DeepSeek Harness session compatibility

This adapter was verified against DeepSeek Harness dsh-v0.1.0-rc.8, commit 141eb6f. DSH is a developer preview and explicitly does not promise broad session-format compatibility yet.

Supported containers

Container	Support	Source contract
Official export ZIP	Yes; root session	session-export.ts
Raw session.jsonl	Yes	format.ts
session.jsonl.zstd	Yes; complete frames	zstd.ts
SQLite persistence	No export adapter in DSH rc.8	session-log-export README

The official ZIP uses session.jsonl at the root, optional descendant logs below subagents/<id>/session.jsonl, and referenced images below media/. Version 0.1 selects only the root and reports how many descendant logs are present.

Logical records

The first JSONL record is a session header. Later records are event envelopes with type, seq, time, and data. dsh-showcase extracts these presentation events:

• user/message from a direct human source;
• tool/call;
• tool/result, with diff-like metadata preferred;
• assistant/message;
• assistant/chunk text only as a fallback when no assembled message exists.

It intentionally excludes request headers, system/tools prompts, reasoning deltas/blocks, and plugin snapshots from scene selection.

Packed chunk rows

DSH can pack token deltas into text-chunks, reasoning-chunks, and tool-call-chunks storage rows. The reader expands their sequence/time gaps according to the official storage codec.

Zstandard frames

DSH stores the header and each durable append batch as independent checksummed Zstandard frames. A one-shot decompressor reads only one frame, so dsh-showcase first scans frame boundaries and then validates/decompresses each complete frame. An incomplete final frame is ignored with a warning; corrupt complete frames fail closed.

Compatibility policy

• The adapter reports the observed session version and warns on a version other than v0.
• New event vocabulary is tolerated because showcase generation is a read-only projection, not session reconstruction.
• Malformed JSON, malformed packed rows, invalid Zstandard structures, and missing ZIP roots are rejected.
• Every upstream release is tested with a pinned synthetic/official-shaped fixture before compatibility claims change.