> ## Documentation Index
> Fetch the complete documentation index at: https://docs.abbyy.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Client Credentials Flow

> Use the OAuth 2.0 Client Credentials flow for ABBYY Vantage machine-to-machine integrations: exchange client ID and secret for an API access token.

export const VantageRegion = ({children}) => {
  const STORAGE_KEY = "abbyy.vantage.region";
  const REGIONS = [{
    code: "eu",
    label: "Europe"
  }, {
    code: "us",
    label: "North America"
  }, {
    code: "au",
    label: "Australia / Asia-Pacific"
  }];
  const [region, setRegion] = useState("eu");
  const [open, setOpen] = useState(false);
  const containerRef = useRef(null);
  const dropdownRef = useRef(null);
  function safeGetSavedRegion() {
    try {
      const saved = typeof window !== "undefined" ? window.localStorage.getItem(STORAGE_KEY) : null;
      const valid = new Set(REGIONS.map(r => r.code));
      return saved && valid.has(saved) ? saved : "eu";
    } catch {
      return "eu";
    }
  }
  function safeSetSavedRegion(code) {
    try {
      if (typeof window !== "undefined") {
        window.localStorage.setItem(STORAGE_KEY, code);
      }
    } catch {}
  }
  function dispatchRegionChanged(code) {
    try {
      if (typeof window !== "undefined") {
        window.dispatchEvent(new CustomEvent("abbyy:region-changed", {
          detail: {
            code
          }
        }));
      }
    } catch {}
  }
  function replaceRegionInString(text, currentRegion) {
    if (typeof text !== "string") return text;
    const hostRegex = /https:\/\/vantage-(eu|us|au)\.abbyy\.com/gi;
    const tokenRegex = /https:\/\/vantage-\[region\]\.abbyy\.com/gi;
    return text.replace(hostRegex, `https://vantage-${currentRegion}.abbyy.com`).replace(tokenRegex, `https://vantage-${currentRegion}.abbyy.com`);
  }
  useEffect(() => {
    setRegion(safeGetSavedRegion());
  }, []);
  useEffect(() => {
    const root = containerRef.current;
    if (!root) return;
    const anchors = root.querySelectorAll("a[href]");
    anchors.forEach(a => {
      const href = a.getAttribute("href");
      if (href) {
        const next = replaceRegionInString(href, region);
        if (next !== href) {
          a.setAttribute("href", next);
        }
      }
    });
    const walker = typeof document !== "undefined" ? document.createTreeWalker(root, NodeFilter.SHOW_TEXT, null) : null;
    if (walker) {
      const toUpdate = [];
      let node = walker.nextNode();
      while (node) {
        const updated = replaceRegionInString(node.nodeValue, region);
        if (updated !== node.nodeValue) {
          toUpdate.push([node, updated]);
        }
        node = walker.nextNode();
      }
      toUpdate.forEach(([textNode, value]) => {
        textNode.nodeValue = value;
      });
    }
  }, [region, children]);
  useEffect(() => {
    const root = containerRef.current;
    if (!root) return;
    const anchors = root.querySelectorAll("a[href]");
    anchors.forEach(a => {
      a.style.fontWeight = "600";
      a.style.textDecoration = "underline";
      a.style.textUnderlineOffset = "2px";
    });
  }, [region, children]);
  useEffect(() => {
    const onRegionChanged = evt => {
      const code = evt && evt.detail && evt.detail.code;
      if (!code || code === region) return;
      setRegion(code);
    };
    if (typeof window !== "undefined") {
      window.addEventListener("abbyy:region-changed", onRegionChanged);
    }
    return () => {
      if (typeof window !== "undefined") {
        window.removeEventListener("abbyy:region-changed", onRegionChanged);
      }
    };
  }, [region]);
  useEffect(() => {
    const onClickAway = e => {
      if (!dropdownRef.current) return;
      if (!dropdownRef.current.contains(e.target)) {
        setOpen(false);
      }
    };
    document.addEventListener("click", onClickAway, true);
    return () => document.removeEventListener("click", onClickAway, true);
  }, []);
  const onSelect = code => {
    setRegion(code);
    safeSetSavedRegion(code);
    dispatchRegionChanged(code);
    setOpen(false);
  };
  const current = REGIONS.find(r => r.code === region) || REGIONS[0];
  return <div className="not-prose">
      <div className="mb-4 inline-flex items-center gap-2" ref={dropdownRef}>
        <span className="text-sm text-zinc-950/80 dark:text-white/80">Tenant Region:</span>
        <div className="relative">
          <button type="button" aria-haspopup="listbox" aria-expanded={open ? "true" : "false"} onClick={() => setOpen(v => !v)} className="h-8 px-3 rounded-md bg-zinc-900/5 dark:bg-white/5 border border-zinc-950/20 dark:border-white/20 text-sm inline-flex items-center gap-2">
            <span className="text-zinc-950 dark:text-white">{current.label}</span>
            <svg width="8" height="24" viewBox="0 -9 3 24" className="transition-transform text-gray-400 overflow-visible dark:text-gray-600 ml-auto" style={{
    transform: open ? "rotate(270deg)" : "rotate(90deg)"
  }}>
              <path d="M0 0L3 3L0 6" fill="none" stroke="currentColor" strokeWidth="1.5" strokeLinecap="round"></path>
            </svg>
          </button>
          {open ? <div role="listbox" className="absolute z-50 left-full top-0 ml-2 w-56 rounded-xl border border-zinc-950/20 dark:border-white/20 bg-white dark:bg-zinc-900 shadow-lg p-2">
              {REGIONS.map(r => {
    const selected = r.code === region;
    return <button key={r.code} type="button" role="option" aria-selected={selected ? "true" : "false"} onClick={() => onSelect(r.code)} className={"w-full flex items-center justify-between px-3 py-2 rounded-lg text-sm hover:bg-zinc-950/5 dark:hover:bg-white/10 text-zinc-950 dark:text-white" + (selected ? " font-medium" : "")}>
                    <span style={selected ? {
      color: "#ff2038"
    } : undefined}>{r.label}</span>
                    <span className={selected ? "ml-3" : "ml-3 invisible"} style={selected ? {
      color: "#ff2038"
    } : undefined}>✓</span>
                  </button>;
  })}
            </div> : null}
        </div>
      </div>
      <div ref={containerRef} className="prose dark:prose-invert max-w-none">{children}</div>
    </div>;
};

