You are building a multi-agent research system using the Claude Agent SDK.

Option B combines lossless persistence with selective restoration. Each agent should checkpoint structured records containing completed document IDs, extracted findings, source metadata, unresolved work, validation status, and schema version. A coordinator-level manifest records where those artifacts are stored and which pipeline stages completed. On resumption, the coordinator can skip the 12 completed documents and inject only the artifacts relevant to each restarted agent. Anthropic’s effective context-engineering guidance recommends structured note-taking outside the context window so agents can preserve project state across resets while loading only the information needed later. A vector store, option A, is useful for relevance retrieval but can omit exact details through similarity-based selection and is unsuitable as the sole recovery record. Option C fragments ownership of recovery state and makes cross-agent consistency difficult to verify. Option D preserves an extensive trace, but replaying a complete conversation wastes context and mixes obsolete instructions, intermediate reasoning, and redundant outputs. Structured checkpoints plus a manifest provide deterministic recovery, auditability, exact provenance, and efficient prompt reconstruction. Checkpoints should be written atomically and validated before the corresponding stage is marked complete.

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