# io.github.sebastienrousseau/noyalib-mcp (oci · ghcr.io/sebastienrousseau/noyalib-mcp)

MCP server for lossless YAML 1.2 parsing, formatting, and validation (pure Rust).

- Trust score: 68/100 (medium)
- Change this week: +3
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-11-05

## Components

- oci · `ghcr.io/sebastienrousseau/noyalib-mcp`: 68/100 (this document), [markdown](https://verifymcp.io/servers/sebastienrousseau-noyalib-mcp/ghcr-io-sebastienrousseau-noyalib-mcp.md), [page](https://verifymcp.io/servers/sebastienrousseau-noyalib-mcp/ghcr-io-sebastienrousseau-noyalib-mcp)

## Channel facts

- Registry: `oci`
- Package: `ghcr.io/sebastienrousseau/noyalib-mcp`
- Version: `0.0.58`
- Transport: `stdio`

## Trust breakdown

How this component scores in each security and reliability category. Every signal is checked automatically from public evidence about the published package, including repeated runs of it in an isolated sandbox, 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 2026-11-05.

- **Supply Chain Security**: 0/100
  - No malware scan is available for this kind of package: the supply-chain vendors we use do not cover it. This is a permanent gap in our coverage, not a finding about the package.
  - Known CVEs could not be checked: this artifact ships no SBOM or dependency manifest, so there is no dependency list to read.
  - Install-script risk not yet assessed.
  - Dependency health could not be checked: this artifact ships no SBOM or dependency manifest, so there is no dependency list to read.
- **Provenance & Transparency**: 100/100
  - Source repository is publicly reachable at the declared URL.
  - Cryptographically verified build provenance (signed, bound to sebastienrousseau/noyalib-mcp).
  - Clear OSI-approved license (MIT OR Apache-2.0).
  - Actively maintained (last published 19 days ago).
  - Publishes a security disclosure policy (SECURITY.md).
- **Schema Quality & AI Usability**: 87/100
  - 100% of prompts and resources have a non-trivial description (not blank, and not just the item's name).
  - AI-judged instruction clarity (excellent).
  - Context-footprint check failed: tool/resource definitions use about 944 tokens (~118/item across 8 items; 6 tools + 2 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 100/100
  - No destabilizing schema changes in the last 30 days.
- **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 6 captured tool definition(s), and no name or description among them implies an irreversible operation.
  - An AI judge read all 8 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).

**Unverified: 1 category.** A category scored 0 because we could not verify it: a data source with nothing on this package, evidence we could not reach, or a check we could not run. We only credit what we can confirm.

## Install

### How do I install the io.github.sebastienrousseau/noyalib-mcp server?

io.github.sebastienrousseau/noyalib-mcp runs locally as a container image, launched with docker run --rm -i ghcr.io/sebastienrousseau/noyalib-mcp:0.0.58. Ready-made configuration for Claude, Cursor, VS Code, Codex and 3 more is on this page, copied from each client's own documentation.

### Claude

```bash
claude mcp add sebastienrousseau-noyalib-mcp -- docker run --rm -i ghcr.io/sebastienrousseau/noyalib-mcp:0.0.58
```

### Cursor

```json
{
  "mcpServers": {
    "sebastienrousseau-noyalib-mcp": {
      "command": "docker",
      "args": [
        "run",
        "--rm",
        "-i",
        "ghcr.io/sebastienrousseau/noyalib-mcp:0.0.58"
      ]
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "sebastienrousseau-noyalib-mcp": {
      "command": "docker",
      "args": [
        "run",
        "--rm",
        "-i",
        "ghcr.io/sebastienrousseau/noyalib-mcp:0.0.58"
      ]
    }
  }
}
```

### Codex

```bash
codex mcp add sebastienrousseau-noyalib-mcp -- docker run --rm -i ghcr.io/sebastienrousseau/noyalib-mcp:0.0.58
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "sebastienrousseau-noyalib-mcp": {
      "type": "local",
      "command": [
        "docker",
        "run",
        "--rm",
        "-i",
        "ghcr.io/sebastienrousseau/noyalib-mcp:0.0.58"
      ],
      "enabled": true
    }
  }
}
```

### Hermes

```yaml
mcp_servers:
  sebastienrousseau-noyalib-mcp:
    command: "docker"
    args: ["run", "--rm", "-i", "ghcr.io/sebastienrousseau/noyalib-mcp:0.0.58"]
```

### Netclaw

```json
{
  "McpServers": {
    "sebastienrousseau-noyalib-mcp": {
      "Transport": "stdio",
      "Command": "docker",
      "Arguments": [
        "run",
        "--rm",
        "-i",
        "ghcr.io/sebastienrousseau/noyalib-mcp:0.0.58"
      ]
    }
  }
}
```

