microsoft/autogen · error · Error

Failed to create session

Error message

Failed to create session

What it means

Thrown by SessionAPI.createSession when POST /sessions/ returns a body with falsy status. The method force-injects user_id into the payload before sending; failures are usually validation of the session body (missing team, invalid windows/websocket config) or backend DB write errors, all reported through the status envelope.

Source

Thrown at python/packages/autogen-studio/frontend/src/components/views/playground/api.ts:47

  }

  async createSession(
    sessionData: Partial<Session>,
    userId: string
  ): Promise<Session> {
    const session = {
      ...sessionData,
      user_id: userId, // Ensure user_id is included
    };

    const response = await fetch(`${this.getBaseUrl()}/sessions/`, {
      method: "POST",
      headers: this.getHeaders(),
      body: JSON.stringify(session),
    });
    const data = await response.json();
    if (!data.status)
      throw new Error(data.message || "Failed to create session");
    return data.data;
  }

  async updateSession(
    sessionId: number,
    sessionData: Partial<Session>,
    userId: string
  ): Promise<Session> {
    const session = {
      ...sessionData,
      id: sessionId,
      user_id: userId, // Ensure user_id is included
    };

    const response = await fetch(
      `${this.getBaseUrl()}/sessions/${sessionId}?user_id=${userId}`,
      {
        method: "PUT",

View on GitHub (pinned to 027ecf0a37)

Solutions

1. Read data.message — FastAPI validation errors are usually surfaced there
2. Ensure a valid team/component reference exists before creating the session (save the team first)
3. POST the same payload via curl to see the raw 422/validation detail
4. Confirm user_id exists on the backend (create it via the user endpoint or login flow first)

function isValidSessionPayload(s: Partial<Session>): boolean {
  return !!(s && s.team); // adjust to backend's required fields
}

try {
  return await sessionAPI.createSession(sessionData, userId);
} catch (e) {
  notify(`Session not created: ${e instanceof Error ? e.message : e}`);
  return null;
}

When it happens

Trigger: POST /sessions/ with {...sessionData, user_id} returning {status:false}: required fields missing (e.g. no team or invalid component), user_id not registered in backend, DB constraint violation, auth failure.

Common situations: Creating a session before a team is selected/saved, sessionData built from an unsaved gallery component, backend model/schema version drift rejecting the JSON payload.

Related errors

• Failed to fetch sessions
• Failed to fetch session
• Failed to update session
• Failed to fetch session runs
• Failed to delete session

AI-assisted analysis of microsoft/autogen@027ecf0a37 (2026-08-15). Data as JSON: /api/errors/1a32c10084b0dec5. Report an issue: GitHub.