Chat Deployment

Deploy your workflow as a conversational chat interface that users can interact with via a shareable link or embedded widget. Chat supports multi-turn conversations, file uploads, and voice input.

A deployed chat interface showing a conversation with Friendly Assistant

Every chat message triggers a fresh workflow execution, with the full conversation history passed in as context. Responses stream back to the user in real time.

Chat executions run against your workflow's active deployment snapshot. Publish a new deployment after making canvas changes so the chat uses the updated version.

Creating a Chat

Open your workflow, click Deploy, and select the Chat tab. You'll see the chat configuration panel:

Chat deployment configuration panel showing URL, Title, Output, Access control, and Welcome message fields

Configure the following fields, then click Launch Chat:

Field	Description
URL	Slug that forms the public URL, e.g. `https://www.sim.ai/chat/your-slug`. Lowercase letters, numbers, and hyphens only. Must be unique across all workspaces.
Title	Display name shown in the chat header.
Output	Output fields from your workflow blocks returned as the chat response. At least one must be selected.
Welcome Message	Greeting shown before the user sends their first message. Defaults to `"Hi there! How can I help you today?"`.
Access Control	Controls who can access the chat. See Access Control below.

The output dropdown groups available fields by block. For an Agent block, you can choose from content, model, tokens, toolCalls, providerTiming, and cost. In most cases, selecting content from the final Agent block is all you need — it streams the agent's text response directly to the user.

Access Control

Mode	Description
Public	Anyone with the link can chat — no authentication required
Password	Users must enter a password before they can start chatting
Email	Only specific email addresses or domains can access. Users verify with a 6-digit OTP sent to their email
SSO	OIDC-based single sign-on (enterprise only)

Email access: Add individual addresses (user@example.com) or entire domains (@example.com) to the Allowed emails field. Users receive a one-time 6-digit OTP to their inbox — once verified, they can chat for the duration of their session.

Password access: A password field appears when this mode is selected. Share the password with users directly; they enter it before the conversation begins.

SSO: Uses OIDC to authenticate users through your identity provider. Available on enterprise plans.

Direct Link

https://www.sim.ai/chat/your-slug

Iframe

<iframe
  src="https://www.sim.ai/chat/your-slug"
  width="100%"
  height="600"
  frameborder="0"
  title="Chat"
></iframe>

API Submission

You can also send messages to a chat programmatically. Responses are streamed using server-sent events (SSE).

curl -X POST https://www.sim.ai/api/chat/your-slug \
  -H "Content-Type: application/json" \
  -d '{
    "input": "Hello, I need help with my order",
    "conversationId": "optional-conversation-id"
  }'

const response = await fetch('https://www.sim.ai/api/chat/your-slug', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({
    input: 'Hello, I need help with my order',
    conversationId: 'optional-conversation-id'
  })
});

// Response is an SSE stream
const reader = response.body?.getReader();
const decoder = new TextDecoder();

while (true) {
  const { done, value } = await reader!.read();
  if (done) break;
  console.log(decoder.decode(value));
}

With File Uploads

curl -X POST https://www.sim.ai/api/chat/your-slug \
  -H "Content-Type: application/json" \
  -d '{
    "input": "What does this document say?",
    "files": [{
      "name": "report.pdf",
      "type": "application/pdf",
      "size": 1048576,
      "data": "data:application/pdf;base64,..."
    }]
  }'

Protected Chats

For password-protected chats, include the password in the request body:

curl -X POST https://www.sim.ai/api/chat/your-slug \
  -H "Content-Type: application/json" \
  -d '{ "password": "secret", "input": "Hello" }'

For email-protected chats, authenticate with OTP first:

# Step 1: Request OTP — sends a 6-digit code to the email address
curl -X POST https://www.sim.ai/api/chat/your-slug/otp \
  -H "Content-Type: application/json" \
  -d '{ "email": "allowed@example.com" }'

# Step 2: Verify OTP — save the Set-Cookie header for subsequent requests
curl -X PUT https://www.sim.ai/api/chat/your-slug/otp \
  -H "Content-Type: application/json" \
  -c cookies.txt \
  -d '{ "email": "allowed@example.com", "otp": "123456" }'

# Step 3: Send messages using the auth cookie from Step 2
curl -X POST https://www.sim.ai/api/chat/your-slug \
  -H "Content-Type: application/json" \
  -b cookies.txt \
  -d '{ "input": "Hello" }'

Troubleshooting

Chat returns 403 — The deployment is inactive. Open the Deploy modal and re-deploy the workflow.

"At least one output block is required" — No output field is selected in the Output dropdown. Open the Deploy modal, go to the Chat tab, and select at least one output from a block.

OTP email not arriving — Confirm the email address is on the allowed list and check spam folders. OTP codes expire after 15 minutes and can be resent after a 30-second cooldown.

Chat not loading in iframe — Check your site's Content Security Policy allows iframes from sim.ai.

Responses not updating after workflow changes — Chat uses the active deployment snapshot. Publish a new deployment from the Deploy modal to pick up your latest changes.

Common Questions

API deployment exposes your workflow as a REST endpoint for programmatic use. Chat wraps the workflow in a hosted conversational UI with streaming, file uploads, voice input, and access control — no application code required to use it.

For workflows built around Agent blocks, select the content field from the final Agent block — this streams the agent's text response to the user. You can select multiple fields if your workflow produces structured output you want to expose.

Each message triggers a new workflow execution. The full conversation history — all prior user messages and assistant responses — is passed as context so your workflow can maintain continuity across turns.

When a user opens an email-protected chat, they enter their email address. If it matches the allowed list, Sim sends a 6-digit OTP to that address. The user enters the code, and a session cookie is set for the duration of their visit.

There is no hard limit on message length. Very long messages may impact response time depending on your workflow's model context window.

Yes, any workflow can be deployed as a chat. The chat sends the user's message as the workflow input and streams the selected block outputs back as the response.