ACP_ATTACHMENT_FENCE_BEGIN

const ACP_ATTACHMENT_FENCE_BEGIN: "[BEGIN CLIENT-PROVIDED ATTACHMENT]" = '[BEGIN CLIENT-PROVIDED ATTACHMENT]'

Defined in: packages/core/src/utils/untrustedText.ts:55

[[EXT-46]] — the fence the ACP server quotes a prompt’s non-text content blocks inside, emitted by @gaunt-sloth/agent’s modules/acp/acpAgentApp.ts.

An ACP client attaches content blocks to a prompt, and the ones that are not the user’s own typed text carry values the user did not author: a resource link’s name, uri and description come from the editor, the filesystem or an MCP server, and a block’s type is an arbitrary client string by the v2 schema. The agent has to tell the model that something was attached — dropping it silently is worse — so those values are quoted into the same message as the user’s words, which is the situation this module exists for.