Agent Sessions
The Rollout
Notes from building Agent Sessions: usage math, local agent-session formats, and what shipped.
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How coding agents remember: a field study of six session-history formats
Six coding agents on one Mac wrote 3,096 session transcripts over eleven months. We parsed all of them and measured what each format actually records: how many bytes it takes to remember one human sentence, which agents know what they cost, why most reasoning is now sealed even on your own disk, and which format can actually find anything again. With a feature scorecard and concrete recommendations for each vendor.
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Where AI coding agents store your session history: the real paths and formats
Every coding agent writes a full transcript of each session to a local file, but no two agree on where it goes or what format it takes. This is a grounded tour of the actual paths and formats — Claude Code's per-project JSONL, Codex's date-sharded rollout files under ~/.codex/sessions, OpenCode's SQLite database, Cursor's two-store split, and a few others — with the parsing gotchas that bite when you try to read them yourself.
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Projecting the Claude 5-hour limit: burn rate, not percent used
A usage percentage like "7% used" is a level, not a rate: it cannot tell you whether you will reach the reset before the rolling window fills. This is the burn-rate math behind Agent Sessions' Session Runway — how per-session token logs become a quota-minutes-per-hour rate, how run-out gets projected, and why the Claude side stays honest about being coarse by design.