Documentation

If your application already talks to OpenAI or Anthropic, you can point it at Viktor and get an AI employee instead of a bare model. The compatible API accepts the standard Chat Completions, Responses, and Messages wire formats and runs a full Viktor agent behind them — with access to your connected tools.

• OpenAI-style base URL: https://api.viktor.com/api/compat/v1
• Anthropic-style base URL: https://api.viktor.com/api/compat
• Model ID: viktor
• Authentication: the same Viktor API keys, with the chat:completions scope granted. API keys require a paid plan or Enterprise.

Quickstart

Grant the chat:completions scope to a key in Settings → API Keys, then swap the base URL, API key, and model in your existing code:

from openai import OpenAI

client = OpenAI(
    base_url="https://api.viktor.com/api/compat/v1",
    api_key="zt_live_sk_...",
)

completion = client.chat.completions.create(
    model="viktor",
    messages=[
        {"role": "user", "content": "Summarize yesterday's Stripe payouts."}
    ],
)
print(completion.choices[0].message.content)

The Anthropic SDK works the same way with base_url="https://api.viktor.com/api/compat".

Endpoints

Streaming is supported on all three chat surfaces.

How it differs from a bare model

• Each call runs the Viktor agent, not a single model invocation. Viktor can use your connected integrations and skills while producing the reply, so calls take longer than a plain LLM call and are capped at 10 minutes.
• Conversation state: Chat Completions and Anthropic Messages are stateless by default — send the full message history on each call, as you would with the upstream APIs. The Responses surface supports previous_response_id to continue a server-side conversation across calls. Chat Completions has the same option as a Viktor extension: every response carries an X-Viktor-Response-Id header, and passing that value as previous_response_id with only the new messages continues the same conversation, including Viktor's earlier tool results.
• System messages are appended to Viktor's own system prompt, never substituted, so Viktor stays Viktor.
• Structured output via response_format with a JSON Schema is supported, as are tool declarations.
• Credits: each call consumes workspace credits like any other Viktor run. See how credits work.
• Rate limits: requests are limited per route and per key owner (all keys of the same owner share one quota), and the limits scale with your workspace plan tier — higher plans get proportionally higher limits. A 429 includes Retry-After; wait for the advertised interval before retrying. See rate limits and retries.

When to use which API

• Use this compatible API when you have existing OpenAI or Anthropic client code and want a drop-in upgrade.
• Use the Public API when you want explicit threads, runs you can poll or cancel, and downloadable file artifacts.
• Use the MCP server when the caller is itself an AI agent.