# Crossref DOI Metadata QA (`nexgenwatch/crossref-doi-metadata-qa`) Actor

A per-DOI QA verdict from official Crossref metadata — each DOI returns valid, not\_found, or metadata\_incomplete with every missing required field named. Billed per definitive verdict.

- **URL**: https://apify.com/nexgenwatch/crossref-doi-metadata-qa.md
- **Developed by:** [NexGen Watch](https://apify.com/nexgenwatch) (community)
- **Categories:** Developer tools
- **Stats:** 2 total users, 1 monthly users, 100.0% runs succeeded, 0 bookmarks
- **User rating**: No ratings yet

## Pricing

from $33.50 / 1,000 metadata qa checks

This Actor is paid per event. You are not charged for the Apify platform usage, but only a fixed price for specific events.
Since this Actor supports Apify Store discounts, the price gets lower the higher subscription plan you have.

Learn more: https://docs.apify.com/actors/running/actors-in-store.md#pay-per-event

## What's an Apify Actor?

Actors are web data automations that power AI and operations. They run on the Apify platform to scrape websites, process data, connect APIs, and automate workflows.
In Batch mode, an Actor accepts a well-defined JSON input, performs an action which can take anything from a few seconds to a few hours,
and optionally produces a well-defined JSON output, datasets with results, or files in key-value store.
In Standby mode, an Actor provides a web server which can be used as a website, API, or an MCP server.
Actors are written with capital "A".

## How to integrate an Actor?

If asked about integration, you help developers integrate Actors into their projects.
You adapt to their stack and deliver integrations that are safe, well-documented, and production-ready.
The best way to integrate Actors is as follows.

- **AI agents and MCP clients** — the [Apify MCP server](https://docs.apify.com/integrations/mcp.md) at `https://mcp.apify.com` (remote, streamable HTTP, OAuth on first use).
- **Agentic workflows and local Actor development** — [Agent Skills](https://apify.com/.well-known/agent-skills/index.json) with the [Apify CLI](https://docs.apify.com/cli/docs.md): `npm install -g apify-cli`, then `apify login`.
- **JavaScript/TypeScript projects** — the official [JS/TS client](https://docs.apify.com/api/client/js/docs.md): `npm install apify-client`.
- **Python projects** — the official [Python client](https://docs.apify.com/api/client/python/docs.md): `pip install apify-client`.
- **Any other language** — the [REST API](https://docs.apify.com/api/v2.md).

For usage examples, see the [API](#api) section below.

For more details, see Apify documentation as [Markdown index](https://docs.apify.com/llms.txt) and [Markdown full-text](https://docs.apify.com/llms-full.txt).

# README

## Crossref DOI Metadata QA

A per-DOI **verdict** product — not a metadata dump. Submit DOIs, get one deterministic QA verdict each: `valid`, `not_found`, or `metadata_incomplete` (with every missing required field **named**). Billed **per definitive verdict**.

### How it behaves

Each DOI is canonicalized (`https://doi.org/…`, `doi:` prefixes stripped) and syntax-validated. A syntactically valid DOI is looked up once against the official **keyless Crossref REST API** (contact-bearing UA, polite rate limit, bounded retries). The buyer-selected **required-field profile** (`requiredFields`, default: title, author, issued, type, container-title, publisher) is tested against the record:

- all present → **valid**;
- some missing → **metadata\_incomplete**, with the missing fields named;
- DOI not registered in Crossref → **not\_found**.

Input order is preserved. The verdict record carries **minimal identifying context only** (title, type, publisher) — the payload is the verdict, never a metadata dump.

### Billing

| Event | FREE | BRONZE | SILVER | GOLD+ |
|---|---|---|---|---|
| `apify-actor-start` (one-time actor start) | $0.02 | $0.02 | $0.02 | $0.02 |
| `metadata-qa-check` (per definitive verdict) | $0.05 | $0.045 | $0.04 | $0.0335 |

A definitive verdict (valid / not\_found / metadata\_incomplete) is charged once. **Locally-invalid DOI syntax and Crossref outages are emitted but never charged.** Start fee $0.02.

### Differentiation

- vs our `crossref-citation-mcp`: this is **batch QA verdicts** for metadata operations, not per-call retrieval for agents.
- vs the store comparators: **deterministic, order-preserving verdicts with named missing fields**, not search exports.

### Source

`https://api.crossref.org/works`

# Actor input Schema

## `dois` (type: `array`):

DOIs to QA against Crossref (e.g. 10.1038/nphys1170; https://doi.org/... and doi: prefixes are canonicalized). One verdict per DOI, input order preserved. A definitive verdict (valid / not\_found / metadata\_incomplete) bills; locally-invalid DOI syntax and Crossref outages never bill.

