Config Targeting

Configure targeting rules for configs to control which variations serve to different contexts. Works the same for both completion and agent mode.

Prerequisites

• LaunchDarkly account with AgentControl enabled
• API access token with write permissions
• Project key and environment key
• Existing config with variations (use configs-create skill)

API Access

Prefer the LaunchDarkly MCP server tools: they authenticate via OAuth and need no token. If a step has no MCP equivalent and you must call the REST API directly, ask the user to paste an API access token for this session and substitute it for {api_token} in the examples below. Do not search environment variables, .env files, or agent/MCP config files for credentials.

Core Concepts

Evaluation Order

Targeting rules evaluate in this order (same as feature flags):

1. Individual targets - Specific context keys (highest priority)
2. Segment rules - Pre-defined segments
3. Custom rules - Attribute-based conditions (evaluated in order)
4. Default rule - Fallthrough for all others
5. Off variation - When targeting is disabled

Semantic Patch API

config targeting uses semantic patch instructions:

PATCH /api/v2/projects/{projectKey}/ai-configs/{configKey}/targeting
Content-Type: application/json; domain-model=launchdarkly.semanticpatch

Key Concepts

• variationId: UUIDs, not keys. Always fetch targeting first to get IDs.
• Weights: Thousandths (50000 = 50%, 100000 = 100%)
• Clause logic: Multiple clauses = AND, multiple values = OR
• Null attributes: Rules with null/missing attributes are skipped

Workflow

Step 1: Get Targeting (with Variation IDs)

curl -X GET "https://app.launchdarkly.com/api/v2/projects/{projectKey}/ai-configs/{configKey}/targeting" \
  -H "Authorization: {api_token}" \
  -H "LD-API-Version: beta"

Response includes variations array with _id (UUID) for each variation.

Step 2: Edit the Default Rule

Edit the default rule to serve the variation you created.

Important: The turnTargetingOn instruction does not work for configs. Use updateFallthroughVariationOrRollout instead.

# First, get variation IDs from Step 1 response
# Then set fallthrough to the enabled variation (e.g., "Default" variation)
curl -X PATCH "https://app.launchdarkly.com/api/v2/projects/{projectKey}/ai-configs/{configKey}/targeting" \
  -H "Authorization: {api_token}" \
  -H "Content-Type: application/json; domain-model=launchdarkly.semanticpatch" \
  -H "LD-API-Version: beta" \
  -d '{
    "environmentKey": "production",
    "instructions": [{
      "kind": "updateFallthroughVariationOrRollout",
      "variationId": "your-enabled-variation-uuid"
    }]
  }'

Step 3: Add Targeting Rules

Attribute-based rule:

curl -X PATCH "https://app.launchdarkly.com/api/v2/projects/{projectKey}/ai-configs/{configKey}/targeting" \
  -H "Authorization: {api_token}" \
  -H "Content-Type: application/json; domain-model=launchdarkly.semanticpatch" \
  -H "LD-API-Version: beta" \
  -d '{
    "environmentKey": "production",
    "instructions": [{
      "kind": "addRule",
      "clauses": [{
        "contextKind": "user",
        "attribute": "selectedModel",
        "op": "contains",
        "values": ["sonnet"],
        "negate": false
      }],
      "variation": 0
    }]
  }'

Percentage rollout:

curl -X PATCH "..." \
  -d '{
    "environmentKey": "production",
    "instructions": [{
      "kind": "addRule",
      "clauses": [{
        "contextKind": "user",
        "attribute": "tier",
        "op": "in",
        "values": ["premium"],
        "negate": false
      }],
      "percentageRolloutConfig": {
        "contextKind": "user",
        "bucketBy": "key",
        "variations": [
          {"variation": 0, "weight": 60000},
          {"variation": 1, "weight": 40000}
        ]
      }
    }]
  }'

Set fallthrough (default rule):

curl -X PATCH "..." \
  -d '{
    "environmentKey": "production",
    "instructions": [{
      "kind": "updateFallthroughVariationOrRollout",
      "variationId": "fallback-variation-uuid"
    }]
  }'

