Skip to main content
Glama
configcat

ConfigCat MCP Server

Official

update-setting-value-v2

Updates a feature flag or setting value using JSON Patch operations. Modify default value, targeting rules, or percentage evaluation attributes without altering other fields.

Instructions

This endpoint updates the value of a Feature Flag or Setting with a collection of JSON Patch operations in a specified Environment.

Only the defaultValue, targetingRules, and percentageEvaluationAttribute fields are modifiable by this endpoint.

The advantage of using JSON Patch is that you can describe individual update operations on a resource without touching attributes that you don't want to change. It supports collection reordering, so it also can be used for reordering the targeting rules of a Feature Flag or Setting.

For example: We have the following resource of a Feature Flag.

{
  "defaultValue": {
    "boolValue": false
  },
  "targetingRules": [
    {
      "conditions": [
        {
          "userCondition": {
            "comparisonAttribute": "Email",
            "comparator": "sensitiveTextEquals",
            "comparisonValue": {
              "stringValue": "test@example.com"
            }
          }
        }
      ],
      "percentageOptions": [],
      "value": {
        "boolValue": true
      }
    }
  ]
}

If we send an update request body as below:

[
  {
    "op": "replace",
    "path": "/targetingRules/0/value/boolValue",
    "value": true
  }
]

Only the first Targeting Rule's value is going to be set to false and all the other fields are remaining unchanged.

So we get a response like this:

{
  "defaultValue": {
    "boolValue": false
  },
  "targetingRules": [
    {
      "conditions": [
        {
          "userCondition": {
            "comparisonAttribute": "Email",
            "comparator": "sensitiveTextEquals",
            "comparisonValue": {
              "stringValue": "test@example.com"
            }
          }
        }
      ],
      "percentageOptions": [],
      "value": {
        "boolValue": false
      }
    }
  ]
}

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
environmentIdYesThe identifier of the Environment.
settingIdYesThe identifier of the Setting.
reasonNoThe reason note for the Audit Log if the Product's "Config changes require a reason" preference is turned on.
requestBodyYes
Behavior4/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Without annotations, the description transparently explains the partial update behavior, modifiable fields, and includes an example demonstrating the effect. It does not cover error states, authentication, or rate limits, but the core behavior is well communicated.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness3/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is lengthy due to a large JSON example. While the example is helpful, it could be condensed. The structure is logical but not front-loaded for quick scanning.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness3/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The description covers the core purpose and behavior but omits error handling, required permissions, and explicit response format description. Given the complexity and lack of output schema, some gaps remain.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The input schema covers 75% of parameters with descriptions. The description adds significant value by explaining the requestBody structure (JSON Patch array) and illustrating with a concrete example, thereby clarifying the semantics beyond the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states it updates a Feature Flag or Setting using JSON Patch operations. It specifies the modifiable fields (defaultValue, targetingRules, percentageEvaluationAttribute) and distinguishes from siblings like update-setting-value v1 by emphasizing JSON Patch's advantages.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description explains when to use JSON Patch (partial updates, reordering targeting rules) and which fields are modifiable. However, it does not explicitly compare with alternative tools like replace-setting-value-v2 or update-setting, leaving some ambiguity about when to choose this tool.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Install Server

Other Tools

Latest Blog Posts

MCP directory API

We provide all the information about MCP servers via our MCP API.

curl -X GET 'https://glama.ai/api/mcp/v1/servers/configcat/mcp-server'

If you have feedback or need assistance with the MCP directory API, please join our Discord server