## `requiredFields` (type: `array`):

The buyer-selected fields that must be present for a `valid` verdict. Any missing field is NAMED and the verdict becomes metadata\_incomplete. Default: title, author, issued, type, container-title, publisher. Options include: title, author, issued/published, type, container-title, publisher, doi, abstract, issn, references, license, funder, url.

## Actor input object example

```json
{
  "dois": [
    "10.1038/nphys1170",
    "https://doi.org/10.1145/3292500.3330701",
    "10.9999/nonexistent-zzz-000",
    "not-a-doi"
  ],
  "requiredFields": [
    "title",
    "author",
    "issued",
    "type",
    "container-title",
    "publisher"
  ]
}
```

# Actor output Schema

## `results` (type: `string`):

No description

# API

You can run this Actor programmatically using our API. Below are code examples in JavaScript, Python, and CLI, as well as the OpenAPI specification and MCP server setup.

## JavaScript example

```javascript
import { ApifyClient } from 'apify-client';

// Initialize the ApifyClient with your Apify API token
// Replace the '<YOUR_API_TOKEN>' with your token
const client = new ApifyClient({
    token: '<YOUR_API_TOKEN>',
});

// Prepare Actor input
const input = {
    "dois": [
        "10.1038/nphys1170",
        "https://doi.org/10.1145/3292500.3330701",
        "10.9999/nonexistent-zzz-000",
        "not-a-doi"
    ],
    "requiredFields": [
        "title",
        "author",
        "issued",
        "type",
        "container-title",
        "publisher"
    ]
};

// Run the Actor and wait for it to finish
const run = await client.actor("nexgenwatch/crossref-doi-metadata-qa").call(input);

// Fetch and print Actor results from the run's dataset (if any)
console.log('Results from dataset');
console.log(`💾 Check your data here: https://console.apify.com/storage/datasets/${run.defaultDatasetId}`);
const { items } = await client.dataset(run.defaultDatasetId).listItems();
items.forEach((item) => {
    console.dir(item);
});

// 📚 Want to learn more 📖? Go to → https://docs.apify.com/api/client/js/docs

```

## Python example

```python
from apify_client import ApifyClient

# Initialize the ApifyClient with your Apify API token
# Replace '<YOUR_API_TOKEN>' with your token.
client = ApifyClient("<YOUR_API_TOKEN>")

# Prepare the Actor input
run_input = {
    "dois": [
        "10.1038/nphys1170",
        "https://doi.org/10.1145/3292500.3330701",
        "10.9999/nonexistent-zzz-000",
        "not-a-doi",
    ],
    "requiredFields": [
        "title",
        "author",
        "issued",
        "type",
        "container-title",
        "publisher",
    ],
}

# Run the Actor and wait for it to finish
run = client.actor("nexgenwatch/crossref-doi-metadata-qa").call(run_input=run_input)

# Fetch and print Actor results from the run's dataset (if there are any)
print(f"💾 Check your data here: https://console.apify.com/storage/datasets/{run.default_dataset_id}")
for item in client.dataset(run.default_dataset_id).iterate_items():
    print(item)

# 📚 Want to learn more 📖? Go to → https://docs.apify.com/api/client/python/docs/quick-start

```

## CLI example

```bash
echo '{
  "dois": [
    "10.1038/nphys1170",
    "https://doi.org/10.1145/3292500.3330701",
    "10.9999/nonexistent-zzz-000",
    "not-a-doi"
  ],
  "requiredFields": [
    "title",
    "author",
    "issued",
    "type",
    "container-title",
    "publisher"
  ]
}' |
apify call nexgenwatch/crossref-doi-metadata-qa --silent --output-dataset

```

## MCP server setup

```json
{
    "mcpServers": {
        "apify": {
            "type": "http",
            "url": "https://mcp.apify.com/?tools=fetch-actor-details,nexgenwatch/crossref-doi-metadata-qa"
        }
    }
}
```

The hosted server signs you in with OAuth on first connect, so no API token belongs in this config. Clients without OAuth support can send an `Authorization: Bearer <APIFY_API_TOKEN>` header instead, using a token from API & Integrations in Apify Console (https://console.apify.com/settings/integrations).

## OpenAPI specification

Download the OpenAPI definition: https://api.apify.com/v2/actors/B5SwbqyOs9yVYv9qf/builds/g3zozegG5s1m4a6Kp/openapi.json