TokenPak v1.21.0

This backward-compatible minor release adds facts-only request timing and live in-flight visibility, plus an optional client-return session-economics decoration. It also corrects forecast calibration, downstream-disconnect accounting, and release-gate schema capture.

Added

• The proxy records each request's UTC start time, time to first upstream byte, and stream duration in additive nullable monitor columns. Cleartext SSE responses also expose their latest provider-reported output-token count while the request is active. An auth-gated, read-only GET /inflight endpoint reports these facts and any projection already computed at admission; it does not calculate an ETA or mutate accounting state.
• An opt-in, default-off session-economics decoration can append the existing one-line rendering to the client copy of an eligible non-streaming response. A versioned marker is removed from echoed assistant history before replay, while provider bytes and accounting inputs continue to use undecorated content.

Fixed

• Session-forecast calibration now validates that coverage targets match the statistic actually measured, includes per-turn cost shape in readiness cache keys, and reads ledger fingerprints and scoring corpora from one consistent transaction.
• Downstream BrokenPipeError and ConnectionResetError outcomes are recorded as client disconnects instead of synthetic HTTP 502 or provider failures. Genuine upstream and internal errors retain their existing failure path.
• The release-gate SQLite schema generator now materializes clean telemetry, Spend Guard, and proxy monitor stores in an isolated temporary directory. Snapshot generation no longer reads ambient user databases, and the monitor schema is included in drift detection.
• The legacy stats snapshot now writes to TokenPak's product-owned vault state directory instead of a retired private vault layout.
• Public API snapshot generation now excludes two optional third-party aliases in both installed-extra and dependency-absent environments, preventing environment-dependent phantom exports without changing TokenPak's API.

Upgrade

python -m pip install --upgrade "tokenpak==1.21.0"

No manual configuration migration is required. Existing proxy monitor stores gain nullable timing columns through the additive migration. The optional client-return decoration remains disabled unless explicitly enabled.

Rollback

python -m pip install --upgrade "tokenpak==1.20.0"

The release introduces no destructive state migration. Existing readers remain compatible with the additive nullable monitor columns.

Compatibility

• The public API snapshot contains 4,697 symbols: 18 additive exports and zero removals relative to v1.20.0. The additions comprise the in-flight endpoint builder, six in-flight registry functions, ten session-economics decoration exports, and IncrementalUsageTracker.
• Live mid-stream output usage is available for cleartext SSE. Compressed SSE retains its existing persisted end-of-stream usage path but does not expose a live incremental count.
• No existing public symbol is removed or reclassified. No breaking changes or deprecations are introduced.