Monitoring Aider with Vigilmon: LLM API Health, Web UI Uptime & AI Pair Programmer Availability

Aider is an open-source AI pair programmer that runs in the terminal, maps your codebase, and applies multi-file edits suggested by Claude, GPT-4, Gemini, or any OpenAI-compatible model. It auto-commits changes with meaningful git messages and includes a web UI mode for browser-based sessions. Developer productivity sessions with Aider depend on the LLM API being reachable — a mid-session outage drops the context window and forces a cold restart. Vigilmon gives you external visibility into the LLM backends Aider calls, the Aider web UI if you run it as a shared service, and the model APIs your team has standardized on.

What You'll Build

• HTTP monitors for the LLM API endpoints Aider routes requests to
• A monitor for the Aider web UI if you host it as a shared service
• SSL certificate monitoring for model API domains
• An alerting setup that pinpoints which LLM backend is down when Aider sessions fail

Prerequisites

• Aider installed (pip install aider-chat) with a configured LLM API key
• Knowledge of which model you use (Claude, GPT-4, Gemini, or a local/self-hosted model)
• A free account at vigilmon.online

Step 1: Identify Your Aider LLM Backend

Aider uses the ANTHROPIC_API_KEY, OPENAI_API_KEY, GEMINI_API_KEY, or OPENAI_API_BASE environment variable to determine its backend. Check which model Aider is using in your .aider.conf.yml or ~/.aider.conf.yml:

# Example .aider.conf.yml
model: claude-sonnet-4-5
anthropic-api-key: ${ANTHROPIC_API_KEY}

Or for OpenAI-compatible local servers:

model: ollama/llama3
openai-api-base: http://localhost:11434/v1

Each backend maps to a monitoring target. Identify your primary model API endpoint before configuring monitors.

Step 2: Monitor the Anthropic API (for Claude models)

Aider works best with Claude models (its primary recommendation). Monitor the Anthropic API:

curl -I https://api.anthropic.com

1. Log in to Vigilmon → Add Monitor → HTTP.
2. URL: https://api.anthropic.com.
3. Check interval: 60 seconds.
4. Response timeout: 15 seconds.
5. Expected status: 200.
6. Label: Anthropic API (Aider backend).
7. Click Save.

This monitor catches Anthropic API outages that cause Aider to fail with Unexpected API response errors and drop in-progress sessions.

Step 3: Monitor the OpenAI API (for GPT-4 or GPT-4o)

If your team runs Aider with OpenAI models, monitor their API:

1. Add Monitor → HTTP.
2. URL: https://api.openai.com/v1/models.
3. Check interval: 60 seconds.
4. Response timeout: 15 seconds.
5. Expected status: 200.
6. Label: OpenAI API (Aider backend).
7. Click Save.

If Aider is configured with --openai-api-base pointing to a custom endpoint (OpenRouter, LiteLLM, a corporate proxy), monitor that URL instead of api.openai.com.

Step 4: Monitor a Self-Hosted or Local Model Backend

Aider supports Ollama, LM Studio, llama.cpp, and any OpenAI-compatible server via --openai-api-base. For shared team servers hosting local models:

# Ollama health check
curl http://your-model-server:11434/api/tags

# LM Studio / llama.cpp / vLLM (OpenAI-compatible)
curl http://your-model-server:8000/v1/models

For an Ollama backend:

1. Add Monitor → HTTP.
2. URL: http://your-model-server:11434/api/tags.
3. Check interval: 60 seconds.
4. Response timeout: 10 seconds.
5. Expected status: 200.
6. Keyword: models.
7. Label: Ollama server (Aider local backend).
8. Click Save.

For an OpenAI-compatible local server:

1. Add Monitor → HTTP.
2. URL: http://your-model-server:8000/v1/models.
3. Check interval: 60 seconds.
4. Expected status: 200.
5. Label: Local model server (Aider OpenAI-compatible).
6. Click Save.

