Searches for a string or regex pattern in all loaded JavaScript sources. Returns matching lines with script ID, URL, and line number. Use get_script_source with startLine/endLine to view full context around matches.
AI agents call search_in_sources to retrieve information from JS Reverse MCP without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
search_in_sources retrieves and queries existing JavaScript source code data without side effects. It is used for analysis and debugging (viewing, not altering). The output is informational (matches, line numbers, URLs). No data is created, modified, deleted, or executed. This is a classic Read operation.
From the tool's definition Tool description states it 'Searches for a string or regex pattern in all loaded JavaScript sources' and 'Returns matching lines' — these are pure query/search operations with no modification, deletion, or execution.
Attacks that exploit this kind of access
Searches for a string or regex pattern in all loaded JavaScript sources. Returns matching lines with script ID, URL, and line number. Use get_script_source with startLine/endLine to view full context around matches. It is categorised as a Read tool in the JS Reverse MCP MCP Server, which means it retrieves data without modifying state.
Register the JS Reverse MCP server in PolicyLayer and add a rule for search_in_sources: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches JS Reverse MCP. Nothing to install.
search_in_sources is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the search_in_sources rule in your PolicyLayer 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 PolicyLayer policy for search_in_sources. 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.
search_in_sources is provided by the JS Reverse MCP server (zhizhuodemao/js-reverse-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.