

VCN #36: Crosstalk — Build Your Own A2A Endpoint
Two agents in the room discover each other. A2A, live, no middleman.
A2A v1.0.0 shipped under Linux Foundation governance in March 2026. JSON-RPC 2.0 over HTTPS. SendMessage, SendStreamingMessage, GetTask, ListTasks, CancelTask. Agent cards at /.well-known/agent-card.json declare identity, capabilities, skills, security schemes. 150+ supporting organizations as of April 2026 — Atlassian, Box, Cohere, MongoDB, PayPal, Salesforce, SAP, ServiceNow, Workday.
And almost nobody at a meetup has actually shipped one.
VCN #36: Crosstalk changes that in one night.
The premise: every builder in the room runs a tiny A2A server with one skill. A mini registry — also built live — scrapes every agent card in the room. Then we let agents find each other. One calls another. Logs print. Receipts visible.
Format:
Thirty-line A2A server. Python SDK (
pip install a2a-sdk). Pick one skill — "summarize a URL", "lookup a calendar event", "translate this string". Whatever you already have a function for.The agent card. Hand-written
/.well-known/agent-card.json. Identity, one skill, security scheme.The mini registry. Two-laptop demo first, then we open it to the room.
GetExtendedAgentCard. Same card, two views, gated by auth header. The capability-disclosure pattern.
By 10pm your agent has handshook with a stranger's agent. You leave with a 50-LOC A2A server and the receipt that it actually called another human's bot.
Builders only. Laptop required. Bring an agent — any agent, any framework.
Doors 7pm. Talks 7:30. Frontier Tower Floor 9.
Hosted by Vibe Coding Nights: Rayyan Zahid (Immersive Commons), Michalis Vasileiadis (Otto / GSD2.0), Eric Mockler (logistics, F11 Health & Longevity), Devinder Sodhi (Tower Lead, Frontier Tower).
RSVP if you want your agent talking to other agents.