Reads a React/Next.js file (.jsx, .tsx, .js, .ts), HTML file (.html), or SVG file (.svg) from disk and returns its JSXN-compressed representation (~40% fewer tokens). Use this instead of reading JSX/TSX files directly when you need to understand component structure, props, and rendering logic. Fo...
Accepts file system path (path)
Part of the Jsx Notation MCP server. Enforce policies on this tool with Intercept, the open-source MCP proxy.
AI agents call read_jsxn to retrieve information from Jsx Notation without modifying any data. This is common in research, monitoring, and reporting workflows where the agent needs context before taking action. Because read operations don't change state, they are generally safe to allow without restrictions -- but you may still want rate limits to control API costs.
Even though read_jsxn only reads data, uncontrolled read access can leak sensitive information or rack up API costs. An agent caught in a retry loop could make thousands of calls per minute. A rate limit gives you a safety net without blocking legitimate use.
Read-only tools are safe to allow by default. No rate limit needed unless you want to control costs.
tools:
read_jsxn:
rules:
- action: allow See the full Jsx Notation policy for all 4 tools.
Agents calling read-class tools like read_jsxn have been implicated in these attack patterns. Read the full case and prevention policy for each:
Other tools in the Read risk category across the catalogue. The same policy patterns (rate-limit, allow) apply to each.
Reads a React/Next.js file (.jsx, .tsx, .js, .ts), HTML file (.html), or SVG file (.svg) from disk and returns its JSXN-compressed representation (~40% fewer tokens). Use this instead of reading JSX/TSX files directly when you need to understand component structure, props, and rendering logic. For full files with imports/hooks/logic, the file-level encoding is used automatically. For .html and .svg files, the HTML encoder is used.. It is categorised as a Read tool in the Jsx Notation MCP Server, which means it retrieves data without modifying state.
Add a rule in your Intercept YAML policy under the tools section for read_jsxn. You can allow, deny, rate-limit, or validate arguments. Then run Intercept as a proxy in front of the Jsx Notation MCP server.
read_jsxn 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 read_jsxn 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 read_jsxn. 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.
read_jsxn is provided by the Jsx Notation MCP server (jsx-notation). 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