---
url: >-
  https://adk.nht.io/api/@nhtio/adk/batteries/context/thrift/subtractive_pass/variables/DEFAULT_ENCODING.md
description: 'The token encoding this battery measures under, by default.'
---

# Variable: DEFAULT\_ENCODING

```ts
const DEFAULT_ENCODING: "cl100k_base" = "cl100k_base";
```

Defined in: [src/batteries/context/thrift/subtractive\_pass.ts:74](https://github.com/NHTIO/ADK/blob/v1.20260713.1/src/src/batteries/context/thrift/subtractive_pass.ts#L74)

The token encoding this battery measures under, by default.

## Remarks

`'cl100k_base'` — a widely-available, model-agnostic tiktoken encoding — is the default because
this battery is core-agnostic: unlike the flagship reference agent it was extracted from (which
hard-codes the `gemma` encoding because its engine IS Gemma via LiteRT-LM), this battery has no
opinion on which model you run. `cl100k_base` is a reasonable, broadly-supported baseline for a
caller who hasn't thought about encodings yet; a caller running Gemma, Claude, or any other model
with a distinct tokenizer should pass their own `encoding` (and a matching [EstimateTokensFn](../../contracts/type-aliases/EstimateTokensFn.md))
so the budget math agrees with what their model/battery actually counts. The encoding identifier is
an opaque string as far as this module is concerned — it is never validated or interpreted here,
only threaded through to the injected [EstimateTokensFn](../../contracts/type-aliases/EstimateTokensFn.md).