[fireboltdude1357]

While agents stream, every message and turn-item write re-parsed its whole JSON payload on T3's main thread just to read back two timestamps. That's main-thread time taken from every other request. This carries upstream pingdotgg#25162, which encodes those timestamps directly instead.

It's merged onto upstream 0b0417a without conflicts, and its diff is identical to upstream's (git patch-id). Upstream's CI never ran on it, and its author is unvouched, so it was reviewed line by line:

• Scope. It changes two files: ProjectionStore.ts (+5/−5, a new encodePayloadTimestamp and three call sites) and one test. There are no network, process or file calls, no dependency or lockfile changes, no dynamic code and no auth changes.
• Stored bytes. They don't change. payload_json is the same encoder output as before. The created_at and updated_at columns are now written with Schema.DateTimeUtcFromString, the same codec the payload schemas use for those fields, and none of the 24 turn-item members overrides it.

Evidence. The PR's own test asserts that the indexed timestamps equal the ones in the payload. It passes with and without the change, because this is a pure performance change. A timing harness checked the mechanism instead: 300 streamed write pairs with about 215 KB of text each, 3 runs per side.

	Bytes through JSON.parse	Wall time
Before	132.2 MB	525 to 562 ms
After	0	435 to 821 ms

The re-parse is gone. Wall time is within noise at this size, so treat it as a CPU and GC saving.

Review tier: 6/10; how two indexed timestamp columns are written

Two-way door: removing the patch line drops it from the next fork build

Blast radius: created_at and updated_at on stored messages and turn items

Changes made by Claude Opus 5.5 in Claude Code, running in T3 Code.

🤖 Generated with Claude Code

[fireboltdude1357]

Manual review round 1: crev (claude-opus-5-5 + gpt-6.1-sol) (tier 7/10, deep review)

No verified findings.

Reviewed 2 files (+105 -5), 0b0417a5..67c3161e against origin/patch/streamed-write-timestamps.

Tier 7/10 from claude-opus-5-5: Changes how persisted created_at/updated_at index columns are written for every streamed message and turn item; a format mismatch would silently corrupt ordering and pagination data.

Complexity low: Small local swap of three call sites to encode timestamps directly instead of re-parsing payload JSON; the only subtlety is matching the codec to the payload schema.