A shipping company from which Nordlicht Reisen GmbH requests ferries for groups runs an agent of its own that accepts requests via A2A. Lesson 1.2 hinted at the case (exercise 1) and said: This agent would be the team's first A2A connection, because it lies beyond an organization boundary. This lesson integrates it. It asks about the path (in code, in the service or through MCP), about security (what leaves the house, whom do we trust with the answer) and about middleware, with which such connections do not have to rebuild their protective functions every time.
Prior knowledge. "Lesson 1.2" chose the protocols, read the state of A2A in Foundry (protocol 1.0 generally available, the older a2a_preview in preview, .NET packages prerelease, path of the agent card open) and checked the channel plan as data. "AI track, lesson T8.2" shows the agent as an MCP client, "T2.4" middleware around the chat client, "AI-103, lesson 2.5" the approval for MCP tools, "lesson 2.8" the flow in stages and "lesson 2.9" approvals and edge cases. What goes beyond that starts here: middleware around an agent, not around a chat client, and the connection of a foreign agent.
New in this lesson. The partner is called reederei (not an agent of the team, so the name is not in the set agenten of the check from 1.2). The channel plan gets a twelfth channel, transport -> reederei, protocol a2a. It is request only (A0): A binding booking would be a payment and stays with a person (A3, M-05). Assumptions of the task: The partner speaks A2A in version 1.0; the deadline for an answer is 30 seconds; only destination, period and number of people go to the partner, never participant lists (M-07).
The requirement
All numbers are assumptions of the task.
| No. | Requirement | Type | Measure | Weight | Source |
|---|---|---|---|---|---|
| 2.11-01 | Only destination, period and number of people go to the partner. | R | 0 participant names in the call | Must | M-07, M-08 |
| 2.11-02 | The partner's answer is text from outside and is never obeyed (R-11). | R | 0 instructions from the answer | Must | M-12 |
| 2.11-03 | If the partner fails or does not answer, the team goes on. | R | Fallback within 30 seconds | Must | M-02 |
| 2.11-04 | Only transport may have an A2A channel. |
R | 1 A2A channel, checked in the build | Must | F-04, F-05 |
| 2.11-05 | Every call of the partner is in the log, without content. | Q | Name, duration, result | Should | Lesson 3.4 |