A2A API Key credential behavior

  • Release version: Zurich
  • Updated June 11, 2026
  • 1 minute to read
  • Starting in Now Assist AI Agents 7.1.x, the header included in each A2A request is driven by the API Key credential record and it is not injected automatically by the flow action.

    Starting in Now Assist AI Agents 7.1.x, A2A flow actions no longer inject an Authorization: Bearer header automatically. The header included in each request is now driven entirely by the API Key credential record bound to the external agent's Connection & Credential Alias.

    OAuth-based external agents, and API Key endpoints whose existing credential record already aligns with the endpoint's expectations, are unaffected. You only need to act if your remote A2A endpoint requires a specific header name or a scheme prefix.

    Resolve 401 or 403 errors after upgrade

    If your A2A endpoint returns a 401 or 403 after upgrading, update the API Key credential record bound to your external agent.
    1. Open the api_key_credentials record bound to your A2A external agent. Navigate to the record via the Connection & Credential Alias on the external-agent provider.
    2. If the endpoint requires a specific header name (for example, x-api-key instead of Authorization), set the API Key Header (api_key_header_name) field to the header name the endpoint expects.
    3. If the endpoint requires a scheme prefix on the value (for example, Bearer for Google A2A), include the prefix directly in the API Key (api_key) field value — for example, change AIza... to Bearer AIza....
      Note:
      The API Key Prefix field is not currently applied by the A2A flow action; embed the scheme in the API Key value instead.
    4. Save the record and re-test the external agent end-to-end.

    Wizard-created credential records

    The wizard creates a working API Key credential record for most A2A endpoints. Only edit the credential record manually if your remote endpoint has specific requirements that the default credential does not satisfy.

    • Custom header name (for example, x-api-key): Set the API Key Header (api_key_header_name) field to the header name the endpoint expects.
    • Scheme prefix on the value (for example, Bearer for Google A2A): Include the prefix directly in the API Key field value — for example, Bearer <your-key>. Don't use the API Key Prefix field; it is not applied by the A2A flow action.