# Oh My Pi 17.4.0: model-scoped Tokenizer replaces global token counting (breaking)

> Oh My Pi 17.4.0 removes the global token-counting functions in `@oh-my-pi/pi-agent-core` and replaces them with immutable per-model `Tokenizer` instances, which several context-management functions now require explicitly. On the agent side it adds `/cleanse`, `omp ps`, speculative compaction, and an `extendedContext` setting controlling whether premium long-context windows are used.

| | |
|---|---|
| **Tool** | Oh My Pi |
| **Version** | v17.4.0 |
| **Kind** | release |
| **Published** | 2026-08-20 |
| **Observed** | 2026-08-21 |
| **Significance** | 4/5 |
| **Breaking** | yes |
| **Categories** | breaking, feature, fix, api-change, context-window, pricing, model-support |

## What changed


**Breaking (`@oh-my-pi/pi-agent-core`)**
- `countTokens`, `countTokensConservatively`, `setTokenizerModel`, and `estimateTokens` removed; use model-scoped `agent.tokenizer` with `countTokens(text, mode?)`, `countMessage`, `countMessages`.
- `findCutPoint`, `prepareBranchEntries`, `collectShakeRegions`, `pruneToolOutputs`, `pruneSupersededToolResults`, and `trimRemoteCompactionInputToContextWindow` now require an explicit `Tokenizer`.
- `createCompactionSummaryMessage` takes an options object after `(summary, tokensBefore, timestamp)`.

**Tokenizer / catalog**
- Exact embedded token counting added for Claude, Qwen 3.5+, DeepSeek V3/V4/R1, Kimi K2/K3, and GLM-5+; `Tokenizer` constructs from a resolved catalog `Model`.
- New `Tokenizer.checkTokenBudget(text, budget)` with fast byte-bound pre-check.
- Provider-anchored transcript estimation: `findTranscriptUsageAnchor`, `isTranscriptUsageAnchor`, `estimateTranscriptTokens`.
- Models gain an optional `tokenizer` family field; overridable per model and via `modelOverrides` for proxy models.
- Long-context cost tiers (`cost.longContext`) added to subscription Codex GPT-5.6 models (Sol, Terra, Luna), matching first-party API pricing above 272K input tokens.

**Coding agent**
- `/cleanse` and `omp cleanse` run the checker/repair loop in-session with a live status board.
- `omp ps` interactive monitor for daemon-supervised background processes.
- `extendedContext` setting and `/extended-context` toggle decide whether premium 272K/1M windows are used or the session compacts early to stay on standard pricing.
- Speculative compaction via `compaction.asyncEnabled`; `compaction.methodOrder` replaces `compaction.strategy` / `compaction.remoteEnabled`.
- `/handoff` now compacts in place instead of forking a new session.
- Composer layouts (`composer.shape`), `statusLine.contextLine` gauge, backgroundable Python `eval` cells, revamped todo HUD, compaction divider naming the method and before→after sizes.

**Fixes**
- Tool-argument repair no longer applies lossy transforms when validating `anyOf`/`oneOf` union schemas.
- Reasoning-effort fallback fixed for local OpenAI-compatible servers returning 400 on `chat_template_kwargs.reasoning_effort`; `qwenTemplateReasoningEffort` added for strict local servers.
- DeepSeek-family models on hosts like Fireworks no longer lose reasoning when tools are offered (redundant `tool_choice: "auto"` omitted).
- Fixed tool-call turn failures for `opencode-go/muse-spark-1.2` and related variants.


## Sources

- [github_release](https://github.com/can1357/oh-my-pi/releases/tag/v17.4.0) — retrieved 2026-08-21


## Community

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---
Canonical: https://changelogs.info/oh-my-pi/v17-4-0
Entity: https://changelogs.info/oh-my-pi
Event ID: `evt_2026-08-20_oh-my-pi_v17-4-0`
Licence: event synthesis © changelogs.info, CC BY 4.0. Linked sources belong to their vendors.