### Other

```json
{
  "mcpServers": {
    "sebastienrousseau-noyalib-mcp": {
      "command": "docker",
      "args": [
        "run",
        "--rm",
        "-i",
        "ghcr.io/sebastienrousseau/noyalib-mcp:0.0.58"
      ]
    }
  }
}
```

## 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.

### 2026-11-04 (score 68, +1)

- [functional improvement] Security disclosure: unverified → pass

### 2026-11-03 (score 67, 0)

- [security] Stability: 0.97 → pass
- [functional regression] Security disclosure: pass → unverified

### 2026-11-01 (score 67, +1)

No change was recorded against any check on this day. Stability & Change Management went from 90 to 93. That category is still filling its 30-day observation window: 27 days of observed history at the previous scan, 28 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-30 (score 66, +1)

No change was recorded against any check on this day. Stability & Change Management went from 83 to 87. That category is still filling its 30-day observation window: 25 days of observed history at the previous scan, 26 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-28 (score 65, +1)

No change was recorded against any check on this day. Stability & Change Management went from 77 to 80. That category is still filling its 30-day observation window: 23 days of observed history at the previous scan, 24 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-26 (score 64, +1)

No change was recorded against any check on this day. Stability & Change Management went from 70 to 73. That category is still filling its 30-day observation window: 21 days of observed history at the previous scan, 22 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-24 (score 63, +1)

No change was recorded against any check on this day. Stability & Change Management went from 63 to 67. That category is still filling its 30-day observation window: 19 days of observed history at the previous scan, 20 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-21 (score 62, +1)

No change was recorded against any check on this day. Stability & Change Management went from 53 to 57. That category is still filling its 30-day observation window: 16 days of observed history at the previous scan, 17 at this one. The score rises as the window fills, whether or not the server changes.

## MCP tools (6)

### `noyalib_edit` (~121 tokens)

Edit a value in YAML text, losslessly (stateless)

Set the value at a dotted/indexed path in the YAML text given in the request and return the whole edited text. Only the touched span changes; every comment, blank line and quote style elsewhere is preserved byte-for-byte. Nothing on disk is touched: the caller decides where the result goes.

Input parameters:

- `path` (string, required): Dotted/indexed path, e.g. `server.port` or `items[0].name`.
- `value` (string, required): Replacement value as a YAML fragment.
- `yaml` (string, required): The YAML text to edit.

Output parameters:

- `yaml` (string): The whole YAML text with the one value replaced.

### `noyalib_get` (~116 tokens)

Read a YAML value (lossless)

Read the YAML value at a dotted/indexed path in the given file and return the source slice exactly — no re-quoting, no canonicalisation, comments and formatting preserved. Use this to inspect a value before changing it; use `noyalib_set` to write a value back losslessly.

Input parameters:

- `file` (string, required): Path to the YAML file on disk.
- `path` (string, required): Dotted/indexed path into the YAML, e.g. `server.host` or `items[0].name`.

Output parameters:

- `value` (string): The source slice at the path, exactly as written: no re-quoting, no canonicalisation. Empty for a key with no value.

### `noyalib_parse` (~105 tokens)

Parse YAML text into JSON (stateless)

Parse the YAML text given in the request and return its JSON data model (custom tags stripped, the projection the official YAML test suite expects). Multi-document streams return a JSON array with one element per document. Refuses hostile input (nesting, alias expansion, size) and duplicate keys under the strict YAML 1.2 profile, the same rules as the library. Nothing is read from or written to disk.

Input parameters:

- `yaml` (string, required): The YAML text to parse.

Output parameters:

- `documents` (array): One JSON value per document of the stream, custom tags stripped. A single-document text gives one element.

### `noyalib_set` (~173 tokens)

Write a YAML value (lossless)

Set the YAML value at a dotted/indexed path in the given file, rewriting only the touched span so every comment, blank line, and sibling entry is preserved byte-for-byte (written atomically). Use this for Renovate-style version bumps and config patches; use `noyalib_get` first when you need to read the current value. On a parse error the document is left unchanged.

Input parameters:

- `file` (string, required): Path to the YAML file on disk.
- `path` (string, required): Dotted/indexed path into the YAML.
- `value` (string, required): Replacement value as a YAML fragment (e.g. `0.0.2`, `"hello"`, `[1, 2, 3]`). Must parse in the target position; the document is left unchanged on parse error.

Output parameters:

- `file` (string): The file that was rewritten.
- `path` (string): The path that was set.
- `value` (string): The YAML fragment now at that path.

### `noyalib_set_multidoc` (~195 tokens)

Write a YAML value in one document of a multi-doc stream (lossless)

Set the YAML value at a dotted/indexed path within a single document of a multi-document (`---`-separated) YAML stream, selected by zero-based document index. Only the touched span of that one document is rewritten; every other document, comment, blank line and separator is preserved byte-for-byte (written atomically). Use `noyalib_set` for a single-document file. On a parse error or out-of-range index the file is left unchanged.

