Conversation Context Mode

Conversation context mode controls how prior turns are accumulated when building multi-turn chat requests. Different dataset formats imply different accumulation strategies, and AIPerf automatically selects the right one based on your data.

Two dimensions determine the mode:

• Turn format: DELTAS (incremental per-turn content) vs MESSAGE_ARRAY (each turn carries its complete message list)
• Response inclusion: WITH_RESPONSES (pre-canned assistant turns in dataset) vs WITHOUT_RESPONSES (only user content; live responses captured at runtime)

Modes

deltas_without_responses

Standard multi-turn chat. Each dataset turn is a user-only delta. AIPerf accumulates turns and threads live inference responses into the history.

Dataset:

Turn 1: {"role": "user", "content": "What is ML?"}
Turn 2: {"role": "user", "content": "Give an example"}
Turn 3: {"role": "user", "content": "How does it differ from traditional programming?"}

Replay:

Request 1: [User "What is ML?"]
  → Server responds with A1
Request 2: [User "What is ML?", Assistant A1, User "Give an example"]
  → Server responds with A2
Request 3: [User "What is ML?", Assistant A1, User "Give an example", Assistant A2, User "How does it differ..."]
  → Server responds with A3

Default for:

• Synthetic datasets
• Multi-turn JSONL
• ShareGPT
• Mooncake traces with hash_ids

deltas_with_responses

Delta-compressed prompts. Each dataset turn only contains the new messages since the previous turn. AIPerf accumulates these deltas to reconstruct the full conversation. The live inference response is only used for measurement and discarded — the pre-canned assistant responses in the dataset are used instead.

Dataset (each turn is a delta):

Turn 1: [{"role": "user", "content": "What is ML?"}]
Turn 2: [{"role": "assistant", "content": "ML is..."}, {"role": "user", "content": "Give an example"}]
Turn 3: [{"role": "assistant", "content": "Sure..."}, {"role": "user", "content": "How does it differ..."}]

Replay (deltas accumulated):

Request 1: [User "What is ML?"]
  → Live response discarded
Request 2: [User "What is ML?"] + [Assistant "ML is...", User "Give an example"]
  → Live response discarded
Request 3: [User "What is ML?"] + [Assistant "ML is...", User "Give an example"] + [Assistant "Sure...", User "How does it differ..."]
  → Live response discarded

Default for:

• N/A (no built-in loader defaults to this mode yet)

message_array_with_responses

Self-contained prompts. Each turn already contains its full context (including assistant responses). No session accumulation.

Dataset:

Turn 1: [{"role": "user", "content": "What is ML?"}]
Turn 2: [{"role": "user", "content": "What is ML?"}, {"role": "assistant", "content": "ML is..."}, {"role": "user", "content": "Give an example"}]
Turn 3: [{"role": "user", "content": "What is ML?"}, {"role": "assistant", "content": "ML is..."}, {"role": "user", "content": "Give an example"}, {"role": "assistant", "content": "Sure..."}, {"role": "user", "content": "How does it differ..."}]

Replay:

Request 1: sends Turn 1 as-is
Request 2: sends Turn 2 as-is
Request 3: sends Turn 3 as-is

Each turn is sent exactly as it appears in the dataset.

Default for:

• Mooncake traces with pre-built messages arrays

message_array_without_responses

Reserved for future use. Each turn would carry a complete user-only message array, requiring live response merging between turns. Not yet implemented.

How It Works

Context mode is resolved through a priority chain:

1. Per-conversation override — A conversation in the dataset can specify its own context_mode
2. Loader default — The dataset loader can declare a default based on dataset format semantics
3. Global fallback — deltas_without_responses

This means most users never need to think about context mode. The loader picks the right default, and individual conversations can override it when needed.