Models

Use GET /v1/models to discover the models enabled for your environment. It requires an active key with run:write. Discovery does not generate content or incur scan usage.

curl https://api.zaun.ai/v1/models \
  -H "Authorization: Bearer $ZAUN_API_KEY"

Use the returned id in POST /v1/responses. Zaun handles model routing internally. Do not send transport names, deployment IDs, or region prefixes.

{
  "id": "claude-sonnet-5",
  "object": "model",
  "created": 0,
  "owned_by": "zaun",
  "zaun": {
    "max_output_tokens": 128000,
    "sampling": "disabled",
    "effort": {"levels": ["low", "medium", "high", "xhigh", "max"], "default": "high"},
    "pricing": {
      "currency": "usd",
      "input_micros_per_million": 2200000,
      "output_micros_per_million": 11100000,
      "cache_read_micros_per_million": 220000,
      "cache_write_5m_micros_per_million": 2750000,
      "cache_write_1h_micros_per_million": 4400000
    }
  }
}

owned_by identifies the Zaun-managed route. created: 0 means its creation timestamp is not tracked. Prices are integer USD microdollars per million tokens; 1,000,000 microdollars is $1. Protected-token assessment charges are additional; see Limits & errors.

effort lists the reasoning.effort levels the model accepts and the level it runs at when a request names none. It is null for models that take no effort; sending one to those returns 422. See Responses.

Model IDs#

Image parts are accepted only by the Claude routes. Other routes return unsupported_content for a request with images; see Scan an image.

Claude and GPT-6 deployments expose their documented 128K native output budget. Other providers retain their configured model-specific limits. Use zaun.max_output_tokens from GET /v1/models for the cap enforced by your environment.

Availability depends on your environment. Only IDs returned by discovery are enabled. An empty catalog returns {"object":"list","data":[]}. Unconfigured models return 422 before assessment or generation.

Create a response#

curl https://api.zaun.ai/v1/responses \
  -H "Authorization: Bearer $ZAUN_API_KEY" \
  -H 'Content-Type: application/json' \
  -d '{"model":"claude-opus-5-5","input":"Explain least privilege in one sentence.","max_output_tokens":128}'

Use a new idempotency key when selecting a different model. For limits and unsupported options, see Responses. Review model-specific retention and subprocessor policies before sending content.

Cerebras GPT-OSS 120B#

cerebras-gpt-oss-120b selects GPT-OSS 120B served through Cerebras. It supports /v1/responses, including live text streaming after input permission. Generated tool calls remain buffered until assessed. Zaun currently caps this model at 16,384 output tokens. Input is $0.35 and output is $0.85 per million tokens. Cache reads are charged at the normal input rate. Discovery lists the model only when it is enabled for the deployment.

OpenAI GPT-6#

gpt-6-astra, gpt-6-sol, and gpt-6-luna route directly to OpenAI's Responses API using a Zaun-managed project credential, so function tools and reasoning.effort work together. Zaun rates per million tokens are respectively $10.00 / $50.10, $2.00 / $10.10, and $0.10 / $0.60 for input / output. Cached input is $1.00, $0.20, and $0.01. Cache writes use the provider's published 1.25x input rate. Zaun rejects requests whose conservative input budget could enter the provider's higher-priced long-context tier.

Only these three exact OpenAI model IDs are customer routes. Daybreak aliases and cybersecurity-specific models are not configured, discoverable, or routable.

Opus 5.5#

claude-opus-5-5 uses Bedrock's US inference profile. Zaun rates per million tokens are $4.40 input, $22.10 output, $0.22 cache reads, $5.50 five-minute cache writes, and $8.80 one-hour cache writes. The AWS model agreement offer for anthropic.claude-opus-5-5 was verified on September 25, 2026; the matching immutable price record is pinned in the deployment catalog. Existing scan charges are additional. The API exposes the model's 128,000-token output budget and provider defaults.

claude-opus-5-5 supports automatic tool selection (auto, the default) and disabling tools (none). Bedrock does not support forced named tools or required for this model. Zaun rejects those choices with HTTP 422 before scan or provider admission. Fable 5.1 has the same forced-selection restriction.

Nova Lite is not a completion model. It is absent from discovery, rejected by generation configuration, and absent from the completion price catalog. Document-extraction model settings are separate.