Consume results programmatically

A gate that only passes or fails is the floor. Once manni meta is running, the same data behind the pass/fail decision can feed other tools. That means dashboards, PR bots, content catalogs, and custom checks, without re-parsing documents yourself.

manni meta exposes its results three ways, each suited to a different integration style:

• --format json: a single structured object per run, for pipelines that shell out and parse stdout.
• The get command: pull specific metadata field values out of files, for scripts that need a few values rather than a full validation report.
• The TypeScript API: call manni meta’s command cores directly from Node.js, for tools built on top of it.

JSON output

–format json

manni meta validate --format json prints one JSON object to stdout describing the whole run. It is the path for any tool that runs manni meta as a subprocess and reads its output.

npx -y @hawkeyexl/manni meta validate "docs/**/*.md" --format json

The object has a summary and a results array:

{
  "summary": {
    "files": 1,
    "passed": 0,
    "failed": 1,
    "errors": 1
  },
  "results": [
    {
      "file": "bad-timestamp.md",
      "format": "markdown",
      "ok": false,
      "schemas": ["google:okf:0.1"],
      "errors": [
        {
          "schema": "google:okf:0.1",
          "instancePath": "/timestamp",
          "message": "must match format \"date-time\"",
          "keyword": "format",
          "subject": "date-time",
          "line": 4
        }
      ]
    }
  ]
}

The fields:

• summary: run-wide counts: files checked, passed, failed, and the total errors across all files.
• results: one object per file: file (the path as manni meta saw it), format (the extractor that read it), ok, schemas (the resolved schema set), and errors.
• Each error carries schema, the schema id that produced it, and instancePath, a JSON Pointer to the field, or "" for the document root. It also carries message, keyword and subject. Finally line, 1-based, when manni meta can locate it, and col, 1-based, when the format can supply one.

Key on keyword, not on message

message is prose manni meta gets from Ajv, and an Ajv release can reword it. keyword is stable, and so is subject. keyword is the JSON Schema keyword that failed, such as required, format, pattern or type. subject is the identifier within it: the missing property, the additional property, the format name, the expected type. A script that counts “how many pages are missing owner” should match keyword === "required" && subject === "owner" rather than parse English.

subject is omitted for keywords whose parameter is a schema-authored value rather than an identifier, such as pattern’s regex or minLength’s number. manni meta’s own errors use keyword too: parse when a metadata block could not be read, schema when a schema set could not be resolved. Both keep schema: "(parse)".

line and col are both optional

line appears only when manni meta can map an error back to a source position, so parse it as optional. col is optional in a second way as well. Only the html and xml extractors resolve a column today. Even there it is omitted for a required violation, which reports the parent object and names the missing property. There is no column for something absent. Frontmatter formats (Markdown, MDX, AsciiDoc, reStructuredText) give a line and no column at all. Check for each field rather than assuming it exists.

The output is plain (never colorized) and goes to stdout, so it pipes cleanly into jq. List the files that failed:

npx -y @hawkeyexl/manni meta validate "docs/**/*.md" --format json \
  | jq -r '.results[] | select(.ok == false) | .file'

Flatten every error into a file:line message line for a log:

npx -y @hawkeyexl/manni meta validate "docs/**/*.md" --format json \
  | jq -r '.results[] | .file as $f
           | .errors[] | "\($f):\(.line // "?")  \(.message)"'

Read just the summary counts:

npx -y @hawkeyexl/manni meta validate "docs/**/*.md" --format json | jq '.summary'

Preserve the exit code through a pipe

Piping into jq replaces manni meta’s exit code with jq’s. You may need both the parsed output and the gate to fail on validation errors. Then write the report to a file with tee first, as manni meta validate ... --format json | tee report.json. Then run jq over report.json in a later step. See the CI recipes for capturing JSON as a build artifact.

get command

The get command

When a script needs metadata values rather than a validation verdict (say, to build an index of every page’s title and type), use manni meta get. It reads the named fields from each file and prints them. It shares validate’s input handling: positional paths, directories, globs, - for stdin with --as, the collections: from config as the fallback, and --collection <name> to narrow to one of them.

Pass the fields as a single comma-separated argument, then the targets:

npx -y @hawkeyexl/manni meta get title,tags docs/intro.md

For scripting, add --format json to get a structured array, one object per file:

npx -y @hawkeyexl/manni meta get title,tags "docs/**/*.md" --format json

[
  {
    "file": "docs/intro.md",
    "present": true,
    "values": {
      "title": "Introduction",
      "tags": ["onboarding", "guide"]
    }
  }
]

Each object reports:

• file: the file path.
• present: whether the file had a metadata block at all (false for a document with no frontmatter).
• values: the requested fields and their values.

