{"version":"2.1.248","anchor":"sdk-control-messages-documented","canonical_anchor":"sdk-control-messages-documented","heading":"SDK control messages documented","tier":"internal","area":"SDK","scope":null,"heads_up":null,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.248\/e\/sdk-control-messages-documented","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.248","markdown":"### SDK control messages documented\n\nTwo SDK control messages got internal docs, including asking the host for a fresh token after a 401.\n\n**What**\n\nTwo messages exchanged between the CLI and an SDK host gained internal documentation: one relays JSON-RPC to an MCP server the SDK hosts, the other asks the host for a fresh OAuth access token after a 401 when the CLI has no refresh token of its own. Behaviour is unchanged.\n\n**Evidence**\n\n`@internal Request from the CLI subprocess to the SDK host for a fresh OAuth access token after a 401 with no local refresh token.`\n\n- Area: SDK\n- Tier: Under the hood\n- Useful: 1\/5\n- Signal: 2\/5"}