Module amp 

Amp (ampcode.com): one JSON document per thread at ~/.local/share/amp/threads/<T-…>.json.

The native Body is Amp’s thread document — the same shape the local-first CLI wrote to disk and amp threads export emits today: {v, id, created, title, env, messages, …}. Only messages is typed (as raw JSON values); every other top-level key rides in extra, so the document round-trips without loss across schema eras (the legacy local-first files and the modern server-side export differ in bookkeeping keys like meta, protocolMessageID, and readAt, and in tool names — legacy Bash{cmd,cwd} vs modern shell_command{command,workdir} — all of which this codec accepts).

Amp already follows the Anthropic convention: assistant messages carry tool_use blocks and the user messages that follow carry tool_result blocks, so messages map 1:1 onto Common. Turn attribution lives on the assistant message itself (usage.model, usage.timestamp, state).

Current Amp CLI versions are server-authoritative: they neither read nor write the local threads/ directory (verified by bisection — a thread file placed there is invisible to amp threads list/export). The store therefore targets the legacy local-first location, which era-matched CLI versions (@sourcegraph/amp ≤ early 2026) read and resume natively. Bisecting against such a version: created is the one top-level field its parser requires (from_common always writes it); v, agentMode, nextMessageId, and env are optional but observed-shaped.

Known representational losses through Common (the native body keeps them; they do not survive from_common):

• run.progress, run.trackFiles, and per-run ~debug on tool results; cancelled / rejected-by-user result statuses collapse to is_error: true text results.
• Message bookkeeping: userState, fileMentions, interrupted, originalToolUseInput, turnElapsedMs, readAt, protocolMessageID, and usage.credits.
• An assistant with no stop reason renders as end_turn (Amp requires a state); StopReason::Aborted maps to state: {type: "cancelled"}.
• sourcePath on image blocks and signature-less thinking providers.
• Shared-thread-era kinds never observed locally (role: "parent" messages, manual_bash_invocation blocks) pass through the native body unmodeled and carry nothing into Common.

Structs

Amp

The Amp harness marker.

AmpStore

Reads and writes Amp threads as JSON documents in a flat directory (default ~/.local/share/amp/threads).

Thread

Amp’s thread document. messages holds each message as raw JSON — the codec interprets them, serde stays lossless — and every other top-level key (v, id, created, title, env, agentMode, ~debug, …) passes through extra untouched.