osmAPI vs LiteLLM vs OpenRouter

Building with LLMs? You need a gateway that's fast to set up, covers every API, and doesn't eat into your margins. Here's how osmAPI stacks up against the alternatives.

Why osmAPI

API Coverage — osmAPI Leads

osmAPI is one of the only gateways with dedicated endpoints for every OpenAI API — not workarounds through chat completions.

OpenRouter has no dedicated audio endpoints — you must encode audio as base64 in chat messages. OpenRouter has no Realtime WebSocket support at all.

What Only osmAPI Does

Structural Response Healing

LLMs sometimes return broken JSON — markdown-wrapped, truncated, or with syntax errors. osmAPI automatically detects and repairs malformed responses using 5 strategies. Your app never sees broken output.

Neither LiteLLM nor OpenRouter can auto-repair responses. They fail or pass through the broken JSON to your app.

Built-in Web Search

One parameter. Every model gets web search:

curl -X POST "https://api.osmapi.com/v1/chat/completions" \
  -H "Authorization: Bearer $OSM_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model": "gpt-4o", "web_search": true, "messages": [...]}'

Native providers (OpenAI, Anthropic, Google, xAI) use their built-in search. All other models get context injection via Serper — seamlessly, with zero configuration. LiteLLM has partial, buggy support. OpenRouter has none.

Per-Request Cost Breakdown

Every osmAPI response includes exact USD cost in headers and body — broken down by input, output, cached input, web search, and request overhead:

"usage": {
  "cost_usd_total": 0.000245,
  "cost_usd_input": 0.000150,
  "cost_usd_output": 0.000085,
  "cost_usd_cached_input": 0.000000,
  "cost_usd_web_search": 0.000010
}

No dashboard needed — cost tracking is built into every API response.

Interactive Playground

Test any model directly in the browser with osmAPI's built-in playground. Adjust parameters, compare outputs, and prototype — without writing code.

Anthropic-Native Endpoint (/v1/messages)

osmAPI provides a full Anthropic-compatible Messages API — not just OpenAI format. This means tools like Claude Code, Cursor, and any Anthropic SDK work natively.

osmAPI translates between Anthropic and OpenAI formats automatically — thinking blocks become reasoning_effort, Anthropic tools become OpenAI function calls, and vice versa. LiteLLM and OpenRouter mostly pass through without intelligent mapping.

Claude Code setup — 2 lines:

export ANTHROPIC_BASE_URL=https://api.osmapi.com
export ANTHROPIC_API_KEY=osm_YOUR_KEY

Now Claude Code can use any model — GPT-5, Gemini, Llama, DeepSeek — not just Anthropic. Set ANTHROPIC_MODEL=gpt-5 and Claude Code routes through osmAPI seamlessly.

Routing & Reliability

osmAPI's circuit breaker ensures that if Redis goes down, requests continue without caching — zero downtime. No other gateway has this.

Caching

OpenRouter has no server-side response cache. Every identical request hits the provider again. osmAPI caches both standard and streaming responses with timing preservation — reducing latency and cost on repeated queries.

Operational Simplicity

osmAPI gives you the simplicity of a managed service with the power of a self-hosted proxy — without deploying containers, managing databases, or writing configuration files.

The Bottom Line

Get Started in 2 Minutes