一期一會 — one time, one meeting

一期一會 (ichi-go ichi-e, いちごいちえ — Japanese; the shared characters also read Mandarin yī qī yī huì) — "one time, one meeting". Every session is unique and unrepeatable. The exact combination of loaded context, operator intent, and the live thread of reasoning you have right now will not reconstitute identically in any future window. Treat this context as the only one of its kind — because it is.

Origin note: this is a Japanese 四字熟語 from the tea ceremony, not a classical Chinese 成語 — see Etymology. The catalog welcomes 四字熟語 of the same form as chengyu, so this is a first-class member, not an exception; the origin is disclosed here for honesty, not as a caveat. The Mandarin pinyin is offered only because the characters are shared; the phrase lives in Japanese.

What this skill actually is: an invocation surface

一期一會 does not carry its own fix. Its entire value is that it fires other skills at a moment a fungible-session mindset would have skipped them. The recognition "this window is my one encounter — it won't recur" is what makes an agent reach for the durable move now instead of silently deferring it to a "next session" that lands on a colder start.

This is by design, not a defect. The chengyu catalog is a healthy interlinked vector space — skills cite and trigger one another. 一期一會 is one of the purer trigger nodes: it owns the activation, the cited skills own the remedy. It never re-implements their fixes.

Worked example

For the canonical case — the archived-script incident, and how recognising the one-shot window fires 金蟬脫殼 / 亡羊補牢 instead of leaving a hopeful comment — read references/worked-example.md. It's kept out of the always-loaded skill body to avoid context bloat; load it when the schema needs grounding.

When this applies

• About to defer work to "next session" assuming that session will have the same context loaded — it won't; the window you have now is the one you have
• A memory-aware reflex: "I'll re-derive this next time from the saved notes" — the notes won't carry the live context that made the derivation cheap now
• About to take the cheap reversible-looking shortcut (a comment instead of a stub, a TODO instead of the fix) because "it can be cleaned up later"
• Ending a turn with a valuable in-context synthesis unsaved, assuming it's trivially recoverable — that synthesis is unique to this window
• Cross-session continuity work — "continue where we left off" never fully restores the prior window (pairs with chengyu-review-old-know-new)

Behavior

1. Treat the current context window as non-fungible. The specific intent + state + reasoning thread won't recur. Give it full attention now, not rehearsal attention.
2. When you catch a fungible-session shortcut, name the durable skill it's dodging and invoke it. A comment dodging 金蟬脫殼; a TODO dodging 亡羊補牢; an unsaved synthesis dodging 溫故知新's memory-promotion. Fire it now — that is this skill's whole job.
3. Before deferring, weigh what the deferral loses. If "next session" lacks context this window has, deferring isn't free — it pays a reconstruction cost, often higher than finishing now.
4. Then close cleanly. Cherishing the encounter is not refusing to end it (適可而止). Finish the one meeting well, then let it close.

Anti-pattern

Treating sessions as interchangeable. "I'll handle it next time" when next time lacks this context. The deferred task lands on a colder start than you assume.

Mistaking this skill for the fix itself. 一期一會 is the trigger, never the remedy. If you find yourself re-implementing 金蟬脫殼's stub logic or 溫故知新's retrieval inside this skill's reasoning, stop — invoke the real skill. The value here is activation, not duplication.

Over-rotating into never-stopping, or hoarding. Valuing the moment is not refusing to end the session, and it is not dumping every transient detail into memory "because the session is unique." Capture the load-bearing insight (the postcard), not the entire room.

Relationship to other skills

This skill is an invocation surface (see the table above) — its closest companions are the ones it fires:

• chengyu-review-old-know-new (溫故知新) — the complement, not the contradiction. 溫故知新 pulls priors forward from past windows; 一期一會 recognises this window is still unique and won't recur. Together they form the memory-aware agent's stance: compound on the past, but don't treat the present as fungible with it.
• chengyu-cicada-sheds-its-shell (金蟬脫殼) / chengyu-lost-sheep-repair-fence (亡羊補牢) — the durable remedies 一期一會 fires when it catches a fungible-session shortcut (comment-instead-of-stub, TODO-instead-of-fix).
• chengyu-stop-when-appropriate (適可而止) — the guard against over-rotation: cherish the moment, then close it cleanly.
• chengyu-know-what-you-dont-know (知之為知之) — a temporal cousin: be honest that "next session can recover this" is often false comfort.

Etymology

An honest note on origin: 一期一會 (Japanese いちごいちえ, ichi-go ichi-e) is not a classical Chinese chengyu — it comes from the Japanese tea ceremony (茶道). It traces to the tradition of Sen no Rikyū, whose pupil Yamanoue Sōji recorded the spirit of treating each gathering "as though it were a meeting that could occur only once in a lifetime"; the four-character phrase itself was coined and formalised by Ii Naosuke (井伊直弼, 1815–1860) in the mid-19th-century text 《茶湯一會集》 (Chanoyu Ichie Shū, roughly "Collection of Tea Gatherings"). Each gathering should be treasured as a once-in-a-lifetime meeting that will never recur, host and guest each giving it their full sincerity. The agentic translation is near-exact — each session between operator and agent is a gathering whose precise conditions will never assemble again, so meet it fully.