MCP CLI-Ent 1.4.0

[1.4.0] - 2026-07-28

Added

• Dual-era MCP 2026-07-28 support. A new protocolVersion config field (default "auto") probes server/discover once per server, classifies it as modern (stateless, per-request _meta) or legacy (initialize handshake), caches the verdict, and shapes each request accordingly. The modern path injects _meta and the MCP-Protocol-Version / Mcp-Method / Mcp-Name headers; the legacy path is unchanged. Pin a version (e.g. "2025-11-25") to skip detection.
• meta envelope for the tools index. list-tools and bare mcp-cli-ent now emit {"meta":{"errors":{...}}, "servers":{...}}. Per-server fetch errors (negative-cache skip, connect failure, list failure) land in meta.errors so agents reading only stdout see why a server is missing instead of its silent absence. meta is omitted entirely when nothing failed.

Changed

• Machine output is pure JSON. In default JSON mode, per-server fetch errors and era-detection diagnostics no longer print to stderr; they appear only in meta.errors. The human-readable lines remain available under --human and --verbose.
• Config fails closed when a legacy protocolVersion pin is paired with session.type: "stateless", since legacy needs a held initialize connection. Unknown protocolVersion values warn and fall back to auto.

Fixed

• Stdio transport data race on timeout. The stdio client now runs a single reader-owner goroutine with an id-keyed pending map; a context cancellation unregisters the waiter instead of leaking a goroutine that competed for the shared reader. Clean under go test -race.
• _meta injection preserves large integers. InjectMeta uses json.UseNumber so tool arguments keep exact number representation through the modern path.