundram07-txwhy]
url = "https://txwhy.vercel.app/api/mcp"
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "sundram07-txwhy": {
      "type": "remote",
      "url": "https://txwhy.vercel.app/api/mcp",
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add sundram07-txwhy --url 'https://txwhy.vercel.app/api/mcp' --transport streamable-http
```

### Hermes

```yaml
mcp_servers:
  sundram07-txwhy:
    url: "https://txwhy.vercel.app/api/mcp"
```

### Netclaw

```json
{
  "McpServers": {
    "sundram07-txwhy": {
      "Transport": "http",
      "Url": "https://txwhy.vercel.app/api/mcp"
    }
  }
}
```

### Vellum

```bash
assistant mcp add sundram07-txwhy -t streamable-http -u 'https://txwhy.vercel.app/api/mcp'
```

### Other

```json
{
  "mcpServers": {
    "sundram07-txwhy": {
      "type": "http",
      "url": "https://txwhy.vercel.app/api/mcp"
    }
  }
}
```

The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.

## Changelog

Every change recorded for this component, newest first. Days that predate change tracking, or that we cannot explain, say so: "we were watching and nothing happened" and "we were not watching" are different claims.

### 2026-10-22 (score 74, +1)

No change was recorded against any check on this day. Stability & Change Management went from 40 to 43. That category is still filling its 30-day observation window: 12 days of observed history at the previous scan, 13 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-20 (score 73, +1)

No change was recorded against any check on this day. Stability & Change Management went from 33 to 37. That category is still filling its 30-day observation window: 10 days of observed history at the previous scan, 11 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-17 (score 72, +1)

No change was recorded against any check on this day. Stability & Change Management went from 23 to 27. That category is still filling its 30-day observation window: 7 days of observed history at the previous scan, 8 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-15 (score 71, +1)

No change was recorded against any check on this day. Stability & Change Management went from 17 to 20. That category is still filling its 30-day observation window: 5 days of observed history at the previous scan, 6 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-13 (score 70, +1)

No change was recorded against any check on this day. Stability & Change Management went from 10 to 13. That category is still filling its 30-day observation window: 3 days of observed history at the previous scan, 4 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-12 (score 69, +1)

No change was recorded against any check on this day. Stability & Change Management went from 3 to 10. That category is still filling its 30-day observation window: 1 days of observed history at the previous scan, 3 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-10 (score 68, 0)

- [functional improvement] Stability: unverified → 0.03

### 2026-10-09 (score 68)

First indexed and scored.

## MCP tools (3)

### `repair_transaction` (~263 tokens)

Repair a Solana transaction

Give it a Solana transaction that failed, or one you are about to send. It finds the cause and returns a rebuilt UNSIGNED transaction that has been simulated against live mainnet state to prove it passes. Fixes expired blockhashes, compute-unit limits, priority fees, loaded-data limits, slippage on plain Jupiter swaps (fresh quote, same tolerance), and slippage on direct Pump.fun, PumpSwap, Raydium AMM v4, Meteora DBC and Meteora DAMM v2 swaps (only the limit moves, never more than 25% against the user). Handles legacy, v0 and version 1 (SIMD-0385) transactions and durable nonces. When the failure cannot be fixed by rebuilding (not enough funds, a private program's own error), it says so and explains why instead of returning something that would fail again. Pass exactly one of `transaction` or `signature`. Sign the returned transaction with your own key and send it within about 60 seconds.

Input parameters:

- `signature` (string): Signature (or explorer URL) of a transaction that already landed on mainnet and failed.
- `transaction` (string): Base64 serialized transaction, signed or unsigned. Use this before sending, or after a send failed.

### `diagnose_transaction` (~70 tokens)

Diagnose a failed Solana transaction

Explains why a transaction that landed on mainnet failed: the exact failing instruction in the call tree, the named error, its cause, and how to fix it. Read-only and fast. Use repair_transaction when you want a working transaction back.

Input parameters:

- `signature` (string, required): Transaction signature or explorer URL.

### `explain_error` (~108 tokens)

Explain a Solana program error code

Looks up what a custom program error code means for a given program, using 1,800+ named errors from major Solana programs plus the runtime's own errors. Use it when you only have a code such as 6001 or 0x1771 from a simulation or an RPC response.

Input parameters:

- `code` (required): Error code as a number, or a hex string like 0x1771.
- `programId` (string, required): Base58 address of the program that raised the error.

## Diagnostics

Captured diagnostic sections: TLS, DNSSEC, Authorisation, Transports. The full working is on the page: https://verifymcp.io/servers/sundram07-txwhy/api-mcp#diagnostics

## Score history

- 2026-10-22: 74
- 2026-10-21: 73
- 2026-10-20: 73
- 2026-10-19: 72
- 2026-10-18: 72
- 2026-10-17: 72
- 2026-10-16: 71
- 2026-10-15: 71
- 2026-10-14: 70
- 2026-10-13: 70
- 2026-10-12: 69
- 2026-10-10: 68
- 2026-10-09: 68

## Common questions

### What is the TxWhy MCP server?

TxWhy is an MCP server listed in the public MCP registry as io.github.SUNDRAM07/txwhy. Failed Solana transaction in, working transaction out. Exact cause, rebuilt tx, verifiable repair. This page covers its hosted endpoint (https://txwhy.vercel.app/api/mcp).

### Is the TxWhy MCP server safe to use?

TxWhy scores 74 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 TxWhy MCP server expose?

TxWhy exposes 3 tools: repair_transaction, diagnose_transaction, explain_error. Their descriptions and schemas cost roughly 441 tokens of context every time the server is loaded.

### Does the TxWhy MCP server require authentication?

No. We connected to TxWhy without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.

### Is the TxWhy MCP server still maintained?

TxWhy is still listed as active in the MCP registry. We last reached this channel on 22 October 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.

## Links

- Remote endpoint: https://txwhy.vercel.app/api/mcp
- Website: https://txwhy.vercel.app/
- Changelog RSS feed: https://verifymcp.io/servers/sundram07-txwhy/api-mcp.xml
- Changelog JSON feed: https://verifymcp.io/servers/sundram07-txwhy/api-mcp.json
- HTML version of this page: https://verifymcp.io/servers/sundram07-txwhy/api-mcp