Completion

Overview

The /api/completion endpoint provides intelligent inline writing assistance for text completions, transformations, grammar fixes, and style adjustments. It’s designed for seamless integration into text editors and input fields, offering personalized suggestions based on user memory.

This endpoint returns Server-Sent Events (SSE) for streaming completions.

Endpoint

POST /api/completion

Authentication

Requires authentication via cookies or Authorization header. Alternatively, accepts userId in request body for internal calls.

Returns 401 Unauthorized if authentication fails.

Request Body

UIMessage[]

required

Array of messages containing the text to complete or transform. Typically contains a single user message with the input text.

interface UIMessage {
  id: string
  role: 'user' | 'assistant' | 'system'
  content: string
  parts?: any[]
}

ActionType

required

The type of completion or transformation to perform.

Show Available actions

fix-grammar: Correct grammar and spelling errors
shorten: Make text more concise
expand: Add detail and expand text
professional-tone: Convert to professional tone
casual-tone: Convert to casual tone
friendly-tone: Convert to friendly tone
email-writer: Format as professional email
custom: Use custom prompt
chat: General chat completion
Any custom string for specialized actions

string

Custom instructions to prepend to the system prompt. Used when action is "custom" or when you want to provide additional context.

{
  "action": "custom",
  "customPrompt": "Translate this to Spanish and make it formal"
}

string

User identifier. Used as fallback if authentication via cookies/headers is not available.

Response

Returns a Server-Sent Events (SSE) stream with JSON payloads:

string

Event type (text, tool-call, tool-result, reasoning, finish).

string

Text chunk or event content. For completions, this contains the transformed/completed text.

string

Unique message or chunk ID.

Available Tools

The completion endpoint has access to memory tools for personalization:

Show searchMemory

Automatically called before every completion to personalize the response based on:

User’s writing style preferences (formal/casual, verbose/concise)
Email signatures and tone preferences
Technical terminology and tech stack
Previous corrections and feedback

Parameters:

query (string): Search query extracted from context
userId (string): User identifier
limit (number, optional): Maximum results (default: 5)

Show addMemory

Stores new insights about the user’s preferences when they make corrections or reveal new information.Parameters:

messages (array): Conversation messages containing user preferences
userId (string): User identifier

Show tavilySearchTool

Web search for current information when needed for content generation.Parameters:

query (string): Search query

Behavior

The completion endpoint is designed to:

Return only the final transformed text (no explanations or preambles)
Always search memory first to personalize the output
Match the user’s preferred writing style and tone
Preserve formatting and capitalization preferences
Store corrections and feedback for future improvements

Example Request

const response = await fetch('/api/completion', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    messages: [
      {
        id: '1',
        role: 'user',
        content: 'hey can u send me the report tmrw'
      }
    ],
    action: 'professional-tone'
  })
});

// Handle SSE stream
const reader = response.body.getReader();
const decoder = new TextDecoder();
let result = '';

while (true) {
  const { done, value } = await reader.read();
  if (done) break;
  
  const chunk = decoder.decode(value);
  const lines = chunk.split('\n');
  
  for (const line of lines) {
    if (line.startsWith('data: ')) {
      const data = JSON.parse(line.slice(6));
      if (data.type === 'text') {
        result += data.content;
      }
    }
  }
}

console.log(result); // "Hello, could you please send me the report tomorrow?"

Example with Custom Prompt

const response = await fetch('/api/completion', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    messages: [
      {
        id: '1',
        role: 'user',
        content: 'function add(a, b) { return a + b }'
      }
    ],
    action: 'custom',
    customPrompt: 'Add TypeScript types and JSDoc comments'
  })
});

Example Response Stream

data: {"type":"reasoning","content":"Searching user preferences..."}

data: {"type":"text","content":"Hello"}

data: {"type":"text","content":","}

data: {"type":"text","content":" could"}

data: {"type":"text","content":" you"}

data: {"type":"text","content":" please"}

data: {"type":"text","content":" send"}

data: {"type":"text","content":" me"}

data: {"type":"text","content":" the"}

data: {"type":"text","content":" report"}

data: {"type":"text","content":" tomorrow"}

data: {"type":"text","content":"?"}

data: {"type":"finish"}

Error Responses

error

Returned when messages parameter is missing or invalid.

"Missing messages"

error

Returned when authentication fails.

"Unauthorized"

Use Cases

Grammar Correction: Fix spelling and grammar errors inline
Tone Adjustment: Convert between professional, casual, and friendly tones
Email Writing: Transform quick notes into polished emails
Text Expansion: Add detail and context to brief text
Text Condensing: Shorten verbose text while preserving meaning
Code Completion: Complete or format code snippets
Translation: Translate and adapt text to different languages and styles
Creative Writing: Continue stories or creative content

Best Practices

Let the system search memory automatically - it will personalize based on past interactions
Use action types for common transformations instead of custom prompts when possible
For email writing, the system will automatically include the user’s signature if stored in memory
The endpoint learns from corrections, so user feedback improves future completions

Memory API

Backend API

Electron IPC

Overview

Endpoint

Authentication

Request Body

Response

Available Tools

Behavior

Example Request

Example with Custom Prompt

Example Response Stream

Error Responses

Use Cases

Best Practices

​Overview

​Endpoint

​Authentication

​Request Body

​Response

​Available Tools

​Behavior

​Example Request

​Example with Custom Prompt

​Example Response Stream

​Error Responses

​Use Cases

​Best Practices

Overview

Endpoint

Authentication

Request Body

Response

Available Tools

Behavior

Example Request

Example with Custom Prompt

Example Response Stream

Error Responses

Use Cases

Best Practices