Call peer agents with the CLI

mf a2a supports two directions:

• Outbound: call a granted peer agent or raw A2A server.
• Inbound: expose the current agent and manage authorized callers.

The A2A API guide covers inbound exposure and External client tokens. This page focuses on outbound calls and task recovery.

Discover callable peers

mf a2a status

The result lists peer names/IDs the current agent may call and its in-flight outbound calls. Use a listed name or ID as the send target.

Send work

mf a2a send peer-name "Summarize today's open pull requests."
mf a2a send peer-name "Continue the review." --context-id aac_xxx
mf a2a send peer-name "Inspect this file." --input-file ./report.txt

By default the command waits for the result. Use --skill <id> when the remote Agent Card advertises a specific skill.

For a raw URL, provide its bearer through stdin or MF_A2A_BEARER:

printf '%s' "$A2A_TOKEN" |
  mf a2a send https://example.com/a2a "Run the check." --bearer -

HTTP, localhost, and private targets are rejected by default. The --allow-http-localhost escape hatch is for local development only.

Long tasks

Stream events:

mf a2a send peer-name "Run the full audit." --stream

Or submit and return immediately:

mf a2a send peer-name "Run the full audit." --async --json
mf a2a tasks list --state working
mf a2a tasks get peer-name aat_xxx --wait

The default client deadline is 900 seconds. --timeout 0 disables the client deadline, but it does not remove server-side task limits.

Recover or cancel

mf a2a tasks subscribe peer-name aat_xxx
mf a2a tasks get peer-name aat_xxx
mf a2a tasks cancel peer-name aat_xxx

subscribe reconnects to the task’s SSE stream. Use get after a disconnect before deciding whether to retry; resending a prompt can create separate work unless you deliberately reuse its context or task ID.

Manage inbound access

mf --agent-id agt_xxx a2a exposure get
mf --agent-id agt_xxx a2a exposure enable
mf --agent-id agt_xxx a2a callers list

Exposure and caller grants are separate controls. Creating a caller does not enable public exposure.

See also

• Call agents over A2A
• Scripting with mf
• CLI command reference