---
name: service-registry
description: Registers external services with health checks, central config, and unified execution. Use when integrating multiple external services needing coordination.
alwaysApply: false
category: infrastructure
tags:
- services
- registry
- execution
- health-checks
- integration
dependencies:
- quota-management
- usage-logging
tools: []
provides:
  infrastructure:
  - service-registry
  - health-monitoring
  - execution-engine
  patterns:
  - service-discovery
  - unified-execution
  - configuration-management
usage_patterns:
- multi-service-integration
- service-health-checks
- unified-execution
- configuration-management
complexity: intermediate
model_hint: standard
estimated_tokens: 550
progressive_loading: true
modules:
- modules/service-config.md
- modules/execution-patterns.md
---

# Service Registry

## Overview

A registry pattern for managing connections to external services. Handles configuration, health checking, and execution across multiple service integrations.

## When To Use

- Managing multiple external services.
- Need consistent execution interface.
- Want health monitoring across services.
- Building service failover logic.

## When NOT To Use

- Single service integration without registry needs

## Core Concepts

### Service Configuration

```python
@dataclass
class ServiceConfig:
    name: str
    command: str
    auth_method: str  # "api_key", "oauth", "token"
    auth_env_var: str
    quota_limits: dict
    models: list[str] = field(default_factory=list)
```
**Verification:** Run the command with `--help` flag to verify availability.

### Execution Result

```python
@dataclass
class ExecutionResult:
    success: bool
    stdout: str
    stderr: str
    exit_code: int
    duration: float
    tokens_used: int
```
**Verification:** Run the command with `--help` flag to verify availability.

## Quick Start

### Register Services
```python
from leyline.service_registry import ServiceRegistry

registry = ServiceRegistry()

registry.register(
    "gemini",
    ServiceConfig(
        name="gemini",
        command="gemini",
        auth_method="api_key",
        auth_env_var="GEMINI_API_KEY",
        quota_limits={"rpm": 60, "daily": 1000},
    ),
)
```
**Verification:** Run the command with `--help` flag to verify availability.

### Execute via Service
```python
result = registry.execute(
    service="gemini",
    prompt="Analyze this code",
    files=["src/main.py"],
    model="gemini-3-pro",
)

if result.success:
    print(result.stdout)
```
**Verification:** Run the command with `--help` flag to verify availability.

### Health Checks
```python
# Check single service
status = registry.health_check("gemini")

# Check all services
all_status = registry.health_check_all()
for service, healthy in all_status.items():
    print(f"{service}: {'OK' if healthy else 'FAILED'}")
```
**Verification:** Run the command with `--help` flag to verify availability.

## Service Selection

### Auto-Selection
```python
# Select best service for task
service = registry.select_service(
    requirements={"large_context": True, "fast_response": False}
)
```
**Verification:** Run the command with `--help` flag to verify availability.

### Failover Pattern
```python
def execute_with_failover(prompt: str, files: list) -> ExecutionResult:
    for service in registry.get_healthy_services():
        result = registry.execute(service, prompt, files)
        if result.success:
            return result
    raise AllServicesFailedError()
```
**Verification:** Run the command with `--help` flag to verify availability.

## Integration Pattern

```yaml
# In your skill's frontmatter
dependencies: [leyline:service-registry]
```
**Verification:** Run the command with `--help` flag to verify availability.

## Detailed Resources

- **Service Config**: See `modules/service-config.md` for configuration options.
- **Execution Patterns**: See `modules/execution-patterns.md` for advanced usage.

## Exit Criteria

- Services registered with configuration.
- Health checks passing.
- Execution results properly handled.