Apply a V4A-format patch to your workspace. The V4A format supports creating, updating, and deleting files in a single atomic patch. Format: ``` *** Begin Patch *** Update File: src/main.ts @@ context anchor line -removed line +added line kept line *** Add File: src/new.ts +line 1 +line 2 *** De...
Single-target operation
Part of the ArcAgent MCP MCP server. Enforce policies on this tool with Intercept, the open-source MCP proxy.
AI agents use workspace_apply_patch to create or modify resources in ArcAgent MCP. Write operations carry medium risk because an autonomous agent could trigger bulk unintended modifications. Rate limits prevent a single agent session from making hundreds of changes in rapid succession. Argument validation ensures the agent passes expected values.
Without a policy, an AI agent could call workspace_apply_patch repeatedly, creating or modifying resources faster than any human could review. Intercept's rate limiting ensures write operations happen at a controlled pace, and argument validation catches malformed or unexpected inputs before they reach ArcAgent MCP.
Write tools can modify data. A rate limit prevents runaway bulk operations from AI agents.
tools:
workspace_apply_patch:
rules:
- action: allow
rate_limit:
max: 30
window: 60See the full ArcAgent MCP policy for all 45 tools.
Agents calling write-class tools like workspace_apply_patch have been implicated in these attack patterns. Read the full case and prevention policy for each:
Other tools in the Write risk category across the catalogue. The same policy patterns (rate-limit, validate) apply to each.
Apply a V4A-format patch to your workspace. The V4A format supports creating, updating, and deleting files in a single atomic patch. Format: ``` *** Begin Patch *** Update File: src/main.ts @@ context anchor line -removed line +added line kept line *** Add File: src/new.ts +line 1 +line 2 *** Delete File: src/old.ts *** End Patch ``` Context lines (prefixed with space) and @@ anchors locate the edit position. No line numbers needed.. It is categorised as a Write tool in the ArcAgent MCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Add a rule in your Intercept YAML policy under the tools section for workspace_apply_patch. You can allow, deny, rate-limit, or validate arguments. Then run Intercept as a proxy in front of the ArcAgent MCP MCP server.
workspace_apply_patch is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the workspace_apply_patch 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_apply_patch. 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_apply_patch 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