This authentication scheme allows an application to obtain an access token by exchanging its application credentials, such as client ID and client secret. This flow is particularly suitable for Machine-to-Machine (M2M) applications, including your application or backend services, as it enables the authentication and authorization of the application itself, rather than that of a user.

To obtain the access token, use the following:

1. A POST request.
2. The `https://vantage-[region].abbyy.com/auth2/connect/token` resource.
3. A `Content-Type` header with the `application/x-www-form-urlencoded` encoding.
4. A request body with the following parameters:

| Parameter                                | Description                                               |
| ---------------------------------------- | --------------------------------------------------------- |
| client\_id                               | Application identifier.                                   |
| client\_secret                           | Secure application key.                                   |
| grant\_type=client\_credentials          | Specifies that the client credentials grant type is used. |
| scope=openid permissions global.wildcard | Specifies the permission scope.                           |

Sample request:

For Windows:

<VantageRegion>
  ```shell theme={null}
  curl --location --request POST "https://vantage-eu.abbyy.com/auth2/connect/token" \
    --data-urlencode "client_id=client_id" \
    --data-urlencode "client_secret=client_secret" \
    --data-urlencode "grant_type=client_credentials" \
    --data-urlencode "scope=openid permissions global.wildcard"
  ```
</VantageRegion>

For Linux:

<VantageRegion>
  ```shell theme={null}
  curl --location --request POST 'https://vantage-eu.abbyy.com/auth2/connect/token' \
    --data-urlencode 'client_id=client_id' \
    --data-urlencode 'client_secret=client_secret' \
    --data-urlencode 'grant_type=client_credentials' \
    --data-urlencode 'scope=openid permissions global.wildcard'
  ```
</VantageRegion>

The server's response to your request will contain the access token:

```json theme={null}
{
  "access_token": "<redacted>",
  "expires_in": 2592000,
  "token_type": "Bearer",
  "scope": "openid permissions global.wildcard"
}
```

For more information about Client Credentials, visit [this link](https://datatracker.ietf.org/doc/html/rfc6749#section-4.4).