Migrating from Direct Tools to Sessions

This guide is for developers who are using Devcaster's direct tool execution pattern and want to migrate to sessions.

With sessions, you don't need to manage tool fetching, authentication, or execution yourself. You create a session and it handles everything. Your existing auth configs and connected accounts carry over, so your users don't need to re-authenticate.

If you're starting fresh, skip this guide and head to the Quickstart.

What changes

	Direct tools	Sessions
Tool discovery	You fetch specific tools by name/toolkit	Agent discovers tools at runtime via meta tools
Authentication	You manage connect links and wait for connections	In-chat auth prompts users automatically, or use `session.authorize()`
Execution	You call `tools.execute()` with version pinning	Agent executes tools through `DEVCASTER_MULTI_EXECUTE_TOOL`
Toolkit versions	You manage versions manually	Handled automatically

Migrating

Pass your existing auth configs to the session

You already have auth configs (e.g. ac_github_config, ac_slack_config). Pass them when creating a session so it uses your existing OAuth credentials and your users' connected accounts carry over.

from devcaster import Devcaster

devcaster = Devcaster()

# Before: manual tool fetching with user_id
# tools = devcaster.tools.get(user_id="user_123", toolkits=["GITHUB", "SLACK"])

# After: create a session with your existing auth configs
session = devcaster.create(
    user_id="user_123",
    auth_configs={
        "github": "ac_your_github_config",
        "slack": "ac_your_slack_config"
    }
)

import { Devcaster } from '@devcaster/core';
const devcaster = new Devcaster({ apiKey: 'your_api_key' });
// ---cut---
// Before: manual tool fetching with userId
// const tools = await devcaster.tools.get("user_123", { toolkits: ["GITHUB", "SLACK"] });

// After: create a session with your existing auth configs
const session = await devcaster.create("user_123", {
  authConfigs: {
    github: "ac_your_github_config",
    slack: "ac_your_slack_config",
  },
});

Since the session uses the same user_id and auth configs, it automatically picks up existing connected accounts. No re-authentication needed.

Replace manual tool fetching with session tools

Instead of fetching specific tools by name, get the session's meta tools. These let the agent discover, authenticate, and execute any tool at runtime.

# Before: manually specifying which tools to fetch
# tools = devcaster.tools.get(user_id="user_123", toolkits=["GITHUB"])

# After: session provides meta tools that handle discovery
tools = session.tools()

import { Devcaster } from '@devcaster/core';
const devcaster = new Devcaster({ apiKey: 'your_api_key' });
const session = await devcaster.create("user_123");
// ---cut---
// Before: manually specifying which tools to fetch
// const tools = await devcaster.tools.get("user_123", { toolkits: ["GITHUB"] });

// After: session provides meta tools that handle discovery
const tools = await session.tools();

Remove manual auth flows

If you were manually creating connect links and waiting for connections, sessions handle this automatically. When a tool requires authentication, the agent prompts the user with a connect link in-chat.

# Before: manual auth flow
# connection_request = devcaster.connected_accounts.link(
#     user_id="user_123",
#     auth_config_id="ac_your_github_config",
#     callback_url="https://your-app.com/callback"
# )
# redirect_url = connection_request.redirect_url

# After: auth happens automatically in-chat
# Or if you need to pre-authenticate outside of chat:
connection_request = session.authorize("github")
print(connection_request.redirect_url)
connected_account = connection_request.wait_for_connection()

import { Devcaster } from '@devcaster/core';
const devcaster = new Devcaster({ apiKey: 'your_api_key' });
const session = await devcaster.create("user_123");
// ---cut---
// Before: manual auth flow
// const connectionRequest = await devcaster.connectedAccounts.link("user_123", "ac_your_github_config", {
//   callbackUrl: "https://your-app.com/callback"
// });
// const redirectUrl = connectionRequest.redirectUrl;

// After: auth happens automatically in-chat
// Or if you need to pre-authenticate outside of chat:
const connectionRequest = await session.authorize("github", {
  callbackUrl: "https://your-app.com/callback",
});
console.log(connectionRequest.redirectUrl);
const connectedAccount = await connectionRequest.waitForConnection();

Remove toolkit version management

If you were pinning toolkit versions in your code or environment variables, you can remove that. Sessions handle versioning automatically.

# Before: manual version pinning
# devcaster = Devcaster(
#     toolkit_versions={
#         "github": "20251027_00",
#         "slack": "20251027_00",
#     }
# )

# After: no version management needed
devcaster = Devcaster()
session = devcaster.create(user_id="user_123")

import { Devcaster } from '@devcaster/core';
// ---cut---
// Before: manual version pinning
// const devcaster = new Devcaster({
//   toolkitVersions: {
//     github: "20251027_00",
//     slack: "20251027_00",
//   },
// });

// After: no version management needed
const devcaster = new Devcaster({ apiKey: 'your_api_key' });
const session = await devcaster.create("user_123");

Restricting toolkits

If you were fetching tools from specific toolkits, you can restrict the session to only those toolkits:

session = devcaster.create(
    user_id="user_123",
    toolkits=["github", "gmail", "slack"],
    auth_configs={
        "github": "ac_your_github_config",
        "gmail": "ac_your_gmail_config",
        "slack": "ac_your_slack_config"
    }
)

import { Devcaster } from '@devcaster/core';
const devcaster = new Devcaster({ apiKey: 'your_api_key' });
// ---cut---
const session = await devcaster.create("user_123", {
  toolkits: ["github", "gmail", "slack"],
  authConfigs: {
    github: "ac_your_github_config",
    gmail: "ac_your_gmail_config",
    slack: "ac_your_slack_config",
  },
});

Multiple connected accounts

If your users have multiple accounts for the same toolkit (e.g., work and personal Gmail), you can specify which one to use per session:

session = devcaster.create(
    user_id="user_123",
    auth_configs={
        "gmail": "ac_your_gmail_config"
    },
    connected_accounts={
        "gmail": "ca_work_gmail"
    }
)

import { Devcaster } from '@devcaster/core';
const devcaster = new Devcaster({ apiKey: 'your_api_key' });
// ---cut---
const session = await devcaster.create("user_123", {
  authConfigs: {
    gmail: "ac_your_gmail_config",
  },
  connectedAccounts: {
    gmail: "ca_work_gmail",
  },
});

If you don't specify, the most recently connected account is used. See Managing multiple connected accounts for details.

Triggers

Triggers don't work with sessions yet. Continue using them the same way you do today with devcaster.triggers.create(), devcaster.triggers.enable(), and webhook subscriptions.

See Triggers for setup instructions.

White labeling

If you've set up white-labeled OAuth screens with custom auth configs, those carry over automatically. Just pass the same auth config IDs to your session via auth_configs / authConfigs. Your users will continue to see your branding on consent screens.

See White-labeling authentication for more.

Migrating from Direct Tools to Sessions

What changes

Migrating

Restricting toolkits

Multiple connected accounts

Triggers

White labeling

Get started

Quickstart

Configuring Sessions

On this page