Building Inferencesh Apps

CLI Installation

curl -fsSL https://cli.inference.sh | sh

infsh update   # Update CLI
infsh login    # Authenticate
infsh me       # Check current user

Quick Start

Scaffold new apps with infsh app init (see Rules above). It generates the correct project structure, inf.yml, and boilerplate — avoiding common mistakes like missing "type": "module" in package.json or incorrect kernel names.

infsh app init my-app              # Create app (interactive)
infsh app init my-app --lang node  # Create Node.js app

Development Workflow (mandatory)

Every app MUST go through this full cycle. Do not skip steps.

1. Scaffold

infsh app init my-app

2. Implement

Write inference.py (or inference.js), inf.yml, and requirements.txt (or package.json).

3. Test Locally

cd my-app                          # ALWAYS cd into app dir first
infsh app test --save-example      # Generate sample input from schema
infsh app test                     # Run with input.json
infsh app test --input '{"prompt": "hello"}'  # Or inline JSON

4. Deploy

cd my-app                          # cd again — cwd doesn't persist
infsh app deploy --dry-run         # Validate first
infsh app deploy                   # Deploy for real

5. Cloud Test & Verify

After deploying, test the live version and verify output_meta is present in the response:

infsh app run user/app --json --input '{"prompt": "hello"}'

Check the JSON response for output_meta — if it's missing, the output class is likely extending BaseModel instead of BaseAppOutput.

# Other useful commands
infsh app run user/app --input input.json
infsh app sample user/app
infsh app sample user/app --save input.json

App Structure

Python

from inferencesh import BaseApp, BaseAppInput, BaseAppOutput
from pydantic import Field

class AppSetup(BaseAppInput):
    """Setup parameters — triggers re-init when changed"""
    model_id: str = Field(default="gpt2", description="Model to load")

class AppInput(BaseAppInput):
    prompt: str = Field(description="Input prompt")

class AppOutput(BaseAppOutput):
    result: str = Field(description="Output result")

class App(BaseApp):
    async def setup(self, config: AppSetup):
        """Runs once when worker starts or config changes"""
        self.model = load_model(config.model_id)

    async def run(self, input_data: AppInput) -> AppOutput:
        """Default function — runs for each request"""
        self.logger.info(f"Processing prompt: {input_data.prompt[:50]}")
        result = self.model.generate(input_data.prompt)
        self.logger.info("Generation complete")
        return AppOutput(result=result)

    async def unload(self):
        """Cleanup on shutdown"""
        pass

    async def on_cancel(self):
        """Called when user cancels — for long-running tasks"""
        return True

Node.js

import { z } from "zod";

export const AppSetup = z.object({
  modelId: z.string().default("gpt2").describe("Model to load"),
});

export const RunInput = z.object({
  prompt: z.string().describe("Input prompt"),
});

export const RunOutput = z.object({
  result: z.string().describe("Output result"),
});

export class App {
  async setup(config) {
    /** Runs once when worker starts or config changes */
    this.model = loadModel(config.modelId);
  }

  async run(inputData) {
    /** Default function — runs for each request */
    return { result: "done" };
  }

  async unload() {
    /** Cleanup on shutdown */
  }

  async onCancel() {
    /** Called when user cancels — for long-running tasks */
    return true;
  }
}

Multi-Function Apps

Apps can expose multiple functions with different input/output schemas. Functions are auto-discovered.

Python: Add methods with type-hinted Pydantic input/output models. Node.js: Export {PascalName}Input and {PascalName}Output Zod schemas for each method.

Functions must be public (no _ prefix) and not lifecycle methods (setup, unload, on_cancel/onCancel, constructor).

Call via API with "function": "method_name" in the request body. Set default_function in inf.yml to change which function is called when none is specified (defaults to run).

API-Wrapper App Template (Python)

Most CPU-only apps that wrap external APIs follow this pattern. Use this as a starting point:

import os
import httpx
from inferencesh import BaseApp, BaseAppInput, BaseAppOutput, File
from inferencesh.models.usage import OutputMeta, ImageMeta  # or TextMeta, AudioMeta, etc.
from pydantic import Field

class AppInput(BaseAppInput):
    prompt: str = Field(description="Input prompt")

class AppOutput(BaseAppOutput):  # NOT BaseModel — output_meta requires this
    image: File = Field(description="Generated image")

class App(BaseApp):
    async def setup(self, config):
        self.api_key = os.environ["API_KEY"]
        self.client = httpx.AsyncClient(timeout=120)

    async def run(self, input_data: AppInput) -> AppOutput:
        self.logger.info(f"Calling API with prompt: {input_data.prompt[:80]}")

        response = await self.client.post(
            "https://api.example.com/generate",
            headers={"Authorization": f"Bearer {self.api_key}"},
            json={"prompt": input_data.prompt},
        )
        response.raise_for_status()

        # Write output file
        output_path = "/tmp/output.png"
        with open(output_path, "wb") as f:
            f.write(response.content)

        # Read actual dimensions (don't hardcode!)
        from PIL import Image
        with Image.open(output_path) as img:
            width, height = img.size

        self.logger.info(f"Generated {width}x{height} image")

        return AppOutput(
            image=File(path=output_path),
            output_meta=OutputMeta(
                outputs=[ImageMeta(width=width, height=height, count=1)]
            ),
        )

    async def unload(self):
        await self.client.aclose()

Configuring Resources (inf.yml)

Project Structure

Python:

my-app/
├── inf.yml           # Configuration
├── inference.py      # App logic
├── requirements.txt  # Python packages (pip)
└── packages.txt      # System packages (apt) — optional

Node.js:

my-app/
├── inf.yml           # Configuration
├── src/
│   └── inference.js  # App logic
├── package.json      # Node.js packages (npm/pnpm)
└── packages.txt      # System packages (apt) — optional

inf.yml