API revision history

arcdps has no versioned API — the contract is “whatever the current DLL does,” updated in step with game builds. That makes the changelog on the official site (https://www.deltaconnected.com/arcdps/, fetched 2026-08-08) the only record of when the API and EVTC format changed shape. This page collects the entries that matter to extension authors and log-parser maintainers, quoted verbatim (grouping and emphasis ours). The current release at fetch time was 1.2026.718.905.

Update cadence context, from the same page: “some client updates may change components used by arcdps, requiring an arcdps update,” and “most errors will disable logging and extension data sharing features” — i.e. after a game patch, a stale arcdps usually degrades gracefully rather than crashing.

may.07.2026 — the big restructuring

The most consequential recent batch for anyone with pre-2026 code or docs:

updated imgui, all addons will need to be updated manually or through their updater

evtc: animation events moved to CBTS_ANIMATIONSTART and CBTS_ANIMATIONSTOP rather than inferred.

evtc: buff apply and remove events moved to CBTS_BUFFAPPLY, CBTS_BUFFCHANGE, CBTS_BUFFREMOVE_SINGLE, CBTS_BUFFREMOVE_ALL rather than inferred.

evtc: merged cbtbuffcycle into cbtresult.

api: updated to imgui 1.92.7.

api: replaced directx version with imguiversion in get_init_addr.

defuncd CBTS_APIDELAYED.

Impact: older third-party documentation (and many bindings) describe skill activations and buff applies/removes as plain CBTS_COMBAT-family events discriminated by is_activation/is_buffremove — that describes pre-may-2026 behavior. Current events are explicit statechanges (67–72). The old cbtbuffcycle enum’s values now live at the tail of cbtresult (CBTR_BUFF_DAMAGE*, values 14–18). The last get_init_addr parameter changed meaning from a DirectX version to IMGUI_VERSION_NUMBER, and the ImGui bump means imguivers must now be 19270.

jun.02.2026 — unload contract hardened

api: enforce presence of get_release_addr export.

api: allow extensions to refuse unload by returning 0 in get_release_addr.

api: get_release_addr will get u32 reason of removal in parameter 1.

evtc: added CBTS_STEALTHCHANGE/GADGETANIMATION/GADGETNAME

Impact: get_release_addr went from a zero-argument formality to void* get_release_addr(uint32_t reason) with veto power. Extensions without the export no longer load (ARCDPSEXTENLOAD_MISSING_GET_RELEASE_ADDR).

jul.01.2026 — evtc event batch

evtc: added CBTS_MISSILEEFFECT.

evtc: added CBTS_GADGETCAPTURECREATE / GADGETCAPTUREPROGRESS / GADGETCAPTUREREMOVE / GADGETCAPTUREOUTLINEPOINT.

evtc: retired CBTS_RATEHEALTH, added CBTS_TICK.

evtc: removed hitbox height from evtc_agent (defunc, wasnt hitbox height).

Impact: the final uint16_t of evtc_agent is now named defunc; tick-rate monitoring moved from CBTS_RATEHEALTH to CBTS_TICK.

Older retirements still visible in the enum

The _DEFUNC entries in cbtstatechange carry their own retirement dates in the source: CBTS_EFFECT1_DEFUNC (since 230716+), CBTS_LAST90BEFOREDOWN_DEFUNC (since 240529+), CBTS_EFFECT2_DEFUNC (since 250526+), CBTS_STATRESET_DEFUNC (since 260402+), CBTS_APIDELAYED_DEFUNC (since 260501+), CBTS_RATEHEALTH (since 260627+). Old logs may still contain them; current builds don’t emit them.

Similarly, the EVTC cbtevent revision byte (header[12]) records the one historical struct-layout break — see revision notes.

Practical advice

Pin your docs reading to a date: anything describing activation/buff events as is_activation/is_buffremove flags on combat events, a directx version parameter, or an optional get_release_addr predates mid-2026.
Parsers should key behavior off the header build date (bytes 4–11 of the EVTC header) — that’s what Elite Insights does for build-dependent semantics like buff-formula attributes.
One community-recorded bad build worth knowing: arcdps 20250420 had broken team-change-on-despawn events; at least one WvW tool special-cases logs from that build.