Input parameters:

- `doc_index` (integer, required): Zero-based index of the document within the `---`-separated stream to modify.
- `file` (string, required): Path to the multi-document YAML file on disk.
- `path` (string, required): Dotted/indexed path into the selected document.
- `value` (string, required): Replacement value as a YAML fragment. Must parse in the target position; the file is left unchanged on parse error.

Output parameters:

- `doc_index` (integer): The zero-based index of the document that changed.
- `file` (string): The file that was rewritten.
- `path` (string): The path that was set, within that document.
- `value` (string): The YAML fragment now at that path.

### `noyalib_validate` (~107 tokens)

Validate YAML text, optionally against a JSON Schema (stateless)

Check that the YAML text parses under the library's limits, and when a JSON Schema (as JSON text) is given, that the document satisfies it. Returns `valid` with an empty list, or the parse error with its line and column, or every schema violation with its RFC 6901 path. Nothing on disk is touched.

Input parameters:

- `schema` (string|null): A JSON Schema, as JSON text (optional).
- `yaml` (string, required): The YAML text to validate.

Output parameters:

- `column` (integer|null): The column of the parse error, when there is one.
- `error` (string|null): The parse error, when the text does not parse.
- `line` (integer|null): The line of the parse error, when there is one.
- `valid` (boolean): Whether the text parses and, when a schema was given, satisfies it.
- `violations` (array): Every schema violation; empty when the document is valid or no schema was given.

## Diagnostics

Captured diagnostic sections: Provenance. The full working is on the page: https://verifymcp.io/servers/sebastienrousseau-noyalib-mcp/ghcr-io-sebastienrousseau-noyalib-mcp#diagnostics

## Score history

- 2026-11-05: 68
- 2026-11-04: 68
- 2026-11-03: 67
- 2026-11-02: 67
- 2026-11-01: 67
- 2026-10-31: 66
- 2026-10-30: 66
- 2026-10-29: 65
- 2026-10-28: 65
- 2026-10-27: 64
- 2026-10-26: 64
- 2026-10-25: 63
- 2026-10-24: 63
- 2026-10-23: 62
- 2026-10-22: 62
- 2026-10-21: 62
- 2026-10-20: 61
- 2026-10-19: 61
- 2026-10-18: 60
- 2026-10-17: 60
- 2026-10-16: 59
- 2026-10-15: 59
- 2026-10-14: 58
- 2026-10-13: 20
- 2026-10-12: 20
- 2026-10-05: 54
- 2026-10-04: 54

## Common questions

### What is the io.github.sebastienrousseau/noyalib-mcp server?

io.github.sebastienrousseau/noyalib-mcp is listed in the public MCP registry as io.github.sebastienrousseau/noyalib-mcp. MCP server for lossless YAML 1.2 parsing, formatting, and validation (pure Rust). This page covers its container image (ghcr.io/sebastienrousseau/noyalib-mcp).

### Is the io.github.sebastienrousseau/noyalib-mcp server safe to use?

io.github.sebastienrousseau/noyalib-mcp scores 68 out of 100 on VerifyMCP. Its build provenance is signed and verified. 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 io.github.sebastienrousseau/noyalib-mcp server expose?

io.github.sebastienrousseau/noyalib-mcp exposes 6 tools: noyalib_edit, noyalib_get, noyalib_parse, noyalib_set, noyalib_set_multidoc, noyalib_validate. Their descriptions and schemas cost roughly 817 tokens of context every time the server is loaded.

### Is the io.github.sebastienrousseau/noyalib-mcp server still maintained?

io.github.sebastienrousseau/noyalib-mcp is still listed as active in the MCP registry. We last reached this channel on 5 November 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.

### What licence is the io.github.sebastienrousseau/noyalib-mcp server under?

io.github.sebastienrousseau/noyalib-mcp declares the MIT OR Apache-2.0 licence, which is OSI-approved. That covers the source only, and says nothing about the cost of any service it calls.

## Links

- GitHub Container Registry: https://ghcr.io/sebastienrousseau/noyalib-mcp
- Repository: https://github.com/sebastienrousseau/noyalib-mcp
- Changelog RSS feed: https://verifymcp.io/servers/sebastienrousseau-noyalib-mcp/ghcr-io-sebastienrousseau-noyalib-mcp.xml
- Changelog JSON feed: https://verifymcp.io/servers/sebastienrousseau-noyalib-mcp/ghcr-io-sebastienrousseau-noyalib-mcp.json
- HTML version of this page: https://verifymcp.io/servers/sebastienrousseau-noyalib-mcp/ghcr-io-sebastienrousseau-noyalib-mcp