Gemini 4 Carbon - Unifically

Gemini 4 Carbon is Google’s most capable Gemini 4 reasoning model, released to developers on November 10, 2026 and built for long agentic coding, finance, legal, and security work. It accepts text and image input with a 1M-token window shared by input and output, and returns up to 64K output tokens per response. Reasoning effort is tunable with reasoning_effort set to low, medium, or high. Thinking tokens are billed as output tokens. Long reasoning at high can take several minutes, so stream the response and set client timeouts with headroom. Try it in the browser: Gemini 4 Carbon API playground.

Model

google/gemini-4-carbon


Provider	Google
Name	Gemini 4 Carbon

Supported Endpoints

Chat Completions — POST /v1/chat/completions

Send LLM requests to https://direct-api.unifically.com, not https://api.unifically.com. The main host sits behind Cloudflare, and Cloudflare’s proxy timeout cuts most LLM requests short before the model has finished writing. When that happens you receive a truncated reply and are still charged for every token generated up to the cut-off. direct-api.unifically.com reaches the same API without the Cloudflare proxy, so long responses complete in full.

Example

curl -X POST https://direct-api.unifically.com/v1/chat/completions \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
    "model": "google/gemini-4-carbon",
    "reasoning_effort": "high",
    "stream": true,
    "messages": [
      {"role": "user", "content": "Review this module for security bugs and propose a patch for the worst one."}
    ]
  }'

Image Input

Send an image in an image_url content part alongside your text, either as a direct https link or inline as a base64 data URI.

curl -X POST https://direct-api.unifically.com/v1/chat/completions \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
    "model": "google/gemini-4-carbon",
    "messages": [
      {"role": "user", "content": [
        {"type": "text", "text": "Read every label in this diagram and explain how the parts connect."},
        {"type": "image_url", "image_url": {"url": "https://example.com/diagram.png"}}
      ]}
    ]
  }'


Accepted shape	`image_url` part with a direct https link or a `data:image/...;base64` URI
Links	Must point straight at the image file, with no redirect, up to 14 MB. A link that cannot be downloaded returns `400` with the reason
Billing	Counted as input tokens at the model’s input rate. The `usage.prompt_tokens` field shows the total

Volume discounts are available for almost all models. Reach out at contact@unifically.com to discuss custom pricing.

​Model

​Supported Endpoints

​Example

​Image Input

Model

Supported Endpoints

Example

Image Input