Unset fields are omitted from JSON, not null

A requested field that the file does not define is left unset internally, and JSON.stringify drops unset values. So a field that is absent in the source does not appear as "field": null in the JSON; its key is omitted from values entirely. When you read the output, treat a missing key as “not present” rather than expecting an explicit null. In the pretty format the same case prints as field=(unset).

Reach into nested metadata

When frontmatter nests objects or arrays, a field reference can address the inner value instead of pulling the whole parent. Use dot-notation for the common case, or a JSON Pointer (any reference beginning with /) for keys that contain a literal .:

# frontmatter: author: { name: Jane }, tags: [intro, setup]
npx -y @hawkeyexl/manni meta get author.name,tags.0 docs/intro.md   # dot-notation
npx -y @hawkeyexl/manni meta get '/author/name' docs/intro.md       # JSON Pointer

The JSON Pointer form is the same path validate prints in an error location, so a pointer copied from a validation failure works verbatim. Requesting the parent key (author) still returns the whole nested object. See the get field reference for the full syntax.

Quote a leading-slash pointer ('/author/name') so Git Bash/MSYS2 on Windows does not rewrite it as a filesystem path. Other shells (PowerShell, cmd, POSIX) are unaffected, but quoting is harmless everywhere.

Extract one field across a tree into a shell list with jq:

npx -y @hawkeyexl/manni meta get type "docs/**/*.md" --format json \
  | jq -r '.[] | "\(.file)\t\(.values.type // "(none)")"'

get supports pretty and json only

manni meta get accepts --format pretty (the default) and --format json. It does not accept --format github, sarif, or junit: get reports values, not findings. github is available on validate and fill; sarif and junit are validate-only. Passing an unsupported format is a usage error and exits 2.

Add -q or --quiet to drop the files where every requested field is unset. A file with any of them set still prints, (unset) included.

TypeScript API

The TypeScript API

Some tools are built on top of manni meta. Think of a custom reporter, a bespoke gate, or a script that validates and then acts on the results. For those, call the command cores directly instead of shelling out. manni meta ships a programmatic entry point that exports the same cores the CLI is built on. You get structured results without spawning a process or parsing stdout.

The most common call is runValidate, which runs the full validation pipeline and returns the same { results, summary } structure that backs --format json:

import { runValidate } from "@hawkeyexl/manni";

const { results, summary } = await runValidate({
  inputs: ["docs/**/*.md"],
  cliSchemas: ["google:okf:0.1"],
});

console.log(`${summary.passed}/${summary.files} files passed`);

for (const result of results) {
  if (result.ok) continue;
  for (const err of result.errors) {
    console.log(`${result.file}: ${err.instancePath} ${err.message}`);
  }
}

runValidate accepts a ValidateOptions object. The fields mirror the CLI:

• inputs: files, directories, or globs to validate. When empty, manni meta falls back to the collections: declared in the config, exactly as the CLI does.
• collections: collection names to run over, the programmatic equivalent of a repeated --collection. Like the flag, it cannot be combined with a non-empty inputs.
• cliSchemas: schema references that override $schema and config (the programmatic equivalent of --schema).
• exts, exclude, as, configPath: directory-walk extensions, exclude globs, a forced extractor name, and a config-file path.
• stdinContent: content for a - (stdin) input, supplied directly rather than read from the process.

It resolves to a ValidateRun of {{ results, summary }}, using the ValidationResult and RunSummary shapes that the JSON format serializes.

Alongside runValidate, the entry point exports the other command cores, the schema-resolution and config helpers, the reporters, the extractors, and every result type they use. The TypeScript API reference lists all of them.

Operational failures throw DocmetaError

The cores throw a DocmetaError for operational problems: no inputs and no config, an unknown --as format, an unreadable config, an unresolvable schema. This is the same condition the CLI maps to exit 2. A validation failure, by contrast, is not thrown: it comes back as a result with ok: false. Wrap calls in try/catch to handle the operational case, and inspect summary.failed (or each result.ok) for the validation case.

ESM, Node 24+

manni meta is an ES module targeting Node.js 24 or newer. Import it from ESM (or a .mts / .ts file compiled to ESM); there is no CommonJS require entry.

Which one to reach for

1. A subprocess in any language? Use --format json and parse stdout. It is language-agnostic and the most stable surface.

2. A shell script that needs a few field values? Use get; it is purpose-built for pulling named fields without a full validation report.

3. A Node.js or TypeScript tool? Call the API. You skip process spawning and stdout parsing, and you get typed results.

Next steps

Exit codes & PR annotationsThe full json, sarif, and junit shapes, the 0/1/2 exit contract, and the github annotation format.

Govern a shared schema across reposPoint many repos at one central, versioned schema and feed the results here.

CI recipesCapture JSON as a build artifact on GitLab CI, Jenkins, and pre-commit.