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POST
Create a chat completion (ZeroClick-authenticated)
This is the Chat completions endpoint behind ZeroClick, ZeroGPU’s agent-payment layer. Same request/response bodies and same model routing as /v1/chat/completions, except for retired model ids (below) — authentication, authorization, and metering differ.
  • Authentication — no x-api-key. A buying agent calls ZeroClick’s hosted pay URL; ZeroClick proxies the request and signs the raw request bytes with an HMAC in the zc-signature header. A request is authenticated only by a valid signature.
  • Authorization — a ZeroClick allowance check runs before any billable work. It fails open on a transient ZeroClick outage (the signature has already verified), but never for a missing or invalid signature.
  • Retired model ids — deepseek-v4-flash, glm-5.2 and gliner2-base-v1 are served and metered as their successors (deepseek-v4.1-flash, glm-5.3-flash, gliner2.5-base-v1); the response’s model is the successor. Send the current id.
  • Metering — actual token usage is settled with ZeroClick and reported via the zc-usage response header. Stripe metering is bypassed; ZeroClick is the sole biller.
Response JSON shape depends on the model; handle errors the same way as API error codes.

Authorizations

zc-signature
string
header
required

HMAC signature minted by ZeroClick over the raw request bytes, of the form t=<unix-seconds>,kid=<key-id>,v1=<hex-hmac>. Verified by the @zeroclickai/sellers SDK against the seller's signing secret keyed by kid. A missing or invalid signature is rejected with 401 invalid_zeroclick_signature; this is never failed open.

Headers

zc-request-id
string

ZeroClick request id, echoed in logs for correlation. Set by ZeroClick when it proxies the request.

Example:

"zcreq_1"

zc-agent-id
string

Identifier of the buying agent. Used to partition logs/analytics by agent; becomes the synthesized caller identity.

Example:

"agt_1"

Body

application/json
model
enum<string>
required

Model id; routes the request via model metadata. Kebab-cased into a ZeroClick service slug for metering. The same models are served on /zeroclick/v1/chat/completions and /zeroclick/v1/responses; embedding, moderation and audio models are routable only on their own endpoints. A retired id (deepseek-v4-flash, glm-5.2, gliner2-base-v1) is still accepted, and is served and metered as its successor.

Available options:
LFM2.5-1.2B-Instruct,
LFM2.5-1.2B-Thinking,
qwen3.6-35b-a3b,
qwen3-30b-a3b-fp8,
deepseek-v4.1-flash,
glm-5.3-flash,
gpt-4.1-mini,
gpt-5.4-nano,
gpt-5.6-luna,
gpt-oss-120b,
llama-3.1-8b-instruct-fast,
llama-3.2-3b-instruct-fast,
zlm-v1-iab-classify-edge,
zlm-v2-iab-classify-edge-enriched,
zlm-v1-iab-domain-classifier,
zlm-v1-signal-extract,
deberta-v3-small,
gliner2.5-base-v1,
gliner2.5-multi-v1,
gliner2.5-decide-v1,
gliner-multi-pii-v1
Example:

"LFM2.5-1.2B-Instruct"

messages
object[]
required
Minimum array length: 1
categories
string[]

Candidate labels for text-classification models. May also be supplied via a system-role message.

multilingual
boolean

Forwarded to the IAB cloud inference API only when the resolved model supports it.

metadata
object

Task-specific options. For GLiNER models this carries usecase, schema, labels, threshold, mask, and replacement_char. For moderation, threshold; for signal-extract, max_keywords.

Response

OpenAI Chat Completions response. Includes the zc-usage header settling actual usage with ZeroClick.

OpenAI Chat Completions response. For classification models, choices[0].message.content is a JSON-stringified classification result.

id
string
object
string
Allowed value: "chat.completion"
created
integer
model
string
choices
object[]
usage
object