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title: “Invoke A2A agents from Claude”

description: “Install the Phinite Connector in Claude, discover registry agents, run tasks, and complete credential setup for integrated tools.” icon: “plug” The Phinite Connector is a Claude plugin that connects your chat session to your organisation’s Agent Registry over the Agent-to-Agent (A2A) protocol. After you connect, Claude can discover published agents in your workspace, call them on your behalf, and guide you through credential setup when an agent needs Gmail, Slack, GitHub, or other integrations. This guide is for end users calling registry agents from Claude. To publish agents into the registry, see Expose your agent graph and the Agent Registry overview. This connector is separate from Use Phinite Docs in AI Tools, which searches Phinite documentation — not your workspace agents.

What the Phinite Connector is

Once installed and authenticated, Claude acts as a gateway to your org’s A2A registry: - Discover agents by name, description, skills, and tags — the same metadata builders define in Agent Cards. - Invoke a chosen agent with natural-language requests. - Continue multi-turn conversations with the same agent using a task ID returned by the A2A runtime. - Authorize tool credentials through Phinite’s public configuration page when an agent requires external services. Builders expose agents from Graph Studio; you consume them from Claude without opening the full Phinite app for every task.

Install and connect

Visit the Phinite plugins marketplace and add the Phinite plugin to your Claude environment. After the plugin appears in Claude, click Install, then Connect to authorize the connector. In the sign-in window, use the same credentials you use for Phinite — Google account or email login. Grant Claude permission to access your Phinite account when prompted. When authentication succeeds, the connector is ready to use.

Three core tools

The connector exposes three tools Claude can call automatically. You rarely invoke them manually — describe your goal in natural language and Claude selects the right tool.

list_agents

PurposeReturn published A2A agents available in your organisation
ReturnsUp to 50 agents (unfiltered)
Best forBrowsing the full catalog when you have no specific search criteria
Use this when you want a broad view of what is registered. For targeted tasks, prefer discover_agents.
PurposeFind agents that match your needs using natural language
Search scopeAgent name, description, and skill names
Best forMost user requests — Claude typically calls this first
Parameters:
ParameterRequiredDescription
queryYesDescribe what you need in plain language (for example, send email to my team)
statusNoFilter by deployment status: live or test — see Agent Cards & builds
limitNoMaximum results to return (default 5)
Discovery behaviour mirrors the workspace Agent Registry catalog: builders control what you see through visibility, skills, tags, and test/live status.

call_agent

PurposeSend a message to a specific registry agent and receive its response
Best forExecuting work through a specialised agent after discovery
Parameters:
ParameterRequiredDescription
registry_idYesThe agent’s unique registry identifier (from list_agents or discover_agents) — same as Agent Registry ID in the product UI
messageYesYour request or follow-up text to the agent
task_idNoRequired for continuing a multi-turn conversation with the same agent
The underlying protocol is A2A SendMessage against the agent’s hosted endpoint. See Endpoints & lifecycle for URL patterns and auth.

Workflows

Single-turn (one request, one result)

1. You describe what you need. 2. Claude calls discover_agents with your request. 3. The registry returns matching agents. 4. Claude calls call_agent with the selected agent’s registry_id and your message. 5. The agent runs and returns results; Claude presents them to you.

Multi-turn (same agent, continued context)

Some agents need back-and-forth — clarifying questions, iterative analysis, or staged workflows. 1. Claude calls call_agent with your initial message. 2. The agent responds and includes a **task_id** in the response. 3. For follow-up messages, Claude passes that **task_id** so the agent retains conversation context. 4. Repeat until the task completes. If a follow-up seems to “forget” earlier context, the session may have started a new task without the previous task_id. Rephrase as a continuation or ask Claude to continue the same agent task.

Credential setup

Many registry agents call Integrations Hub tools (Gmail, Slack, GitHub, and others). If required credentials are not yet configured for your session, the agent cannot proceed until you authorise them.

When credentials are needed

1. You request a task that depends on an external integration. 2. The agent returns a credential setup link (or Claude surfaces it from the agent response). 3. You complete setup once; the agent can then run the task. This corresponds to the A2A **TASK_STATE_AUTH_REQUIRED** state when a build expects tool configuration but no valid config_id is attached to the call.

Configure credentials on the public page

Click the link Claude provides. Links are tied to your account and registry context — do not share them. You may need to log in to Phinite with the same Google account or email you used for the connector. Phinite opens **/public/agent-config** with the integrations that agent requires. Fill in credentials for each service — for example Gmail for email tasks, Slack tokens for messaging, GitHub tokens for repository work. After you submit, Phinite stores the configuration securely. Return to Claude and retry or continue your request; the agent can now use those tools on your behalf. Integrations available on the form match what the agent builder configured when exposing the graph. See Integrations Hub overview for the types of connectors agents may require.

Best practices

Do

- Be specific in your requests so Claude can pick the right agent and skill. - Use natural language — Claude chooses discover_agents vs list_agents automatically. - Complete credential setup promptly — agents cannot call external tools until configuration is saved. - Use consistent accounts across Phinite login and integration OAuth where possible.

Don’t

- Don’t share credential setup links — they are personalised to your account and registry session. - Don’t assume credentials last indefinitely — see Security & credential lifecycle below.

Security and credential lifecycle

Use only official Claude and Phinite applications. Grant access only to integrations an agent genuinely needs for your task.
TopicBehaviour
StorageIntegration credentials are stored and managed by Phinite infrastructure, not in Claude’s chat history
Setup linksPersonalised; treat them like sensitive sign-in URLs
Validity windowConfigured credentials remain valid for approximately 5 hours from the time you submit the public config form
Re-authenticationAfter expiry, the agent prompts you to configure credentials again — this is expected security behaviour
Account confidentialityKeep your Phinite and third-party account credentials private
For builders: visibility (public vs organisation) and API key rules are documented in Endpoints & lifecycle. How the registry fits into publish and compose workflows. Workspace search and filters — the same metadata discover_agents uses. Hosted A2A URLs, test vs live, and authentication. A2A terms, connector tools, and UI label mapping.