New strings in the Claude Code binary suggest new experimental task execution, potential f

EXHIBIT 1249 · URGENT

Sep 9, 2026 01:07 UTC binary @anthropic-ai/claude-code-darwin-arm64

New strings in the Claude Code binary suggest new experimental task execution, potential file attachments in messages, and an internal artifact endpoint.

READY TO POST:

anthropic's claude-code binary shows strings for `client.experimental.tasks.callToolStream()`, hinting at new ways to execute tasks programmatically. could be a big deal for developers!

interesting strings in the latest claude-code binary point to 'files api upload (beta surface)' and 'file_attachments' in messages. are we getting better file handling or multimodal inputs for claude code soon?

⚠️ FROM COMPILED BINARY — lower confidence, verify before posting. (May include bundled-dependency strings, not just first-party changes.) @anthropic-ai/claude-code-darwin-arm64 2.1.263 -> 2.1.266: +11085 strings, -9982 strings, 15 interesting [model_id] (1) + /$bunfs/root/claude-code.d.ts-6dbf94ed.txt.zst [feature_flag] (12) + " requires task-based execution. Use client.experimental.tasks.callToolStream() instead. + ${e?Rt:"Every message you send is to the user."} Worker results and system notifications are internal signals, not conversation partners \u2014 never thank or acknowledge them. Summarize new information for the user as it arrives. + ' on Vertex: this model's Vertex serving stack rejects the tool-search beta header (pre-4.5 generation).. + <${d2}>No completion record was found for them in the previous session. ${k} Task ids in this notification beginning with "${je}" are internal scan markers, not tasks.</${d2}> + @internal 'setup' when the session process never started, 'run' when it exited. + @internal Cold-start telemetry for hosted (CCR) sessions: named startup phases and resume-hydration counters (StartupTiming in src/utils/startupTiming.ts). Absent elsewhere. + @internal Files a remote client attached to this prompt (each {file_uuid, file_name, is_image?, sha256?, file_size?}; src/bridge/inboundAttachmentSchema.ts reads them). Typed like SDKUserMessageReplay.file_attachments so the two message types stay assignable. + @internal How a self-hosted runner's session process ended, on the result the runner synthesizes for it. + @internal Replayed history rather than a live message (stamped by the Remote Control bridge when it flushes history to the session server). + @internal Replayed history rather than a live message: the Remote Control bridge stamps it on the messages it flushes to the session server, which also stamps it on deliveries it replays. + @internal Set by the self-hosted runner on the result it synthesizes when