Utiliser les ressources Orchestrator dans les serveurs MCP

MCP Servers often need secrets, such as API keys, database credentials, or service tokens, to connect to external systems. Instead of hardcoding these values into MCP Server configuration, you can reference Orchestrator Assets using the %ASSETS/AssetName% syntax.

Asset references are resolved differently depending on the MCP Server type:

• Command and Coded MCP Servers use robot/runtime asset inference. Asset references are resolved as part of the Serverless job runtime before the MCP Server process starts.
• Remote MCP Servers use asset API inference. Asset references in custom headers are resolved through Orchestrator before the request is forwarded to the remote endpoint, without requiring a robot or robot key.

Créer la ressource dans Orchestrator

Accédez à votre dossier dans Orchestrator > Ressources > Créer une ressource. Par exemple:

• Nom : MyApiKey
• Type: Secret, or Credential for username/password pairs
• Valeur: sk-abc123...

La ressource doit se trouver dans le même dossier que le serveur MCP.

Reference assets in Command and Coded MCP Servers

Command and Coded MCP Servers reference assets in environment variables. The location of the environment variables differs:

Type de serveur	Où configurer les variables d’environnement
Commande serveur MCP	Directement sur le serveur MCP, dans le champ Variables d'environnement du formulaire de création ou de modification dans Orchestrator.
Serveur MCP codé	Sur le processus dans Orchestrator: Paramètres > Variables d'environnement.

Dans les deux cas, les entrées prennent la forme KEY=VALUE, avec %ASSETS/AssetName% comme valeur:

API_KEY=%ASSETS/MyApiKey%
DATABASE_URL=%ASSETS/MyDatabaseUrl%
REGION=us-east-1

Les références de ressources et les valeurs simples peuvent être mixtes. Chaque variable va sur sa propre ligne.

Orchestrator stocke les variables d'environnement brutes, y compris les espaces réservés %ASSETS/...% , dans la base de données, chiffrés au repos. Lorsqu'une session démarre, Orchestrator la transmet au runtime sans serveur, ce qui résout les références de ressources à leurs valeurs réelles avant de les transmettre au processus du serveur MCP.

Dans le code du serveur MCP, les variables sont alors disponibles en tant que variables d'environnement standard. Par exemple:

import os
api_key = os.environ.get("API_KEY")  # Resolved to the asset value at runtime

Reference assets in Remote MCP Server headers

Remote MCP Servers do not start a UiPath runtime job, so they do not use robot/runtime asset inference. Instead, you can reference assets in custom HTTP headers. Orchestrator resolves the asset values before forwarding the request to the remote MCP Server.

Use %ASSETS/AssetName% as the full header value:

Authorization: %ASSETS/RemoteBearerToken%
X-Api-Key: %ASSETS/MyApiKey%
X-Region: us-east-1

If the remote endpoint expects a prefix such as Bearer, store the full header value in the asset. For example, store Bearer <token> in the RemoteBearerToken asset, then configure the header as Authorization: %ASSETS/RemoteBearerToken%.

Remote header asset references are resolved through Orchestrator using the caller's UiPath identity and the MCP Server folder context. Orchestrator enforces the required asset permissions and direct API access eligibility. This path works without a robot or robot key.

Remarque :

The caller must have access to the MCP Server folder and permission to view the referenced asset. If the asset is missing, inaccessible, or not eligible for direct API access, the remote MCP request fails instead of forwarding an unresolved placeholder.

Supported asset values

Les comportements suivants s'appliquent à l'inférence de ressources dans les serveurs MCP:

• Les noms de ressource ne sont pas sensibles à la casse dans la syntaxe %ASSETS/...% .
• For Command and Coded MCP Servers, the environment-variable key determines secret masking in the UI. Keys matching patterns such as API_KEY, SECRET, PASSWORD, TOKEN, or Authorization are automatically masked with ****. The %ASSETS/...% reference itself is always visible.
• For Remote MCP Server headers, text, secret, boolean, integer, credential, and Windows credential assets are supported. For credential assets, the password value is used for substitution.
• Configure asset-backed headers only for trusted remote endpoints, because the resolved value is sent to that endpoint.

Remarque :

Key-value-list assets are not supported for MCP Server asset substitution.