2. A2A Setup

All A2A services are hosted on the same domain and follow one pattern:

https://studio.orbitfin.ai/<service>/a2a

Step 1: Obtain API Key

The caller needs an API Key under an Agent Builder account as an identity credential — all actual A2A calls must carry it.

Step 2: Confirm the A2A Service Address

Service	A2A endpoint
Agent Builder	https://studio.orbitfin.ai/builder/a2a
Agentic Chat	https://studio.orbitfin.ai/research/a2a

Step 3: Read the Agent Card and Verify Connectivity

The Agent Card is a publicly readable "business card" document — no authentication required. It confirms the service is reachable and lists what it can currently do: the service name, its description, the supported authentication methods, and the full set of capabilities (Skills).

Append /.well-known/agent-card.json to any endpoint above:

Service	Agent Card URL
Agent Builder	https://studio.orbitfin.ai/builder/a2a/.well-known/agent-card.json
Agentic Chat	https://studio.orbitfin.ai/research/a2a/.well-known/agent-card.json

If the document comes back, this step is configured correctly. Note that each service publishes its own card with its own Skill list — read both if you plan to call both.

Step 4 — Authenticate your calls

Each Agent Card declares two accepted authentication methods. Either one is sufficient — do not send both.

Method	Usage
API Key	Request header X-API-Key: YOUR_API_KEY
Bearer Token	Request header Authorization: Bearer YOUR_API_KEY

curl -X POST https://studio.orbitfin.ai/builder/a2a \
  -H "X-API-Key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{ ... }'

Calls without a valid credential will be rejected; reading the Agent Card itself does not require authentication.

Protocol Version

This endpoint accepts A2A v1.0 only (PascalCase method names: SendMessage / SendStreamingMessage / GetTask / CancelTask). Legacy v0.3 method names such as message/send are not supported. As a matter of standard practice, include the following request header:

A2A-Version: 1.0