Policy enforcement gateway for secure access to model context protocol servers
A gateway securely executes model context protocol (“MCP”) processes for artificial intelligence (“AI”) agents by creating nano sandboxes in which the MCP processes execute. A server-sent events (“SSE”) bridge identifies a request to initialize an SSE channel with an MCP server, the request being sent from an MCP client that generates MCP-compliant commands in association with an AI agent. The SSE bridge instantiates a nano sandbox based on a definition extracted from the request, creating a custom and dynamic isolated execution environment. An MCP process is launched within the nano sandbox. The SSE bridge returns a session identifier, and receives a command and the session identifier. The SSE bridge authorizes the command and response by applying security rules, blocking either for non-compliance.
1 . A method for secure model context protocol (“MCP”) access for artificial intelligence (“AI”) agents, comprising:
receiving, at an AI tool gateway, a request from an MCP client to access an MCP server, wherein the request comprises a nano sandbox definition in a hypertext transfer protocol (“HTTP”) header;
authenticating the MCP client using a credential retrieved from a credential store;
verifying that the nano sandbox definition complies with security rules;
instantiating a nano sandbox as an isolated execution environment for the MCP server;
receiving a resource command from the MCP client;
verifying the resource command complies with the security rules;
transmitting the resource command to the MCP server within the nano sandbox;
verifying an output of the MCP server complies with the security rules; and
transmitting the output to the MCP client,
wherein transmitting the resource command to the MCP server comprises writing the resource command to a standard input (“STDIN”) pipe of the MCP server, and wherein verifying the output comprises reading from a standard output (“STDOUT”) pipe of the MCP server.
2 . The method of claim 1 , wherein the credential is at least one of an application programming interface (“API”) key, an OAuth token, or a JSON Web Token (“JWT”).
3 . The method of claim 1 , wherein the credential store encrypts credentials at rest.
4 . The method of claim 1 , wherein the credential store is integrated with an external credential management system.
5 . The method of claim 1 , further comprising automated rotation of the credential based on an expiration policy.
6 . The method of claim 1 , wherein verifying that the nano sandbox definition complies with security rules comprises verifying that system resources and permissions indicated by the nano sandbox definition meet the security rules.
7 . The method of claim 1 , wherein verifying the resource command against the security rules comprises:
checking the resource command for prompt injection;
checking the resource command for code injection; and
comparing the resource command against a whitelist of allowed commands or a blacklist of disallowed commands.
8 . The method of claim 1 , wherein verifying the output of the MCP server complies with the security rules comprises:
checking the output for scripts; and
checking the output for personally identifiable information (“PII”).
9 . The method of claim 1 , further comprising logging the resource command and the output for auditing access.
10 . The method of claim 9 , further comprising monitoring a standard error (“STDERR”) pipe of the MCP server and logging errors from the STDERR pipe.
11 . The method of claim 10 , further comprising detecting a nano sandbox escape attempt based on the errors from the STDERR pipe.
12 . The method of claim 1 , wherein instantiating the nano sandbox comprises executing a bubblewrap command that restricts file system access of the nano sandbox to one or more specified directories.
13 . The method of claim 1 , further comprising injecting the credential into the nano sandbox as an environment variable, wherein the MCP server uses the credential to access an external resource.
14 . The method of claim 1 , wherein the AI tool gateway receives requests from a plurality of MCP clients, and wherein the gateway instantiates a separate nano sandbox for each MCP client of the plurality of MCP clients.
15 . The method of claim 14 , wherein the plurality of MCP clients are associated with different tenants, and wherein each nano sandbox enforces tenant isolation.
16 . The method of claim 1 , wherein the nano sandbox is ephemeral, and further comprising terminating the nano sandbox after transmitting the output to the MCP client.
17 . The method of claim 1 , wherein the security rules are received from an AI platform and stored at the AI tool gateway.
18 . A non-transitory, computer-readable medium containing instructions for secure model context protocol (“MCP”) server access for artificial intelligence (“AI”) agents, wherein the instructions are executed by at least one processor to perform stages comprising:
receiving, at an AI tool gateway, a request from an MCP client to access an MCP server, wherein the request comprises a nano sandbox definition in a hypertext transfer protocol (“HTTP”) header;
authenticating the MCP client using a credential retrieved from a credential store;
verifying that the nano sandbox definition complies with security rules;
instantiating a nano sandbox as an isolated execution environment for the MCP server;
receiving a resource command from the MCP client;
verifying the resource command complies with the security rules;
transmitting the resource command to the MCP server within the nano sandbox;
verifying an output of the MCP server complies with the security rules; and
transmitting the output to the MCP client,
wherein transmitting the resource command to the MCP server comprises writing the resource command to a standard input (“STDIN”) pipe of the MCP server, and wherein verifying the output comprises reading from a standard output (“STDOUT”) pipe of the MCP server.
19 . A system for secure model context protocol (“MCP”) server access for artificial intelligence (“AI”) agents, the system comprising:
at least one physical non-transitory, computer-readable medium comprising instructions; and
an AI tool gateway with at least one processor that executes the instructions to perform stages comprising:
receiving a request from an MCP client to access an MCP server, wherein the request comprises a nano sandbox definition in a hypertext transfer protocol (“HTTP”) header;
authenticating the MCP client using a credential retrieved from a credential store;
verifying that the nano sandbox definition complies with security rules;
instantiating a nano sandbox as an isolated execution environment for the MCP server;
receiving a resource command from the MCP client;
verifying the resource command complies with the security rules;
transmitting the resource command to the MCP server within the nano sandbox;
verifying an output of the MCP server complies with the security rules; and
transmitting the output to the MCP client,
wherein transmitting the resource command to the MCP server comprises writing the resource command to a standard input (“STDIN”) pipe of the MCP server, and wherein verifying the output comprises reading from a standard output (“STDOUT”) pipe of the MCP server.