api-generation.mdx

title	description	og:title
API Generation	Create the signature for your API	API Generation - Modus

Modus automatically creates an external API based on the endpoints defined in your app manifest. Modus generates the API signature based on the functions you export from your app.

Exporting functions

Modus uses the default conventions for each language.

Functions written in Go use starting capital letters to expose functions as public. Modus creates an external API for public functions from any file that belongs to the `main` package.

The functions below generate an API endpoint with the signature

type Query {
  classifyText(text: String!, threshold: Float!): String!
}

Since the classify function isn't capitalized, Modus doesn't include it in the generated GraphQL API.

package main

import (
  "errors"
  "fmt"
  "github.com/hypermodeinc/modus/sdk/go/models"
  "github.com/hypermodeinc/modus/sdk/go/models/experimental"
)

const modelName = "my-classifier"

// this function takes input text and a probability threshold, and returns the
// classification label determined by the model, if the confidence is above the
// threshold; otherwise, it returns an empty string

func ClassifyText(text string, threshold float32) (string, error) {
  predictions, err:= classify(text)
  if err != nil {
    return "", err
  }

  prediction := predictions[0]
  if prediction.Confidence < threshold {
    return "", nil
  }

  return prediction.Label, nil
}

func classify(texts ...string) ([]experimental.ClassifierResult, error) {
  model, err := models.GetModel[experimental.ClassificationModel](modelName)
  if err != nil {
    return nil, err
  }

  input, err := model.CreateInput(texts...)
  if err != nil {
    return nil, err
  }

  output, err := model.Invoke(input)
  if err != nil {
    return nil, err
  }

  if len(output.Predictions) != len(texts) {
    word := "prediction"
    if len(texts) > 1 {
      word += "s"
    }

    return nil, fmt.Errorf("expected %d %s, got %d", len(texts), word, len(output.Predictions))
  }

  return output.Predictions, nil
}

Functions written in AssemblyScript use ES module-style `import` and `export` statements. With the default package configuration, Modus creates an external API for functions exported form the `index.ts` file located in the `functions/assembly` folder of your project.

The functions below generate an API endpoint with the signature

type Query {
  classifyText(text: String!, threshold: Float!): String!
}

Since the classify function isn't exported from the module, Modus doesn't include it in the generated GraphQL API.

import { models } from "@hypermode/modus-sdk-as"
import {
  ClassificationModel,
  ClassifierResult,
} from "@hypermode/modus-sdk-as/models/experimental/classification"

const modelName: string = "my-classifier"

// this function takes input text and a probability threshold, and returns the
// classification label determined by the model, if the confidence is above the
// threshold; otherwise, it returns an empty string
export function classifyText(text: string, threshold: f32): string {
  const predictions = classify(text, threshold)

  const prediction = predictions[0]
  if (prediction.confidence < threshold) {
    return ""
  }

  return prediction.label
}

function classify(text: string, threshold: f32): ClassifierResult[] {
  const model = models.getModel<ClassificationModel>(modelName)
  const input = model.createInput([text])
  const output = model.invoke(input)

  return output.predictions
}