extract_json
Extract and parse JSON objects/arrays from messy text (e.g., model output with prose and code fences). Returns parsed JSON.
This record as markdown: /tools/cowork-os/extract-json.md
What extract_json does on CoWork OS
AI agents call extract_json to retrieve information from CoWork OS without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
Why extract_json is rated Low
This tool performs text parsing and JSON extraction—a pure data retrieval and transformation operation. It reads input text, identifies JSON structures, and returns the parsed result. There is no creation, modification, deletion, code execution, or financial impact. The operation is idempotent and non-destructive, making it a Read category tool with low severity.
From the tool's definition Tool description states it 'Extract and parse JSON objects/arrays from messy text' and 'Returns parsed JSON'. The verb 'extract' and 'parse' indicate data retrieval and transformation operations with no side effects on underlying systems or data stores.
Attacks that exploit this kind of access
The rule that runs extract_json safely
PolicyLayer is an MCP gateway: it sits between your AI agents and CoWork OS, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For extract_json, this is the rule to start with:
extract_json is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.
The button opens the PolicyLayer dashboard: create your workspace, connect CoWork OS, apply this rule, and every extract_json call is checked against it from then on.
Questions about extract_json
Extract and parse JSON objects/arrays from messy text (e.g., model output with prose and code fences). Returns parsed JSON. It is categorised as a Read tool in the CoWork OS MCP Server, which means it retrieves data without modifying state.
Register the CoWork OS MCP server in PolicyLayer and add a rule for extract_json: 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 CoWork OS. Nothing to install.
extract_json 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 extract_json 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 extract_json. 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.
extract_json is provided by the CoWork OS MCP server (CoWork-OS/CoWork-OS). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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