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deepseek-harness/packages/llm/llm/src/index.ts
T

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TypeScript

/**
* LLM service: adapter registry with a waterfall-interceptable streaming call
* surface. Exports the `LlmService` default, the abstract `LlmAdapter` for
* provider backends, and `BlockAssembler` for chunk assembly.
*
* @module @deepseek-ai/dsh-llm
*/
import { Context, Service } from 'cordis'
import type { GenerateOptions, StreamChunk } from './types.ts'
import { HarnessError } from './error.ts'
export * from './attribution.ts'
export * from './brand.ts'
export * from './never.ts'
export * from './error.ts'
export * from './types.ts'
export { BlockAssembler } from './assembler.ts'
export { callConfigEquals, deepFreeze } from './call-config.ts'
export type { LlmCallConfig } from './call-config.ts'
declare module 'cordis' {
interface Context {
llm: LlmService
}
interface Events {
/**
* Waterfall around every streaming model call (retry, replay, routing).
* Bound to the {@link LlmService}; call `next()` to reach the resolved
* adapter's stream, or yield your own chunks to short-circuit.
* @param options - the full request. A LOOP-built request arrives
* deep-frozen (mutation throws): its content is a pure function of the
* session log (the reconstructability RFC), so listeners read it, never
* rewrite it. A hand-built one-shot (compaction summarize) is the
* caller's own object and stays mutable here.
* @mode waterfall
*/
'llm/stream'(this: LlmService, options: GenerateOptions, next: () => AsyncIterable<StreamChunk>): AsyncIterable<StreamChunk>
}
}
/**
* Typed error for LLM-related failures. Extends {@link HarnessError}, so the
* `code` string (e.g. `AUTH`, `RATE_LIMIT`, `NO_ADAPTER`) is shared taxonomy;
* `status` carries the HTTP status when the error originated from a non-2xx
* provider response (absent for protocol/usage errors that have no HTTP status).
*/
export class LlmError extends HarnessError {
constructor(message: string, code: string, public status?: number, options?: ErrorOptions) {
super(message, code, options)
this.name = 'LlmError'
}
}
/**
* Provider-wire adapter for the harness message and stream vocabulary. Register implementations
* with `ctx.llm.registerAdapter(models, adapter)`. Every provider HTTP request must include
* `attributionHeaders()`; prove that at the wire or library header-hook boundary. The hand-rolled
* DeepSeek and pi-ai adapters intentionally exercise this contract through different internals.
*/
export abstract class LlmAdapter {
/**
* Stream one model call as raw chunks. The only required method.
* @param options - the fully-assembled request; implementations must honor `options.signal`.
* @returns the chunk stream, obeying the adapter contract documented on `StreamChunk`.
*/
abstract stream(options: GenerateOptions): AsyncIterable<StreamChunk>
}
/**
* The abstract `llm` service: an adapter registry plus a streaming model-call
* surface, interceptable via the `llm/stream` waterfall.
*/
export class LlmService extends Service {
private adapters = new Map<string, LlmAdapter>()
constructor(ctx: Context) {
super(ctx, 'llm')
}
/**
* Register an adapter for the given model names. Throws `LlmError` with code
* `DUPLICATE_ADAPTER` if any model already has an adapter (all-or-nothing).
* Disposed with the fiber.
* @param models - every model name this adapter should serve.
* @param adapter - the adapter that streams calls for those models.
* @returns the disposer that unregisters all of them.
*/
registerAdapter(models: string[], adapter: LlmAdapter): () => void {
const dispose = this.ctx.effect(function* (this: LlmService) {
for (const model of models) {
if (this.adapters.has(model)) {
throw new LlmError(`an adapter for model "${model}" is already registered`, 'DUPLICATE_ADAPTER')
}
}
for (const model of models) this.adapters.set(model, adapter)
yield () => {
for (const model of models) this.adapters.delete(model)
}
}.bind(this), 'llm.registerAdapter()')
// ctx.effect's disposer returns Promise<void>; our disposer API is
// synchronous fire-and-forget — discard the (always-resolved) promise.
return () => void dispose()
}
/**
* Model names with a registered adapter.
* @returns the registered names, in registration order.
*/
models(): string[] {
return [...this.adapters.keys()]
}
private adapter(model: string): LlmAdapter {
const adapter = this.adapters.get(model)
if (!adapter) throw new LlmError(`no adapter registered for model "${model}"`, 'NO_ADAPTER')
return adapter
}
/**
* Stream one model call as raw chunks (token-level deltas). Throws
* `LlmError` with code `NO_ADAPTER` if no adapter is registered for
* `options.model`. Dispatches through the `llm/stream` waterfall.
* @param options - the full request; `options.model` selects the adapter.
* @returns the chunk stream, possibly wrapped by `llm/stream` listeners.
*/
stream(options: GenerateOptions): AsyncIterable<StreamChunk> {
return this.ctx.waterfall(this, 'llm/stream', options, () => {
return this.adapter(options.model).stream(options)
})
}
}
export default LlmService