Apply API

POST

chat

completions

Create a chat completion

curl --request POST \
  --url https://api.morphllm.com/v1/chat/completions \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data @- <<EOF
{
  "model": "morph-v3-fast",
  "messages": [
    {
      "role": "user",
      "content": "<instruction>I will add error handling</instruction>\n<code>function divide(a, b) {\n  return a / b;\n}</code>\n<update>function divide(a, b) {\n  if (b === 0) throw new Error('Division by zero');\n  return a / b;\n}</update>"
    }
  ],
  "stream": false,
  "max_tokens": 150,
  "temperature": 0
}
EOF

import requests

url = "https://api.morphllm.com/v1/chat/completions"

payload = {
    "model": "morph-v3-fast",
    "messages": [
        {
            "role": "user",
            "content": "<instruction>I will add error handling</instruction>
<code>function divide(a, b) {
  return a / b;
}</code>
<update>function divide(a, b) {
  if (b === 0) throw new Error('Division by zero');
  return a / b;
}</update>"
        }
    ],
    "stream": False,
    "max_tokens": 150,
    "temperature": 0
}
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    model: 'morph-v3-fast',
    messages: [
      {
        role: 'user',
        content: '<instruction>I will add error handling</instruction>\n<code>function divide(a, b) {\n  return a / b;\n}</code>\n<update>function divide(a, b) {\n  if (b === 0) throw new Error(\'Division by zero\');\n  return a / b;\n}</update>'
      }
    ],
    stream: false,
    max_tokens: 150,
    temperature: 0
  })
};

fetch('https://api.morphllm.com/v1/chat/completions', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.morphllm.com/v1/chat/completions",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'model' => 'morph-v3-fast',
    'messages' => [
        [
                'role' => 'user',
                'content' => '<instruction>I will add error handling</instruction>
<code>function divide(a, b) {
  return a / b;
}</code>
<update>function divide(a, b) {
  if (b === 0) throw new Error(\'Division by zero\');
  return a / b;
}</update>'
        ]
    ],
    'stream' => false,
    'max_tokens' => 150,
    'temperature' => 0
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>",
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://api.morphllm.com/v1/chat/completions"

	payload := strings.NewReader("{\n  \"model\": \"morph-v3-fast\",\n  \"messages\": [\n    {\n      \"role\": \"user\",\n      \"content\": \"<instruction>I will add error handling</instruction>\\n<code>function divide(a, b) {\\n  return a / b;\\n}</code>\\n<update>function divide(a, b) {\\n  if (b === 0) throw new Error('Division by zero');\\n  return a / b;\\n}</update>\"\n    }\n  ],\n  \"stream\": false,\n  \"max_tokens\": 150,\n  \"temperature\": 0\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Authorization", "Bearer <token>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://api.morphllm.com/v1/chat/completions")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"model\": \"morph-v3-fast\",\n  \"messages\": [\n    {\n      \"role\": \"user\",\n      \"content\": \"<instruction>I will add error handling</instruction>\\n<code>function divide(a, b) {\\n  return a / b;\\n}</code>\\n<update>function divide(a, b) {\\n  if (b === 0) throw new Error('Division by zero');\\n  return a / b;\\n}</update>\"\n    }\n  ],\n  \"stream\": false,\n  \"max_tokens\": 150,\n  \"temperature\": 0\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.morphllm.com/v1/chat/completions")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"model\": \"morph-v3-fast\",\n  \"messages\": [\n    {\n      \"role\": \"user\",\n      \"content\": \"<instruction>I will add error handling</instruction>\\n<code>function divide(a, b) {\\n  return a / b;\\n}</code>\\n<update>function divide(a, b) {\\n  if (b === 0) throw new Error('Division by zero');\\n  return a / b;\\n}</update>\"\n    }\n  ],\n  \"stream\": false,\n  \"max_tokens\": 150,\n  \"temperature\": 0\n}"

response = http.request(request)
puts response.read_body

{
  "id": "chatcmpl-123",
  "object": "chat.completion",
  "created": 1677652288,
  "choices": [
    {
      "index": 0,
      "message": {
        "role": "assistant",
        "content": "\ndef calculate_total(items):\n    total = 0\n    for item in items:\n        total += item.price\n    return total * 1.1  # Add 10% tax\n"
      },
      "finish_reason": "stop"
    }
  ],
  "usage": {
    "prompt_tokens": 25,
    "completion_tokens": 32,
    "total_tokens": 57
  }
}

{
  "error": {
    "code": "invalid_request_error",
    "message": "The request body is missing the `model` field."
  }
}

{
  "error": {
    "code": "unauthorized",
    "message": "Invalid API key provided."
  }
}

{
  "error": {
    "code": "rate_limited",
    "message": "Too many requests. Retry in 12 seconds."
  }
}

{
  "error": {
    "code": "internal_error",
    "message": "Something went wrong on our side."
  }
}

Overview

The Apply API enables lightning-fast code editing at 10,500+ tokens/second with 98% accuracy. This OpenAI-compatible endpoint intelligently merges code changes while preserving structure and formatting.

