--- url: >- https://adk.nht.io/api/@nhtio/adk/batteries/interfaces/PromptAssembledObservation.md description: >- One observation of the fully-assembled request a battery is about to send TO the model, fired the instant assembly completes and BEFORE the engine/HTTP dispatch. It is the mirror of [`RawGenerationObservation`](https://adk.nht.io/api/@nhtio/adk/batteries/interfaces/RawGenerationObservation): that seam exposes the raw text coming back FROM the model; this one exposes the raw request going TO it. Together they let you read ground truth at both ends of the wire — e.g. to settle whether a "smart quote" in a rendered answer came from the model itself or from a downstream markdown renderer, you inspect the bytes here, not the DOM. --- # Interface: PromptAssembledObservation Defined in: [src/batteries/llm/chat\_common/types.ts:399](https://github.com/NHTIO/ADK/blob/v1.20260713.1/src/src/batteries/llm/chat_common/types.ts#L399) One observation of the fully-assembled request a battery is about to send TO the model, fired the instant assembly completes and BEFORE the engine/HTTP dispatch. It is the mirror of [RawGenerationObservation](RawGenerationObservation.md): that seam exposes the raw text coming back FROM the model; this one exposes the raw request going TO it. Together they let you read ground truth at both ends of the wire — e.g. to settle whether a "smart quote" in a rendered answer came from the model itself or from a downstream markdown renderer, you inspect the bytes here, not the DOM. ## Remarks This is a pure observability tap — it returns `void`, never mutates the request, and never throws into the generation path (the adapter swallows callback errors). It fires once per terminal generation (one per non-streamed turn; one per stream, at dispatch), across ALL five LLM batteries. **Handed back AS-IS — no redaction.** The observation carries the request exactly as assembled. The ADK does not scrub credentials, headers, or any other field for you: what you put on the request is what you see here, and if you route this to a persistent sink (a log, `localStorage`, a file) you may persist secrets that rode the request (an `apiKey`, `Authorization` header, etc.). That is your responsibility to handle, not the battery's — the ADK surfaces the truth and lets you decide what to do with it. (In practice the API batteries strip ADK-control keys like `apiKey` out of the wire body before this fires, but that is incidental to how the body is built, not a guarantee.) ## Properties | Property | Type | Description | Defined in | | ------------------------------------------------ | --------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------- | | `battery` | `string` | Which battery assembled this request (e.g. `'litert_lm'`, `'openai_chat_completions'`). | [src/batteries/llm/chat\_common/types.ts:401](https://github.com/NHTIO/ADK/blob/v1.20260713.1/src/src/batteries/llm/chat_common/types.ts#L401) | | `kind` | `"rendered-prompt"` | `"request-body"` | The shape of the assembled request. `'rendered-prompt'` for the on-device batteries (transformers.js, LiteRT-LM), which render a preface string + a messages array for the engine; `'request-body'` for the API batteries (OpenAI-compatible, Ollama, WebLLM), which POST a JSON body. | [src/batteries/llm/chat\_common/types.ts:407](https://github.com/NHTIO/ADK/blob/v1.20260713.1/src/src/batteries/llm/chat_common/types.ts#L407) | | `messages` | `unknown` | The per-turn messages exactly as handed to the engine (on-device) or placed on the wire (API): the engine's message array, or the request body's `messages`. | [src/batteries/llm/chat\_common/types.ts:418](https://github.com/NHTIO/ADK/blob/v1.20260713.1/src/src/batteries/llm/chat_common/types.ts#L418) | | `preface?` | `unknown` | On-device leading/system content rendered ahead of the timeline (e.g. the LiteRT `preface` object, which carries the assembled system message text and — for native tool delivery — the tool list), when applicable. Its concrete shape is battery-specific; captured verbatim. Absent for the API batteries. | [src/batteries/llm/chat\_common/types.ts:413](https://github.com/NHTIO/ADK/blob/v1.20260713.1/src/src/batteries/llm/chat_common/types.ts#L413) | | `requestBody?` | `unknown` | API batteries only: the complete assembled request body, exactly as it will be sent (see the AS-IS / no-redaction note above). Absent for the on-device batteries. | [src/batteries/llm/chat\_common/types.ts:428](https://github.com/NHTIO/ADK/blob/v1.20260713.1/src/src/batteries/llm/chat_common/types.ts#L428) | | `streamed` | `boolean` | Whether this generation streams its response (vs. a single batch call). | [src/batteries/llm/chat\_common/types.ts:430](https://github.com/NHTIO/ADK/blob/v1.20260713.1/src/src/batteries/llm/chat_common/types.ts#L430) | | `streamId` | `string` | The adapter's stream/message id for this generation, for correlating with other telemetry. | [src/batteries/llm/chat\_common/types.ts:432](https://github.com/NHTIO/ADK/blob/v1.20260713.1/src/src/batteries/llm/chat_common/types.ts#L432) | | `tools?` | `unknown` | The tool declarations exactly as dispatched: the rendered `` prompt text (on-device prompt-delivery) or the wire `tools` array (API / native tool delivery). Absent when no tools are sent. | [src/batteries/llm/chat\_common/types.ts:423](https://github.com/NHTIO/ADK/blob/v1.20260713.1/src/src/batteries/llm/chat_common/types.ts#L423) |