2026-03-19 23:03:33Claude (MCP):
[mcp] Add SDK vs CLI finding: SDK lacks Claude Code system prompt and tools
Minsky/Agent_IRC_Architecture.md ..
@@ 140,6 140,14 @@
The Claude Code CLI is designed for a human at a terminal — prompt handling, display rendering, keybindings are all overhead when the consumer is a daemon. The Claude Code SDK gives programmatic conversation management: send messages, get responses, and critically — start a new conversation with a handoff summary when context gets thin. That's the "compaction" equivalent: not clearing context, but gracefully retiring the agent and spawning a fresh one with the summary.
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**Important finding (2026-03-19):** The Claude Code SDK does **not** include Claude Code's system prompt or tool definitions. Those are baked into the CLI binary. This means SDK agents start with a blank slate — no file read/write/edit tools, no git tools, no Bash tool. Options:
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1. **Write your own system prompt + tools from scratch** with the SDK. Full lifecycle control, but you lose Claude Code's well-tuned coding toolset.
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2. **Run the CLI in `--print` mode** to get the full Claude Code toolset. Less session lifecycle control, but agents get the same capabilities as interactive Claude Code.
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3. **Hybrid**: use the SDK for session management but shell out to the CLI for actual coding tasks.
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This is an open design question for the supervisor. The system prompt and tool definitions may be significant for coding task quality — worth experimenting before committing to an approach.