Models

Choose the model that best fits your use case:

Message Format

The Apply API uses a structured XML format within the message content:

<instruction>Brief description of what you're changing</instruction>
<code>Original code content</code>
<update>Code snippet showing only the changes with // ... existing code ... markers</update>

Format Guidelines

<instruction>: Optional but recommended. Use first-person, clear descriptions
<code>: The complete original code that needs modification
<update>: Show only what changes, using // ... existing code ... for unchanged sections

Usage Examples

import OpenAI from "openai";

const openai = new OpenAI({
  apiKey: "YOUR_API_KEY",
  baseURL: "https://api.morphllm.com/v1",
});

const instruction = "I will add error handling to prevent division by zero";
const originalCode = "function divide(a, b) {\n  return a / b;\n}";
const codeEdit = "function divide(a, b) {\n  if (b === 0) {\n    throw new Error('Cannot divide by zero');\n  }\n  return a / b;\n}";

const response = await openai.chat.completions.create({
  model: "morph-v3-fast",
  messages: [
    {
      role: "user",
      content: `<instruction>${instruction}</instruction>\n<code>${originalCode}</code>\n<update>${codeEdit}</update>`,
    },
  ],
});

const mergedCode = response.choices[0].message.content;

import os
from openai import OpenAI

client = OpenAI(
    api_key="YOUR_API_KEY",
    base_url="https://api.morphllm.com/v1"
)

instruction = "I will add error handling to prevent division by zero"
original_code = "function divide(a, b) {\n  return a / b;\n}"
code_edit = "function divide(a, b) {\n  if (b === 0) {\n    throw new Error('Cannot divide by zero');\n  }\n  return a / b;\n}"

response = client.chat.completions.create(
    model="morph-v3-fast",
    messages=[
        {
            "role": "user",
            "content": f"<instruction>{instruction}</instruction>\n<code>{original_code}</code>\n<update>{code_edit}</update>"
        }
    ]
)

merged_code = response.choices[0].message.content

curl -X POST "https://api.morphllm.com/v1/chat/completions" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "morph-v3-fast",
    "messages": [
      {
        "role": "user",
        "content": "<instruction>I will add error handling to prevent division by zero</instruction>\n<code>function divide(a, b) {\n  return a / b;\n}</code>\n<update>function divide(a, b) {\n  if (b === 0) {\n    throw new Error(\"Cannot divide by zero\");\n  }\n  return a / b;\n}</update>"
      }
    ]
  }'

Error Codes

edit_file Tool Guide

Build AI agent tools with Morph Apply

More Examples

See more implementation patterns

Authorizations

Authorization

string

header

required

Morph API key, passed as Authorization: Bearer sk-.... Create keys at https://www.morphllm.com/dashboard/api-keys.

Body

application/json

Chat completion request for Apply or Warp Grep (OpenAI-compatible)

Morph Apply
Warp Grep

Either a Morph Apply request or a Warp Grep request, discriminated by model.

model

enum<string>

default:morph-v3-fast

required

ID of the Apply model to use, or auto to let the router choose

Available options:

morph-v3-fast,

morph-v3-large,

auto

Example:

"morph-v3-fast"

messages

object[]

required

Array containing a single user message with structured content using instruction-guided format

Show child attributes

Example:

[
  {
    "role": "user",
    "content": "<instruction>I will add error handling</instruction>\n<code>function divide(a, b) {\n  return a / b;\n}</code>\n<update>function divide(a, b) {\n  if (b === 0) throw new Error('Division by zero');\n  return a / b;\n}</update>"
  }
]

stream

boolean

default:false

Enable streaming response. When true the response is a text/event-stream of OpenAI-style chat.completion.chunk deltas terminated by data: [DONE].

Example:

false

max_tokens

integer

Maximum number of tokens the Apply model may generate

Example:

150

temperature

number

default:0

Sampling temperature for the Apply request (0.0 for deterministic output)

Example:

0

Response

Chat completion response

Completion returned by a Morph chat model.

string

required

Unique identifier for the completion

Example:

"chatcmpl-123"

object

string

required

Always chat.completion

Example:

"chat.completion"

created

integer

required

Unix timestamp of when the completion was created

Example:

1677652288

choices

object[]

required

List of completion choices

Show child attributes

Example:

[
  {
    "index": 0,
    "message": {
      "role": "assistant",
      "content": "\ndef calculate_total(items):\n    total = 0\n    for item in items:\n        total += item.price\n    return total * 1.1  # Add 10% tax\n"
    },
    "finish_reason": "stop"
  }
]

usage

object

required

Usage statistics for the completion request

Show child attributes

Example:

