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MCP Inspector adds --protocol-era so a token-minting wrapper stops writing bearer tokens to disk on every launch
Before PR #2372 (merged 2026-09-14) the only way to set protocolEra was an mcp.json entry, which for a wrapper minting short-lived bearer tokens meant persisting the token to disk each launch. The new --protocol-era <legacy|auto|modern> flag works on all three clients and reuses isProtocolEra, the same guard mcp.json reads go through, so flag and file accept identical values. Unlike --header it is accepted for stdio, since the era is transport-agnostic, and like --header and --connect-timeout it overrides a catalog entry's value for that run.
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