> ## Documentation Index
> Fetch the complete documentation index at: https://docs.zerogpu.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# LFM2.5-1.2B-Thinking

> Model details for LFM2.5-1.2B-Thinking.

> Liquid AI's LFM2.5-1.2B-Thinking is a compact reasoning model that works through a problem step by step before it answers. Built by Liquid AI, it generates an explicit chain-of-thought trace so for multi-step math, planning, data extraction, and agentic tool-calling, you get verifiable intermediate reasoning, not just a final guess. At 1.2B parameters it fits under a gigabyte and runs fast on CPU at the edge, rivaling models several times its size on reasoning benchmarks. Reach for a frontier model when the task is knowledge-heavy or code-intensive, and keep this one as the planning brain that decides and orchestrates. When the task needs reasoning, this is the model.

**References:** [Model docs](https://docs.liquid.ai/deployment/on-device/android/ai-agent-usage-guide#text-models) • [Terms](https://www.liquid.ai/terms-conditions) • [Privacy](https://www.liquid.ai/lfm-license)


## OpenAPI

````yaml api-reference/openapi/playgrounds/LFM2_5-1_2B-Thinking.openapi.json POST /responses
openapi: 3.1.0
info:
  title: LFM2.5-1.2B-Thinking playground
  version: '1.0'
  description: >-
    Interactive playground for **LFM2.5-1.2B-Thinking**.

    Model is always `LFM2.5-1.2B-Thinking` on this page (shown in the form, not
    editable).

    Use the **request example** selector to switch use cases (JSON, NER, PII,
    etc.).

    Authentication: `x-api-key` (required) and `x-project-id` (optional).
servers:
  - url: https://api.zerogpu.ai/v1
    description: Production
security:
  - ApiKey: []
paths:
  /responses:
    post:
      tags:
        - LFM2.5-1.2B-Thinking
      summary: 'LFM2.5-1.2B-Thinking: Responses'
      operationId: createResponse_LFM2_5-1_2B-Thinking
      parameters:
        - name: x-project-id
          in: header
          required: false
          schema:
            type: string
          description: >-
            Optional project identifier. Scopes the request to a specific
            project when provided.
      requestBody:
        required: true
        content:
          application/json:
            schema:
              allOf:
                - $ref: '#/components/schemas/CreateResponseRequest'
                - type: object
                  properties:
                    model:
                      type: string
                      const: LFM2.5-1.2B-Thinking
                      default: LFM2.5-1.2B-Thinking
                      example: LFM2.5-1.2B-Thinking
                      description: >-
                        Model identifier (fixed for this playground). Use
                        request examples to change use cases.
            examples:
              default:
                summary: Default
                value:
                  input: What is the capital of Japan
                  model: LFM2.5-1.2B-Thinking
      responses:
        '200':
          description: Success
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Response'
              examples:
                default:
                  summary: Default
                  value: >-
                    The capital of Japan is **Tokyo**.


                    **Reasoning:**

                    1. Japan's political, cultural, and economic center is
                    located in Tokyo.

                    2. Historically, Tokyo has served as Japan's...
        '400':
          description: Bad request
        '401':
          description: Unauthorized
        '403':
          description: Forbidden
        '420':
          description: Insufficient quota
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
        '500':
          description: Internal server error
components:
  schemas:
    CreateResponseRequest:
      type: object
      required:
        - model
        - input
      properties:
        model:
          type: string
          const: LFM2.5-1.2B-Thinking
          default: LFM2.5-1.2B-Thinking
          example: LFM2.5-1.2B-Thinking
          description: >-
            Model identifier (fixed for this playground). Use request examples
            to change use cases.
        input:
          type: string
          minLength: 1
          format: textarea
          maxLength: 131072
          description: Multi-line text or document content to send to the model.
        instructions:
          type: string
        metadata:
          type: object
          additionalProperties: true
    Response:
      type: object
      additionalProperties: true
    ErrorResponse:
      type: object
      additionalProperties: true
  securitySchemes:
    ApiKey:
      type: apiKey
      in: header
      name: x-api-key

````