{
  "prompt_tokens": 25,
  "completion_tokens": 32,
  "total_tokens": 57
}

Create a chat completion

curl --request POST \
  --url https://api.morphllm.com/v1/chat/completions \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data @- <<EOF
{
  "model": "morph-v3-fast",
  "messages": [
    {
      "role": "user",
      "content": "<instruction>I will add error handling</instruction>\n<code>function divide(a, b) {\n  return a / b;\n}</code>\n<update>function divide(a, b) {\n  if (b === 0) throw new Error('Division by zero');\n  return a / b;\n}</update>"
    }
  ],
  "stream": false,
  "max_tokens": 150,
  "temperature": 0
}
EOF

import requests

url = "https://api.morphllm.com/v1/chat/completions"

payload = {
    "model": "morph-v3-fast",
    "messages": [
        {
            "role": "user",
            "content": "<instruction>I will add error handling</instruction>
<code>function divide(a, b) {
  return a / b;
}</code>
<update>function divide(a, b) {
  if (b === 0) throw new Error('Division by zero');
  return a / b;
}</update>"
        }
    ],
    "stream": False,
    "max_tokens": 150,
    "temperature": 0
}
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    model: 'morph-v3-fast',
    messages: [
      {
        role: 'user',
        content: '<instruction>I will add error handling</instruction>\n<code>function divide(a, b) {\n  return a / b;\n}</code>\n<update>function divide(a, b) {\n  if (b === 0) throw new Error(\'Division by zero\');\n  return a / b;\n}</update>'
      }
    ],
    stream: false,
    max_tokens: 150,
    temperature: 0
  })
};

fetch('https://api.morphllm.com/v1/chat/completions', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.morphllm.com/v1/chat/completions",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'model' => 'morph-v3-fast',
    'messages' => [
        [
                'role' => 'user',
                'content' => '<instruction>I will add error handling</instruction>
<code>function divide(a, b) {
  return a / b;
}</code>
<update>function divide(a, b) {
  if (b === 0) throw new Error(\'Division by zero\');
  return a / b;
}</update>'
        ]
    ],
    'stream' => false,
    'max_tokens' => 150,
    'temperature' => 0
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>",
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://api.morphllm.com/v1/chat/completions"

	payload := strings.NewReader("{\n  \"model\": \"morph-v3-fast\",\n  \"messages\": [\n    {\n      \"role\": \"user\",\n      \"content\": \"<instruction>I will add error handling</instruction>\\n<code>function divide(a, b) {\\n  return a / b;\\n}</code>\\n<update>function divide(a, b) {\\n  if (b === 0) throw new Error('Division by zero');\\n  return a / b;\\n}</update>\"\n    }\n  ],\n  \"stream\": false,\n  \"max_tokens\": 150,\n  \"temperature\": 0\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Authorization", "Bearer <token>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://api.morphllm.com/v1/chat/completions")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"model\": \"morph-v3-fast\",\n  \"messages\": [\n    {\n      \"role\": \"user\",\n      \"content\": \"<instruction>I will add error handling</instruction>\\n<code>function divide(a, b) {\\n  return a / b;\\n}</code>\\n<update>function divide(a, b) {\\n  if (b === 0) throw new Error('Division by zero');\\n  return a / b;\\n}</update>\"\n    }\n  ],\n  \"stream\": false,\n  \"max_tokens\": 150,\n  \"temperature\": 0\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.morphllm.com/v1/chat/completions")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"model\": \"morph-v3-fast\",\n  \"messages\": [\n    {\n      \"role\": \"user\",\n      \"content\": \"<instruction>I will add error handling</instruction>\\n<code>function divide(a, b) {\\n  return a / b;\\n}</code>\\n<update>function divide(a, b) {\\n  if (b === 0) throw new Error('Division by zero');\\n  return a / b;\\n}</update>\"\n    }\n  ],\n  \"stream\": false,\n  \"max_tokens\": 150,\n  \"temperature\": 0\n}"

response = http.request(request)
puts response.read_body

{
  "id": "chatcmpl-123",
  "object": "chat.completion",
  "created": 1677652288,
  "choices": [
    {
      "index": 0,
      "message": {
        "role": "assistant",
        "content": "\ndef calculate_total(items):\n    total = 0\n    for item in items:\n        total += item.price\n    return total * 1.1  # Add 10% tax\n"
      },
      "finish_reason": "stop"
    }
  ],
  "usage": {
    "prompt_tokens": 25,
    "completion_tokens": 32,
    "total_tokens": 57
  }
}

{
  "error": {
    "code": "invalid_request_error",
    "message": "The request body is missing the `model` field."
  }
}

{
  "error": {
    "code": "unauthorized",
    "message": "Invalid API key provided."
  }
}

{
  "error": {
    "code": "rate_limited",
    "message": "Too many requests. Retry in 12 seconds."
  }
}

{
  "error": {
    "code": "internal_error",
    "message": "Something went wrong on our side."
  }
}

Get Started

Models

API Reference

Integrations

Overview

Models

Message Format

Format Guidelines

Usage Examples

Error Codes

edit_file Tool Guide

More Examples

Authorizations

Body

Response

​Overview

​Models

​Message Format

​Format Guidelines

​Usage Examples

​Error Codes

edit_file Tool Guide

More Examples

Authorizations

Body

Response

Overview

Models

Message Format

Format Guidelines

Usage Examples

Error Codes