Use the Claude API via RunAPI with a model skill, unified auth, and pay-as-you-go pricing.
# Base URL
https://runapi.ai
# Endpoints
POST /v1/chat/completions
POST /v1/responses
POST /v1/messages
POST /v1beta/models/{model}:generateContent
POST /v1beta/models/{model}:streamGenerateContent
curl https://runapi.ai/v1/messages \
-H "Authorization: Bearer $RUNAPI_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "claude-sonnet-5",
"max_tokens": 1024,
"messages": [
{
"role": "user",
"content": "Review this pull request for security vulnerabilities, performance issues, and suggest concrete improvements."
}
]
}'import anthropic
client = anthropic.Anthropic(
base_url="https://runapi.ai",
api_key="your-runapi-key"
)
message = client.messages.create(
model="claude-sonnet-5",
max_tokens=1024,
messages=[{"role": "user", "content": "Review this pull request for security vulnerabilities, performance issues, and suggest concrete improvements."}]
)import Anthropic from "@anthropic-ai/sdk";
const client = new Anthropic({
baseURL: "https://runapi.ai",
apiKey: "your-runapi-key"
});
const message = await client.messages.create({
model: "claude-sonnet-5",
max_tokens: 1024,
messages: [{ role: "user", content: "Review this pull request for security vulnerabilities, performance issues, and suggest concrete improvements." }]
});Claude is Anthropic's large language model family available in Opus, Sonnet, and Haiku tiers, designed for nuanced reasoning, long-context analysis, and code generation. It emphasizes accuracy, instruction following, and predictable outputs.
| Endpoint | Protocol |
|---|---|
POST /v1/chat/completions | OpenAI compatible |
POST /v1/responses | OpenAI Responses |
POST /v1/messages | Anthropic compatible |
POST /v1beta/models/{model}:generateContent | Gemini generateContent |
POST /v1beta/models/{model}:streamGenerateContent | Gemini streamGenerateContent |
| Variant | Billing | Pricing | |
|---|---|---|---|
| claude-fable-5 | 1K tokens | Input $10.00 / 1M tokens | Output $50.00 / 1M tokens | View → |
| claude-fable-5-1 | 1K tokens | Input $10.00 / 1M tokens | Output $50.00 / 1M tokens | View → |
| claude-haiku-4-5-20251001 | 1K tokens | Input $0.60 / 1M tokens | Output $3.00 / 1M tokens | View → |
| claude-opus-4-1-20250805 | 1K tokens | Input $9.00 / 1M tokens | Output $45.00 / 1M tokens | View → |
| claude-opus-4-5-20251101 | 1K tokens | Input $3.00 / 1M tokens | Output $15.00 / 1M tokens | View → |
| claude-opus-4-6 | 1K tokens | Input $3.00 / 1M tokens | Output $15.00 / 1M tokens | View → |
| claude-opus-4-7 | 1K tokens | Input $3.00 / 1M tokens | Output $15.00 / 1M tokens | View → |
| claude-opus-4-8 | 1K tokens | Input $3.00 / 1M tokens | Output $15.00 / 1M tokens | View → |
| claude-opus-5 | 1K tokens | Input $3.00 / 1M tokens | Output $15.00 / 1M tokens | View → |
| claude-sonnet-4-5-20250929 | 1K tokens | Input $1.80 / 1M tokens | Output $9.00 / 1M tokens | View → |
| claude-sonnet-4-6 | 1K tokens | Input $1.80 / 1M tokens | Output $9.00 / 1M tokens | View → |
| claude-sonnet-5 | 1K tokens | Input $1.36 / 1M tokens | Output $6.78 / 1M tokens | View → |
| Endpoint | Resolution | Duration | Price | |
|---|---|---|---|---|
| message | — | — | Input $10.00 / 1M tokens | Output $50.00 / 1M tokens |
Prices shown for claude-fable-5. Other variants retain their own endpoint pricing.
Sign up and generate an API key from the dashboard.
Choose the version that best matches your quality and cost requirements.
Submit your prompt and parameters to the model's documented endpoint.
Poll the task or set a webhook, then download the completed output.
Claude is Anthropic's LLM family, spanning Opus (frontier), Sonnet (balanced), and Haiku (fast). Through RunAPI, all Claude variants share the same API shape and per-token billing.
A single RunAPI API key unlocks the whole model catalog across all providers. No separate accounts to create, no API keys to rotate per integration, and no credential management overhead. Add a new model to your app by changing one parameter.
Per-call pricing in USD, billed monthly into a single invoice. No subscription tiers, no minimum spend, and failed generations are never charged. The pricing page and check_pricing API show exact costs before you commit to a model.
Typed schemas, parameter constraints, and setup notes are packaged in the model skill so your implementation starts from the right contract. The skill loads into Claude Code, Codex, Gemini CLI, Cursor, and VS Code — your agent knows the correct request shape before you write a line of code.
Most Claude models support 200K tokens of context, with 1M-token context available on the latest Opus and Sonnet models. Pricing is the same per-token regardless of context size.
Extended thinking lets Claude reason step-by-step before answering. Thinking tokens are billed as output tokens and count toward the context limit.
Opus is the most capable for complex reasoning. Sonnet balances quality and speed. Haiku is the fastest and cheapest for high-throughput tasks.
Yes — Claude can call tools, execute code, search the web, and fetch URLs. Tool use is generally available with no beta header required.
Yes — cache reads are charged at roughly 10% of the standard input rate, significantly reducing cost for repeated contexts.
Pick the cheapest variant that meets your quality bar. Most teams start on the fast variant and graduate to pro for production.