json_diff

JSON Structural Diff (RFC 6902 Patch) — Compare two JSON texts and return the RFC 6902 JSON Patch (add/remove/replace) operations that turn 'before' into 'after'.

SERVERGateway SOURCEhttps://wingmanprotocol.com/mcp

Low RISK CLASS

Category Read

Parameters 22 required

Recommended Allowedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/com-wingmanprotocol-agent-gateway/json-diff.md

WHAT IT DOES

What json_diff does on Gateway

AI agents call json_diff to retrieve information from Gateway without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

Parameter	Type	Required	Description
`after`	string	Yes	JSON text of the changed document
`before`	string	Yes	JSON text of the original document

Parameters from the server's own tool schema.

RISK

Why json_diff is rated Low

The tool only computes and returns a diff between two JSON inputs. It does not write, modify, delete, or execute anything; it is a read/analysis operation akin to a query or calculation.

From the tool's definition Compare two JSON texts and return the RFC 6902 JSON Patch (add/remove/replace) operations — this is a pure comparison/analysis operation with no side effects

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs json_diff safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Gateway, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For json_diff, this is the rule to start with:

json_diff Allowed

json_diff is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "json_diff": {}
  }
}

ALLOW ONLY THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Gateway, apply this rule, and every json_diff call is checked against it from then on.

FAQ

Questions about json_diff

What does the json_diff tool do? +

JSON Structural Diff (RFC 6902 Patch) — Compare two JSON texts and return the RFC 6902 JSON Patch (add/remove/replace) operations that turn 'before' into 'after'. It is categorised as a Read tool in the Gateway MCP Server, which means it retrieves data without modifying state.

What parameters does json_diff accept? +

json_diff accepts 2 parameters: after, before. Required: after, before. The full parameter table on this page comes from the server's own tool schema.

How do I enforce a policy on json_diff? +

Register the Gateway MCP server in PolicyLayer and add a rule for json_diff: 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 Gateway. Nothing to install.

What risk level is json_diff? +

json_diff is a Read tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit json_diff? +

Yes. Add a rate_limit block to the json_diff 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.

How do I block json_diff completely? +

Set action: deny in the PolicyLayer policy for json_diff. 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.

What MCP server provides json_diff? +

json_diff is provided by the Gateway MCP server (https://wingmanprotocol.com/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

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