xAI (Grok)¶

An OpenAI-compatible dialect whose distinctive value is reported cost: xAI reports the exact amount billed on every response, and its model listing carries real prices and context windows.

streaming structured output tool calls reasoning discovery (pricing + context)

Setup¶

import anyinfer as ai

client = ai.Client(
    [
        ai.ProviderSettings.of("xai", api_key="env://XAI_API_KEY"),
    ]
)

result = client.generate(prompt, target="xai:grok-4.5")

grok: is accepted as an alias.

Exact Cost¶

Most providers report token counts and leave the arithmetic to a price table. xAI returns cost_in_usd_ticks: the amount actually billed, including server-side tool fees and tiered pricing, and AnyInfer adopts it directly for cost accounting:

result = client.generate(prompt, target="xai:grok-4.5")
print(result.usage.cost_usd)  # what you were charged, not an estimate

That matters here because several of xAI's billing rules can't be reproduced from per-token rates: prompts of 200k tokens or more bill every token at the higher tier, web search costs $5 per 1,000 calls, and code execution costs $5 per 1,000 invocations.

Discovery¶

The language-models listing reports context windows and per-token prices, so capabilities arrive with discovered provenance rather than cataloged estimates:

for model in client.models("xai"):
    caps = model.capabilities
    if caps and caps.pricing:
        print(model.id, caps.pricing.value.input_per_1m, caps.pricing.provenance)

If that endpoint is unavailable, discovery degrades to the plain model listing (ids only) rather than failing.

Reasoning¶

result = client.generate(prompt, target="xai:grok-4.5", reasoning="medium")

minimal clamps to low: only some Grok models accept none, and silently disabling reasoning on a reasoning model would change the answer more than was asked for. Pass provider_options={"xai": {"reasoning_effort": "none"}} to disable it deliberately on a model that supports it. The grok-4.20 generation ships as separate -reasoning and -non-reasoning model ids instead of taking the parameter.

The Anthropic-Compatible Endpoint¶

xAI also exposes a Messages endpoint at https://api.x.ai, which the Anthropic adapter serves through a base-URL override; see pointing that adapter elsewhere. Use the native xai: provider unless Messages-dialect behavior is needed; the reported cost and discovered pricing above are only wired there.

Wire Contract¶

For the exact request/response fields this adapter depends on, see contracts/xai.md.