# JsonMend (remote · jsonmend.mike-tusa.workers.dev)

Repair broken JSON from LLM output and validate it against a JSON Schema.

- Trust score: 68/100 (medium)
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-10-17

## Components

- remote · `jsonmend.mike-tusa.workers.dev`: 68/100 (this document), [markdown](https://verifymcp.io/servers/dev-workers-mike-tusa-jsonmend-jsonmend/jsonmend.md), [page](https://verifymcp.io/servers/dev-workers-mike-tusa-jsonmend-jsonmend/jsonmend)

## Channel facts

- Endpoint: `https://jsonmend.mike-tusa.workers.dev/mcp`
- Transports: `streamable-http`
- Auth: `none`
- Version: `0.1.3`

## 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 2026-10-17.

- **Endpoint Security**: 69/100
  - The endpoint's TLS certificate is valid, in date, and uses a strong key.
  - No authorisation is required to call this server. Every tool declares its destructiveHint and none is destructive, so open access doesn't expose one.
  - HTTPS enforcement could not be verified: the plaintext port answered with HTTP 405, which proves neither a plaintext path nor enforcement.
  - 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**: 63/100
  - AI-judged instruction clarity (excellent).
  - Context-footprint check failed: tool/resource definitions use about 975 tokens (~487/item across 2 items; 2 tools + 0 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 7/100
  - Stability observed for 2 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.
  - Structured output schemas are declared (100% of tools); any adoption earns full credit.
- **Tool Safety**: 100/100
  - No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.
  - We read all 2 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 JsonMend MCP server?

JsonMend is a hosted endpoint at https://jsonmend.mike-tusa.workers.dev/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 dev-workers-mike-tusa-jsonmend-jsonmend 'https://jsonmend.mike-tusa.workers.dev/mcp'
```

### Cursor

```json
{
  "mcpServers": {
    "dev-workers-mike-tusa-jsonmend-jsonmend": {
      "url": "https://jsonmend.mike-tusa.workers.dev/mcp"
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "dev-workers-mike-tusa-jsonmend-jsonmend": {
      "type": "http",
      "url": "https://jsonmend.mike-tusa.workers.dev/mcp"
    }
  }
}
```

### Codex

```toml
[mcp_servers.dev-workers-mike-tusa-jsonmend-jsonmend]
url = "https://jsonmend.mike-tusa.workers.dev/mcp"
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "dev-workers-mike-tusa-jsonmend-jsonmend": {
      "type": "remote",
      "url": "https://jsonmend.mike-tusa.workers.dev/mcp",
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add dev-workers-mike-tusa-jsonmend-jsonmend --url 'https://jsonmend.mike-tusa.workers.dev/mcp' --transport streamable-http
```

### Hermes

```yaml
mcp_servers:
  dev-workers-mike-tusa-jsonmend-jsonmend:
    url: "https://jsonmend.mike-tusa.workers.dev/mcp"
```

### Netclaw

```json
{
  "McpServers": {
    "dev-workers-mike-tusa-jsonmend-jsonmend": {
      "Transport": "http",
      "Url": "https://jsonmend.mike-tusa.workers.dev/mcp"
    }
  }
}
```

### Vellum

```bash
assistant mcp add dev-workers-mike-tusa-jsonmend-jsonmend -t streamable-http -u 'https://jsonmend.mike-tusa.workers.dev/mcp'
```

### Other

```json
{
  "mcpServers": {
    "dev-workers-mike-tusa-jsonmend-jsonmend": {
      "type": "http",
      "url": "https://jsonmend.mike-tusa.workers.dev/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.

### 2026-10-17 (score 68, +1)

- [functional] Server version: 0.1.3 → 0.1.4

### 2026-10-16 (score 67, 0)

- [functional improvement] Stability: unverified → 0.03

### 2026-10-15 (score 67)

First indexed and scored.

## MCP tools (2)

### `repair_json` (~386 tokens)

Repair broken JSON (LLM output) and list the fixes

Turn broken or messy JSON text into valid JSON. Strips Markdown code fences and prose before/after the JSON, removes comments and trailing commas, converts single/curly quotes, quotes unquoted keys, maps Python None/True/False, inserts missing commas, closes truncated strings/arrays/objects, and wraps NDJSON / several concatenated objects into one array. Returns the parsed value (json), the repaired text, and the list of fixes applied; valid input passes through unchanged with no fixes. Optional schema (+ coerce) also validates the result. Fails with isError (code unrepairable / no_json_found) when nothing JSON-like can be recovered. Pure computation: read-only, no network access, inputs not stored. Same engine and limits as POST /api/v1/repair.

