IntegrationsSet up

Set up your agent in a few minutes

Pick your tool, create a key and paste in the settings. If you write your own code, the API basics are further down.

01Your agent

Pick your tool

Using a tool that isn't listed? Any client that speaks one of the three protocols below works with the same settings.

Anthropic Messagesrecommended: auto

Create an API key
Sign up at modeless.ai and create a key in the console.

Point Claude Code at Modeless

Add these to your shell profile, then open a new terminal.

bash

export ANTHROPIC_BASE_URL="https://api.modeless.ai"
export ANTHROPIC_AUTH_TOKEN="<your-modeless-key>"
export ANTHROPIC_MODEL="auto"

✓
Check it works
Run claude and send one message. /status shows the Modeless base URL.
- · Routing survives context compaction: the session keeps its model.
- · Sub-agents get their own routing state, separate from the parent.

OpenAI Responsesrecommended: auto

Create an API key
Sign up at modeless.ai and create a key in the console.

Add a provider to ~/.codex/config.toml

toml

model = "auto"
model_provider = "modeless"

[model_providers.modeless]
name = "Modeless"
base_url = "https://api.modeless.ai/v1"
env_key = "MODELESS_API_KEY"
wire_api = "responses"

Export your key

bash

export MODELESS_API_KEY="<your-modeless-key>"

Check it works
Run codex and send one message. The header shows model auto.

OpenAI Chat Completionsrecommended: auto

Create an API key
Sign up at modeless.ai and create a key in the console.

Add Modeless to opencode.json

json

{
  "$schema": "https://opencode.ai/config.json",
  "provider": {
    "modeless": {
      "npm": "@ai-sdk/openai-compatible",
      "name": "Modeless",
      "options": {
        "baseURL": "https://api.modeless.ai/v1",
        "apiKey": "{env:MODELESS_API_KEY}"
      },
      "models": {
        "auto": { "name": "Auto" },
        "fusion": { "name": "Fusion" }
      }
    }
  },
  "model": "modeless/auto"
}

Check it works
Run opencode, pick modeless/auto with /models, and send one message.

OpenAI Chat Completionsrecommended: auto

Create an API key
Sign up at modeless.ai and create a key in the console.

Open Cline settings

Set API Provider to OpenAI Compatible, then fill in:

text

Base URL   https://api.modeless.ai/v1
API Key    <your-modeless-key>
Model ID   auto

Check it works
Start a new task. The task header shows model auto.

OpenAI Chat Completionsrecommended: fusion

Create an API key
Sign up at modeless.ai and create a key in the console.

Settings → Models

Enable Override OpenAI Base URL, paste your key, and add custom models:

text

OpenAI Base URL   https://api.modeless.ai/v1
OpenAI API Key    <your-modeless-key>
Custom models     auto, fusion

Check it works
Select auto in the chat model picker and send one message.

02API basics

For code you write yourself

Modeless accepts three API formats unchanged. Change the base URL and the model name, and your existing client keeps working.

Base URL

https://api.modeless.ai

Add /v1 for OpenAI clients. Anthropic clients take the bare host.

Authentication

Your Modeless key, as Authorization: Bearer or x-api-key, the way your SDK already sends it.

Endpoints

POST /v1/chat/completions: OpenAI Chat Completions
POST /v1/messages: Anthropic Messages
POST /v1/responses: OpenAI Responses

JSON or SSE streaming on all three.

Models

auto: picks the model as the session goes
fusion: panel plus aggregator

Sessions

Auto treats each conversation as one session. If you build your own agent, send X-Session-ID with a stable id per task. Without it, Auto recognizes a session by its first user message. Claude Code's own session header is read automatically.

Errors

Errors come back in the format of the protocol you called, so your SDK's error handling works unchanged. With Auto, a request too large for every model's context window returns 400.

python

from openai import OpenAI

client = OpenAI(base_url="https://api.modeless.ai/v1", api_key="<your-modeless-key>")

stream = client.chat.completions.create(
    model="auto",
    messages=[{"role": "user", "content": "Write a migration for..."}],
    stream=True,
    extra_headers={"X-Session-ID": "task-1842"},
)
for chunk in stream:
    print(chunk.choices[0].delta.content or "", end="")

from anthropic import Anthropic

client = Anthropic(base_url="https://api.modeless.ai", api_key="<your-modeless-key>")

msg = client.messages.create(
    model="fusion",
    max_tokens=4096,
    messages=[{"role": "user", "content": "Review this design: ..."}],
)
print(msg.content[0].text)

curl https://api.modeless.ai/v1/responses \
  -H "Authorization: Bearer $MODELESS_API_KEY" \
  -H "Content-Type: application/json" \
  -H "X-Session-ID: task-1842" \
  -d '{"model": "auto", "input": "Explain this stack trace: ..."}'

Pick your tool

01Claude CodeAnthropic Messages

Create an API key

Point Claude Code at Modeless

Check it works

02Codex CLIOpenAI Responses

Create an API key

Add a provider to ~/.codex/config.toml

Export your key

Check it works

03OpenCodeOpenAI Chat Completions

Create an API key

Add Modeless to opencode.json

Check it works

04ClineOpenAI Chat Completions

Create an API key

Open Cline settings

Check it works

05CursorOpenAI Chat Completions

Create an API key

Settings → Models

Check it works

For code you write yourself

Base URL

Authentication

Endpoints

Models

Sessions

Errors