diff --git a/legacy/src/llms/chat.ts b/legacy/src/llms/chat.ts
index 1bfe7097..3583b0a7 100644
--- a/legacy/src/llms/chat.ts
+++ b/legacy/src/llms/chat.ts
@@ -7,122 +7,14 @@ import { printNode, zodToTs } from 'zod-to-ts'
 
 import * as errors from '@/errors'
 import * as types from '@/types'
-import { BaseTask } from '@/task'
 import { getCompiledTemplate } from '@/template'
-import {
-  Tokenizer,
-  getModelNameForTiktoken,
-  getTokenizerForModel
-} from '@/tokenizer'
+import { getModelNameForTiktoken } from '@/tokenizer'
 import {
   extractJSONArrayFromString,
   extractJSONObjectFromString
 } from '@/utils'
 
-// TODO: TInput should only be allowed to be void or an object
-export abstract class BaseLLM<
-  TInput = void,
-  TOutput = string,
-  TModelParams extends Record<string, any> = Record<string, any>
-> extends BaseTask<TInput, TOutput> {
-  protected _inputSchema: ZodType<TInput> | undefined
-  protected _outputSchema: ZodType<TOutput> | undefined
-
-  protected _provider: string
-  protected _model: string
-  protected _modelParams: TModelParams | undefined
-  protected _examples: types.LLMExample[] | undefined
-  protected _tokenizerP?: Promise<Tokenizer | null>
-
-  constructor(
-    options: SetRequired<
-      types.BaseLLMOptions<TInput, TOutput, TModelParams>,
-      'provider' | 'model'
-    >
-  ) {
-    super(options)
-
-    this._inputSchema = options.inputSchema
-    this._outputSchema = options.outputSchema
-
-    this._provider = options.provider
-    this._model = options.model
-    this._modelParams = options.modelParams
-    this._examples = options.examples
-  }
-
-  // TODO: use polymorphic `this` type to return correct BaseLLM subclass type
-  input<U>(inputSchema: ZodType<U>): BaseLLM<U, TOutput, TModelParams> {
-    const refinedInstance = this as unknown as BaseLLM<U, TOutput, TModelParams>
-    refinedInstance._inputSchema = inputSchema
-    return refinedInstance
-  }
-
-  // TODO: use polymorphic `this` type to return correct BaseLLM subclass type
-  output<U>(outputSchema: ZodType<U>): BaseLLM<TInput, U, TModelParams> {
-    const refinedInstance = this as unknown as BaseLLM<TInput, U, TModelParams>
-    refinedInstance._outputSchema = outputSchema
-    return refinedInstance
-  }
-
-  public override get inputSchema(): ZodType<TInput> {
-    if (this._inputSchema) {
-      return this._inputSchema
-    } else {
-      // TODO: improve typing
-      return z.void() as unknown as ZodType<TInput>
-    }
-  }
-
-  public override get outputSchema(): ZodType<TOutput> {
-    if (this._outputSchema) {
-      return this._outputSchema
-    } else {
-      // TODO: improve typing
-      return z.string() as unknown as ZodType<TOutput>
-    }
-  }
-
-  public override get name(): string {
-    return `${this._provider}:chat:${this._model}`
-  }
-
-  examples(examples: types.LLMExample[]): this {
-    this._examples = examples
-    return this
-  }
-
-  modelParams(params: Partial<TModelParams>): this {
-    // We assume that modelParams does not include nested objects.
-    // If it did, we would need to do a deep merge.
-    this._modelParams = { ...this._modelParams, ...params } as TModelParams
-    return this
-  }
-
-  public async getNumTokens(text: string): Promise<number> {
-    if (!this._tokenizerP) {
-      const model = this._model || 'gpt2'
-
-      this._tokenizerP = getTokenizerForModel(model).catch((err) => {
-        console.warn(
-          `Failed to initialize tokenizer for model "${model}", falling back to approximate count`,
-          err
-        )
-
-        return null
-      })
-    }
-
-    const tokenizer = await this._tokenizerP
-
-    if (tokenizer) {
-      return tokenizer.encode(text).length
-    }
-
-    // fallback to approximate calculation if tokenizer is not available
-    return Math.ceil(text.length / 4)
-  }
-}
+import { BaseLLM } from './llm'
 
 export abstract class BaseChatModel<
   TInput = void,