Input parameters:

- `coerce` (boolean): Convert values toward the schema's declared types before validating: "42" → 42, "true" → true, "null" → null, 5 → "5", x → [x]. Each change is listed in coercions.
- `draft` (string): JSON Schema draft. Default: from the schema's $schema, else 2020-12.
- `format` (string): Layout of the returned text: compact (default), pretty (2-space indent), or preserve (jsonrepair's output, keeps original spacing and long-number digits).
- `input` (string, required): The raw (possibly broken) JSON text, e.g. an LLM reply with code fences and prose around the JSON. Max 102,400 bytes (UTF-8).
- `schema` (object): A JSON Schema (draft 2020-12 by default; 2019-09, 7 and 4 also supported). Only local $refs (#/...) resolve; remote $refs are an error. Max 32 KB.

Output parameters:

- `changed` (boolean): false when the input was already valid JSON
- `fixes` (array)
- `format` (string)
- `inputBytes` (integer)
- `inputWasValid` (boolean)
- `json`: The repaired JSON value (coerced if coerce was used)
- `ok` (boolean)
- `outputBytes` (integer)
- `plan` (string)
- `schema` (object)
- `values` (integer): Number of top-level JSON values found (more than 1 = wrapped in an array)
- `version` (string)
- `warnings` (array)

### `validate_json` (~347 tokens)

Validate JSON against a JSON Schema (repairs broken input first)

Check JSON against a JSON Schema and get every error with its JSON Pointer path. Send the JSON either as text ("input"; broken text is repaired first, and the fixes are listed) or as an already-parsed value ("data"). Optional coerce converts "42" → 42, "true" → true, etc. toward the schema's types before validating and lists each change. A schema mismatch is a normal result (valid: false), not an error. Drafts 2020-12 (default), 2019-09, 7, 4; only local $refs. Pure computation: read-only, no network access, inputs not stored. Same engine and limits as POST /api/v1/validate.

Input parameters:

- `coerce` (boolean): Convert values toward the schema's declared types before validating: "42" → 42, "true" → true, "null" → null, 5 → "5", x → [x]. Each change is listed in coercions.
- `data`: An already-parsed JSON value to validate. Send this or "input", not both.
- `draft` (string): JSON Schema draft. Default: from the schema's $schema, else 2020-12.
- `input` (string): JSON text to validate (repaired first if broken). Send this or "data", not both. Max 102,400 bytes.
- `schema` (object, required): A JSON Schema (draft 2020-12 by default; 2019-09, 7 and 4 also supported). Only local $refs (#/...) resolve; remote $refs are an error. Max 32 KB.

Output parameters:

- `coerced` (boolean)
- `coercions` (array)
- `draft` (string)
- `errorCount` (integer): Total errors (at most 50 are listed); a lower bound when errorsTruncated is true
- `errors` (array)
- `errorsTruncated` (boolean): true when the validator produced more than 5,000 raw errors and only the first 5,000 were examined
- `fixes` (array)
- `json`: The validated value (after repair and coercion)
- `ok` (boolean)
- `plan` (string)
- `repaired` (boolean): true when "input" needed repair before validation
- `valid` (boolean)
- `version` (string)
- `warnings` (array)

## Diagnostics

Captured diagnostic sections: TLS, DNSSEC, Authorisation, Transports. The full working is on the page: https://verifymcp.io/servers/dev-workers-mike-tusa-jsonmend-jsonmend/jsonmend#diagnostics

## Score history

- 2026-10-17: 68
- 2026-10-16: 67
- 2026-10-15: 67

## Common questions

### What is the JsonMend MCP server?

JsonMend is an MCP server listed in the public MCP registry as dev.workers.mike-tusa.jsonmend/jsonmend. Repair broken JSON from LLM output and validate it against a JSON Schema. This page covers its hosted endpoint (https://jsonmend.mike-tusa.workers.dev/mcp).

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

JsonMend scores 68 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 JsonMend MCP server expose?

JsonMend exposes 2 tools: repair_json, validate_json. Their descriptions and schemas cost roughly 733 tokens of context every time the server is loaded.

### Does the JsonMend MCP server require authentication?

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

### Is the JsonMend MCP server still maintained?

JsonMend is still listed as active in the MCP registry. We last reached this channel on 17 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://jsonmend.mike-tusa.workers.dev/mcp
- Website: https://jsonmend.mike-tusa.workers.dev/
- Changelog RSS feed: https://verifymcp.io/servers/dev-workers-mike-tusa-jsonmend-jsonmend/jsonmend.xml
- Changelog JSON feed: https://verifymcp.io/servers/dev-workers-mike-tusa-jsonmend-jsonmend/jsonmend.json
- HTML version of this page: https://verifymcp.io/servers/dev-workers-mike-tusa-jsonmend-jsonmend/jsonmend