Step 5: Monitor the Aider Web UI

Aider includes a web UI mode (aider --gui) that opens a browser-based interface. If your team runs Aider's web UI as a shared service (e.g., on an internal server), monitoring its availability catches process crashes:

# Default Aider web UI port
curl http://your-aider-host:8501

1. Add Monitor → HTTP.
2. URL: http://your-aider-host:8501.
3. Check interval: 2 minutes.
4. Response timeout: 10 seconds.
5. Expected status: 200.
6. Keyword: Aider.
7. Label: Aider web UI.
8. Click Save.

The Aider web UI is based on Gradio and runs on port 8501 by default. If you've changed the port with --gui-port, adjust the URL accordingly.

Step 6: Monitor an LLM Proxy Gateway

Teams often route Aider through a gateway (LiteLLM proxy, OpenRouter, or a corporate LLM proxy) to manage API keys, enforce model policies, and track token usage across developers. Monitor your gateway's health endpoint:

# LiteLLM proxy health
curl https://your-llm-proxy.example.com/health

# OpenRouter API health
curl -I https://openrouter.ai/api/v1/models

For a LiteLLM proxy:

1. Add Monitor → HTTP.
2. URL: https://your-llm-proxy.example.com/health.
3. Check interval: 60 seconds.
4. Expected status: 200.
5. Keyword: healthy.
6. Label: LLM proxy (Aider gateway).
7. Click Save.

Step 7: Monitor SSL Certificates

LLM API calls from Aider require valid TLS. An expired certificate on a model API domain causes Aider to fail with SSL verification errors. Monitor certificates for any domain your Aider deployment calls:

1. Add Monitor → SSL Certificate.
2. Domain: api.anthropic.com.
3. Alert when expiry is within: 30 days.
4. Alert again: 14 days, 7 days, 3 days, 1 day.
5. Click Save.

For self-hosted model servers with custom domains:

1. Add Monitor → SSL Certificate.
2. Domain: your-model-server.example.com.
3. Alert when expiry is within: 30 days.
4. Click Save.

Step 8: Configure Alerting

In Vigilmon under Settings → Notifications, configure your alert channels:

| Monitor | Trigger | Action | |---|---|---| | Anthropic API | Non-200 or timeout | Claude sessions drop; switch to backup model or wait for recovery | | OpenAI API | Non-200 or timeout | GPT sessions fail; check openai.com/status | | Local model server | Non-200 or keyword missing | Restart Ollama/LM Studio; check GPU memory | | Aider web UI | Non-200 or keyword missing | Web UI process crashed; restart aider --gui service | | LLM proxy | Non-200 or keyword missing | All Aider routes blocked; check proxy logs | | SSL certificate | < 30 days to expiry | SSL errors will follow on expiry; renew proactively |

Alert routing: Send LLM API alerts to a developer tools channel. A backend outage affects every developer running Aider simultaneously, making team-wide notification appropriate.

Common Aider Failure Modes and What Vigilmon Catches

| Scenario | Vigilmon monitor | |---|---| | Anthropic API outage | API monitor fires; Aider returns Connection error | | OpenAI quota exceeded (429) | API monitor fires; all GPT sessions fail | | Local model server OOM crash | Model server monitor fires; GPU process killed | | Aider web UI process exits | Web UI monitor fires; browser sessions return connection refused | | LLM proxy misconfigured after deploy | Proxy health monitor fires; all routed models fail | | SSL expiry on model API domain | SSL monitor alerts at 30 days; Aider fails with TLS errors | | DNS failure for model API | Monitor fires from Vigilmon external check | | Corporate firewall blocks LLM API | Vigilmon external check passes; only internal users affected |

Aider's value as an AI pair programmer depends on maintaining a live connection to the LLM backend throughout a coding session. Vigilmon gives you external visibility into every backend Aider can target — cloud APIs, local model servers, LLM gateways, and the web UI — so you know which layer failed when sessions start erroring and can recover or redirect developers to a working backend quickly.

Start monitoring Aider's backends in under 5 minutes — register free at vigilmon.online.