Run a command in a persistent shell session. Unlike workspace_exec which starts a fresh shell for each command, this maintains state (cwd, env vars, shell history) across calls within the same session. Use sessionId to manage multiple parallel sessions (e.g. one for building, one for testing). Th...
Accepts freeform code/query input (command)
Part of the ArcAgent MCP MCP server. Enforce policies on this tool with Intercept, the open-source MCP proxy.
AI agents invoke workspace_shell to trigger processes or run actions in ArcAgent MCP. Execute operations can have side effects beyond the immediate call -- triggering builds, sending notifications, or starting workflows. Rate limits and argument validation are essential to prevent runaway execution.
workspace_shell can trigger processes with real-world consequences. An uncontrolled agent might start dozens of builds, send mass notifications, or kick off expensive compute jobs. Intercept enforces rate limits and validates arguments to keep execution within safe bounds.
Execute tools trigger processes. Rate-limit and validate arguments to prevent unintended side effects.
tools:
workspace_shell:
rules:
- action: allow
rate_limit:
max: 10
window: 60
validate:
required_args: trueSee the full ArcAgent MCP policy for all 45 tools.
Agents calling execute-class tools like workspace_shell have been implicated in these attack patterns. Read the full case and prevention policy for each:
Other tools in the Execute risk category across the catalogue. The same policy patterns (rate-limit, validate) apply to each.
workspace_shell is one of the high-risk operations in ArcAgent MCP. For the full severity-focused view — only the high-risk tools with their recommended policies — see the breakdown for this server, or browse all high-risk tools across every MCP server.
Run a command in a persistent shell session. Unlike workspace_exec which starts a fresh shell for each command, this maintains state (cwd, env vars, shell history) across calls within the same session. Use sessionId to manage multiple parallel sessions (e.g. one for building, one for testing). The repository is at /workspace.. It is categorised as a Execute tool in the ArcAgent MCP MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Add a rule in your Intercept YAML policy under the tools section for workspace_shell. You can allow, deny, rate-limit, or validate arguments. Then run Intercept as a proxy in front of the ArcAgent MCP MCP server.
workspace_shell is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the workspace_shell rule in your Intercept policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the Intercept policy for workspace_shell. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
workspace_shell is provided by the ArcAgent MCP MCP server (arcagent-mcp). Intercept sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Open source. One binary. Zero dependencies.
npx -y @policylayer/intercept