Context and Output Compaction

Long conversations and large tool outputs both eat context. Wayland Core handles each with a separate mechanism: automatic context compaction keeps the conversation under the model’s window, and output compaction trims what tool results cost before they enter the context.

Context compaction (automatic)

Context compaction runs on its own in three tiers. You do not call it directly.

Tier	Trigger	Method	LLM call
Microcompact	Too many old tool results, or a long gap	Clears old Read/Bash/Grep/Glob/Write/Edit results, keeping the most recent	No
Autocompact	Input tokens approach the window	The model summarizes the conversation, history is replaced with a boundary marker	Yes
Emergency	Input tokens near the absolute limit	Blocks further calls and asks you to start fresh	No

Defaults live in [compact]. Microcompact keeps the 5 most recent tool results; autocompact triggers around context_window - output_reserve - autocompact_buffer. A circuit breaker stops retrying autocompact after a set number of failures.

[compact]
enabled = true
context_window = 200000
output_reserve = 20000
autocompact_buffer = 13000
emergency_buffer = 3000
micro_keep_recent = 5

Output compaction (you control this)

Output compaction post-processes tool output to cut tokens. Three levels run from lightest to heaviest:

• off: no change.
• safe (default): strip ANSI codes, merge blank lines, collapse carriage-return progress bars.
• full: everything in safe, plus folding repeated lines and compacting JSON indentation.

Set it per run:

wayland-core --compaction full "Run the test suite and report failures"

TOON encoding

With full compaction you can turn on TOON, which encodes uniform JSON arrays as compact tables. It is a session-level choice and cannot change mid-conversation:

wayland-core --compaction full --toon "List the users table as JSON"

[compact]
compaction = "safe"
toon = false

In --json-stream mode a host can change the level at runtime with a set_config command carrying a new compaction value.

Next

• Sessions (save and resume)
• Configuration
• JSON Stream Protocol