Summary
Gemini CLI v0.57.0 (stable, 2026-08-25T18:37Z) includes packages/a2a-server — an Agent2Agent protocol server — in its release tag, and the package is published to npm as @google/gemini-cli-a2a-server@0.57.0. The release notes merge a wave of '[SSR Agent]' fixes touching a2a-server tests, TUI execution timeouts, subagent gating and handoff regressions, indicating active maintenance rather than an abandoned experiment. Gemini CLI 0.60.0 later promotes MCP OAuth, path-boundary, environment-consent, tool-output-provenance and sandbox-isolation fixes to stable. There is still no official announcement, documentation page, or usage guidance for the A2A server from Google.
Why it matters
Agent-to-agent interop has moved from a main-branch experiment (observed 2026-08-19) to a shipped, installable Google artifact in a stable runtime — a second major organization after Anthropic exposing inter-agent messaging in stable tooling. Because it is undocumented and unannounced, treat it as a directional signal of Google's roadmap, not a build target: the surface can change without notice.
Technical details
| Release | v0.57.0 stable published 2026-08-25T18:37:14Z; packages/a2a-server present in the v0.57.0 tag tree (verified via git tree API) |
|---|---|
| Npm | @google/gemini-cli-a2a-server@0.57.0 published; package scoped under @google |
| Release Notes | multiple '[SSR Agent]' fixes merged into v0.57.0: a2a-server test migration, TUI execution timeouts, subagent gating when agents mode disabled, sub-agent handoff token regression, cli_help markdown formatting |
| Package Contents | a2a-server/src includes agent executor/task modules, command registry, extensions; development-extension-rfc.md present |
| Status | shipped-but-undocumented: no official announcement, docs, or usage telemetry as of 2026-08-28 |
| Related Kb | upgrade of the 2026-08-19 early indication (a2a-server main-branch only) to a stable-line artifact; evidence item for trend coding-agents-multi-agent-runtimes |
Updates
2026-09-02 0.58.0 stable (9/1T20:51Z): macOS Seatbelt sandbox now isolates Docker and container-runtime sockets and binaries (sandbox hardening); a2a-server fix — stale cancellation error cleared on new message turns (a2a-server continues in the stable release line); consistent symlink evaluation in ignore-path handling; top-level safety checkers declared in write-policy configuration; history rollback and retry-nudge fixes. a2a-server documentation still absent (watch item). 0.59.0-preview.0 published 9/1T20:19Z
2026-09-04 No new stable in window (latest remains 0.58.0, 9/1). Nightlies: 0.59.0-nightly (9/2): web-fetch destination validation + connection routing fix; 0.60.0-nightly (9/4) security cluster — RFC 9207 issuer identification enforced in the MCP OAuth flow, macOS Seatbelt temp-dir isolation, extension-loader path-boundary hardening, hardcoded Google CrUX API key removed from chrome-devtools-mcp. a2a-server docs watch: packages/a2a-server now carries a README.md, but it is a 171-byte 'experimental and under active development' stub — still no usage/setup documentation. Stays TRIAL
Tags
gemini-cligooglea2aagent-to-agentprotocolmulti-agentcli