On-demand API

Make your first OpenAI-compatible Confidential AI request through Phala, then confirm it was served through an attested gateway.

Overview

On-demand Confidential AI API provides an OpenAI-compatible interface for confidential inference. Requests go through Phala’s ACI gateway at https://inference.phala.com/v1. The gateway runs in a TEE, publishes an attestation report, and signs a per-response receipt that you can verify.

For dedicated GPU resources with hourly pricing, see Dedicated Models. Both options use the same API surface; billing and resource allocation are the main differences.

Prerequisites

Before you begin, ensure you have enough funds to get the API key. You need at least $5 in your account. Go to Dashboard and click Deposit to add funds.

Navigate to Dashboard → Confidential AI API and click Enable. Then create your first API key and click the key to copy.

Once you get the API Key, you can start making requests to the Confidential AI API.

Make Your First Request

Replace <API_KEY> with your actual API key. The examples below use phala/qwen3.5-27b; use List Models to choose a model for your workload.

Python

# Install OpenAI SDK: `pip3 install openai`

from openai import OpenAI

client = OpenAI(
    api_key="<API_KEY>",
    base_url="https://inference.phala.com/v1",
)

response = client.chat.completions.create(
    model="phala/qwen3.5-27b",
    messages=[
        {"role": "system", "content": "You are a helpful assistant"},
        {"role": "user", "content": "What is your model name?"},
    ],
)

print(response.choices[0].message.content)

The response is a standard OpenAI chat completion. In raw HTTP responses, Phala also returns verification headers:

Header	Meaning
x-receipt-id	Receipt id for this response. Use it with GET /v1/aci/receipts/{id}.
x-aci-identity	Attested gateway workload identity.
x-aci-keyset-digest	Digest of the gateway keyset used for receipt verification.

Confirm the Response Was Attested

Fetch the receipt with the x-receipt-id header:

curl -s "https://inference.phala.com/v1/aci/receipts/$RECEIPT_ID" \
  -H "Authorization: Bearer <API_KEY>" | \
  jq '.event_log[] | select(.type=="upstream.verified") | {provider, result, required, session_id}'

For a confidential response, result is verified and required is true. To verify the gateway identity and receipt signature end to end, follow Verify a Response.

Available Models

The live catalog is authoritative; query it before hardcoding model IDs:

curl https://inference.phala.com/v1/models \
  -H "Authorization: Bearer <API_KEY>"

Pricing and availability can change; use the API response for production routing.

Phala Models

Model ID	Context	Modality	Pricing (input/output per 1M tokens)
phala/qwen3.5-27b	262K	Text	$0.30 /$2.40
phala/qwen3-vl-30b-a3b-instruct	128K	Vision + Text	$0.20 /$0.70
qwen/qwen3-embedding-8b	32K	Embeddings	$0.01 /$0
phala/gemma-3-27b-it	53K	Vision + Text	$0.11 /$0.40
phala/glm-4.7-flash	202K	Text	$0.10 /$0.43
phala/gpt-oss-20b	131K	Text	$0.04 /$0.15
phala/qwen-2.5-7b-instruct	32K	Text	$0.04 /$0.10
phala/qwen2.5-vl-72b-instruct	128K	Vision + Text	$0.40 /$1.20
phala/uncensored-24b	32K	Text	$0.20 /$0.90
sentence-transformers/all-minilm-l6-v2	512	Embeddings	$0.005 /$0

phala/qwen2.5-vl-72b-instruct is a legacy alias that may route to phala/qwen3-vl-30b-a3b-instruct. Prefer the canonical ID returned by /v1/models.

TEE provider presence and confidential serving are not identical for every provider and model. Use is_tee from /v1/models to find models that can be served confidentially, then verify the actual response with its x-receipt-id.

Confidential inference and zero data retention are separate properties. is_tee constrains who can read memory during execution. zdr constrains whether the upstream stores prompt or completion content after serving. Use GET /v1/models?zdr=true and provider: {"zdr": true} when retention is part of your policy.

Verify Your AI is Running Securely

Before trusting receipts, fetch a fresh Attestation Report. Then fetch the Receipt for a response and verify that its workload_id and workload_keyset_digest match the report.

The legacy Signature endpoint remains available for older clients, but new integrations should use GET /v1/aci/receipts/{id}.

Next Steps

Use the API reference and feature guides for the next step:

• Chat Completions documents the core request and response shape.
• List Models shows how to discover models programmatically.
• Get Receipt documents the canonical per-response proof.
• Embeddings covers embedding model calls.
• Tool Calling helps you call tools from your AI models.
• Images and Vision helps you use image-capable models.
• Structured Output helps you get JSON responses.
• Streaming helps you consume streaming responses.
• Zero Data Retention helps you route requests only to serving routes that do not retain prompt or completion content.
• Playground helps you test models in a private environment.