Python Implementation

import requests
import os
from typing import Dict, List, Optional

class AIConfigTargeting:
    """Manager for config targeting rules"""

    def __init__(self, api_token: str, project_key: str):
        self.api_token = api_token
        self.project_key = project_key
        self.base_url = "https://app.launchdarkly.com/api/v2"

    def get_targeting(self, config_key: str) -> Optional[Dict]:
        """Get current targeting with variation IDs."""
        url = f"{self.base_url}/projects/{self.project_key}/ai-configs/{config_key}/targeting"

        response = requests.get(url, headers={
            "Authorization": self.api_token,
            "LD-API-Version": "beta"
        })

        if response.status_code == 200:
            return response.json()
        print(f"[ERROR] {response.status_code}: {response.text}")
        return None

    def get_variation_id(self, config_key: str, variation_key: str) -> Optional[str]:
        """Look up variation UUID from key or name."""
        targeting = self.get_targeting(config_key)
        if targeting:
            for var in targeting.get("variations", []):
                if var.get("key") == variation_key or var.get("name") == variation_key:
                    return var.get("_id")
        return None

    def update_targeting(self, config_key: str, environment: str,
                         instructions: List[Dict], comment: str = "") -> Optional[Dict]:
        """Send semantic patch instructions."""
        url = f"{self.base_url}/projects/{self.project_key}/ai-configs/{config_key}/targeting"

        payload = {"environmentKey": environment, "instructions": instructions}
        if comment:
            payload["comment"] = comment

        response = requests.patch(url, headers={
            "Authorization": self.api_token,
            "Content-Type": "application/json; domain-model=launchdarkly.semanticpatch",
            "LD-API-Version": "beta"
        }, json=payload)

        if response.status_code == 200:
            return response.json()
        print(f"[ERROR] {response.status_code}: {response.text}")
        return None

    def enable_config(self, config_key: str, environment: str,
                      variation_key: str = "default") -> bool:
        """
        Enable a config by setting fallthrough to an enabled variation.

        Note: turnTargetingOn doesn't work for configs. Instead, set the
        fallthrough from the disabled variation (index 0) to an enabled one.
        """
        variation_id = self.get_variation_id(config_key, variation_key)
        if not variation_id:
            print(f"[ERROR] Variation '{variation_key}' not found")
            return False
        return self.set_fallthrough(config_key, environment, variation_id)

    def add_rule(self, config_key: str, environment: str,
                 clauses: List[Dict], variation: int,
                 description: str = "") -> bool:
        """Add targeting rule serving a specific variation index."""
        instruction = {
            "kind": "addRule",
            "clauses": clauses,
            "variation": variation
        }
        if description:
            instruction["description"] = description

        result = self.update_targeting(config_key, environment,
            [instruction], f"Add rule: {description}")
        if result:
            print(f"[OK] Rule added")
            return True
        return False

    def add_rollout_rule(self, config_key: str, environment: str,
                         clauses: List[Dict],
                         weights: List[Dict],
                         bucket_by: str = "key") -> bool:
        """
        Add percentage rollout rule.

        weights: [{"variation": 0, "weight": 50000}, {"variation": 1, "weight": 50000}]
        """
        result = self.update_targeting(config_key, environment, [{
            "kind": "addRule",
            "clauses": clauses,
            "percentageRolloutConfig": {
                "contextKind": "user",
                "bucketBy": bucket_by,
                "variations": weights
            }
        }], "Add percentage rollout")
        if result:
            print(f"[OK] Rollout rule added")
            return True
        return False

    def set_fallthrough(self, config_key: str, environment: str,
                        variation_id: str) -> bool:
        """Set default (fallthrough) variation by UUID."""
        result = self.update_targeting(config_key, environment, [{
            "kind": "updateFallthroughVariationOrRollout",
            "variationId": variation_id
        }], "Set fallthrough")
        if result:
            print(f"[OK] Fallthrough set")
            return True
        return False

    def target_individuals(self, config_key: str, environment: str,
                          context_keys: List[str], variation: int,
                          context_kind: str = "user") -> bool:
        """Target specific context keys."""
        result = self.update_targeting(config_key, environment, [{
            "kind": "addTargets",
            "variation": variation,
            "contextKind": context_kind,
            "values": context_keys
        }], f"Target {len(context_keys)} individuals")
        if result:
            print(f"[OK] Individual targets added")
            return True
        return False

    def target_segment(self, config_key: str, environment: str,
                      segment_keys: List[str], variation: int) -> bool:
        """Target a segment."""
        result = self.update_targeting(config_key, environment, [{
            "kind": "addRule",
            "clauses": [{
                "attribute": "segmentMatch",
                "contextKind": "",  # Leave blank for segments
                "op": "segmentMatch",
                "values": segment_keys,
                "negate": False
            }],
            "variation": variation
        }], f"Target segments: {segment_keys}")
        if result:
            print(f"[OK] Segment targeting added")
            return True
        return False

    def clear_rules(self, config_key: str, environment: str) -> bool:
        """Remove all targeting rules."""
        result = self.update_targeting(config_key, environment,
            [{"kind": "replaceRules", "rules": []}], "Clear all rules")
        if result:
            print(f"[OK] All rules cleared")
            return True
        return False

Instruction Reference

Note: turnTargetingOn and turnTargetingOff do not work for configs. Configs have targeting enabled by default. To "enable" a config, set the fallthrough to an enabled variation using updateFallthroughVariationOrRollout.

Rules

Fallthrough

Individual Targets

Operators Reference

Clause Structure

{
  "contextKind": "user",
  "attribute": "email",
  "op": "endsWith",
  "values": [".edu"],
  "negate": false
}

• Multiple clauses = AND (all must match)
• Multiple values = OR (any can match)
• negate: true inverts the operator

Rollout Types

Manual Percentage Rollout

{
  "percentageRolloutConfig": {
    "contextKind": "user",
    "bucketBy": "key",
    "variations": [
      {"variation": 0, "weight": 50000},
      {"variation": 1, "weight": 50000}
    ]
  }
}

Progressive Rollout

{
  "progressiveRolloutConfig": {
    "contextKind": "user",
    "controlVariation": 1,
    "endVariation": 0,
    "steps": [
      {"rolloutWeight": 1000, "duration": {"quantity": 4, "unit": "hour"}},
      {"rolloutWeight": 5000, "duration": {"quantity": 4, "unit": "hour"}},
      {"rolloutWeight": 10000, "duration": {"quantity": 4, "unit": "hour"}}
    ]
  }
}

Guarded Rollout

{
  "guardedRolloutConfig": {
    "randomizationUnit": "user",
    "stages": [
      {"rolloutWeight": 1000, "monitoringWindowMilliseconds": 17280000},
      {"rolloutWeight": 5000, "monitoringWindowMilliseconds": 17280000}
    ],
    "metrics": [{
      "metricKey": "error-rate",
      "onRegression": {"rollback": true},
      "regressionThreshold": 0.01
    }]
  }
}

Common Patterns

Model Routing by Attribute

# Route based on selectedModel context attribute
targeting.add_rule(
    config_key="model-selector",
    environment="production",
    clauses=[{
        "contextKind": "user",
        "attribute": "selectedModel",
        "op": "contains",
        "values": ["sonnet"],
        "negate": False
    }],
    variation=0,  # Sonnet variation index
    description="Route sonnet requests"
)

Tier-Based Variation

targeting.add_rule(
    config_key="chat-assistant",
    environment="production",
    clauses=[{
        "contextKind": "user",
        "attribute": "tier",
        "op": "in",
        "values": ["premium", "enterprise"],
        "negate": False
    }],
    variation=0  # Premium model variation
)

Segment Targeting

targeting.target_segment(
    config_key="chat-assistant",
    environment="production",
    segment_keys=["beta-testers"],
    variation=1  # Experimental variation
)

Error Handling

Next Steps

After configuring targeting:

1. Provide config URL:

   https://app.launchdarkly.com/projects/{projectKey}/ai-configs/{configKey}
   

2. Monitor performance with built-in-metrics
3. Attach judges with online-evals
4. Set up guarded rollouts for automatic regression detection

Related Skills

• configs-create - Create configs with variations
• configs-variations - Manage variations
• online-evals - Attach judges
• segments - Create segments for targeting

Other Resources

• Target with AgentControl
• Targeting Rules
• JSON Targeting
• Guarded Rollouts