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Compress LLM context to save tokens and reduce costs

_{Real session stats: 3,003 compressions · 178,442 tokens saved · 24.7% avg reduction · up to 92% with dedup}

Install · How It Works · Supported Tools · Changelog · Discord

sqz compresses command output before it reaches your LLM. Single Rust binary, zero config.

The real win is dedup: when the same file gets read 5 times in a session, sqz sends it once and returns a 13-token reference for every repeat.

Without sqz:                    With sqz:

File read #1:  2,000 tokens     File read #1:  ~800 tokens (compressed)
File read #2:  2,000 tokens     File read #2:  ~13 tokens  (dedup ref)
File read #3:  2,000 tokens     File read #3:  ~13 tokens  (dedup ref)
───────────────────────         ───────────────────────
Total:         6,000 tokens     Total:         ~826 tokens (86% saved)

Token Savings

24.7% average reduction across 3,003 real compressions · 92% saved on repeated file reads · 86% on shell/git output · 13-token refs for cached content

One developer's week, measured from actual sqz gain output:

$ sqz gain
sqz token savings (last 7 days)
──────────────────────────────────────────────────
  04-13 │                              │   2,329 saved
  04-14 │                              │       0 saved
  04-15 │███                           │  12,954 saved
  04-16 │██                            │   9,223 saved
  04-17 │████                          │  14,752 saved
  04-18 │██████████████████████████████│ 105,569 saved
  04-19 │████████                      │  30,882 saved
  04-20 │█                             │   4,334 saved
──────────────────────────────────────────────────
  Total: 3,003 compressions, 178,442 tokens saved (24.7% avg reduction)

Per-command compression

Single-command compression (measured via cargo test -p sqz-engine benchmarks):

Session-level with dedup

Where the real savings live — the cache sends each file once, repeats cost 13 tokens:

Single-command compression ranges from 2–58% depending on content. Repeated reads drop to 13 tokens each. Your mileage will vary with how repetitive your tool calls are — agentic sessions with many file re-reads see the biggest wins.

Install

Prebuilt binaries (no compiler required — works on every platform):

# macOS / Linux
curl -fsSL https://raw.githubusercontent.com/ojuschugh1/sqz/main/install.sh | sh

# Windows (PowerShell)
irm https://raw.githubusercontent.com/ojuschugh1/sqz/main/install.ps1 | iex

# Any platform via npm
npm install -g sqz-cli

Build from source (cargo install sqz-cli) works too, but needs a C toolchain:

• Linux: build-essential (apt) or equivalent
• macOS: Xcode Command Line Tools (xcode-select --install)
• Windows: Visual Studio Build Tools with the "Desktop development with C++" workload. Without these, cargo install fails with linker link.exe not found. If you don't already have them, use the PowerShell or npm install above instead.

Then initialize:

sqz init --global     # hooks apply to every project on this machine
# or
sqz init              # hooks apply to just this project (.claude/settings.local.json)

--global writes to ~/.claude/settings.json (the user scope per the Anthropic scope table), so the sqz hook fires in every Claude Code session on this machine. This is the common case on first install. Your existing permissions, env, statusLine, and unrelated hooks in ~/.claude/settings.json are preserved — sqz merges its entries rather than overwriting.

Plain sqz init (project scope) is useful when you want sqz active only inside one repo.

Only using one agent? Pass --only (or --skip) to limit which configs are written:

sqz init --only opencode              # just OpenCode, nothing else
sqz init --only opencode,codex        # OpenCode and Codex
sqz init --skip cursor,windsurf       # everything except Cursor and Windsurf

Accepted names: claude, cursor, windsurf, cline, gemini, opencode, codex. Aliases (claude-code, gemini-cli, roo) also work. --only and --skip can't be combined.

That's it. Shell hooks installed, AI tool hooks configured.

How It Works

sqz installs a PreToolUse hook that intercepts bash commands before your AI tool runs them. The output gets compressed transparently — the AI tool never knows.

Claude → git status → [sqz hook rewrites] → compressed output (85% smaller)

What gets compressed:

• Shell output — git, cargo, npm, docker, kubectl, ls, grep, etc.
• JSON — strips nulls, compact encoding
• Logs — collapses repeated lines
• Test output — shows failures only

What doesn't get compressed:

• Stack traces, error messages, secrets — routed to safe mode (0% compression)
• Your prompts and the AI's responses — controlled by the AI tool, not sqz

Supported Tools

CLI

sqz init --global             # Install hooks for every project on this machine
sqz init                      # Install hooks for just this project
sqz init --only opencode      # Only configure OpenCode (skip the rest)
sqz init --skip cursor        # Configure every agent except Cursor
sqz compress <text>           # Compress (or pipe from stdin)
sqz compress --no-cache       # Compress without dedup (always full output)
sqz expand <ref>              # Recover original content from a §ref:HASH§ token
sqz compact                   # Evict stale context to free tokens
sqz gain                      # Show daily token savings
sqz stats                     # Cumulative report
sqz discover                  # Find missed savings
sqz resume                    # Re-inject session context after compaction
sqz hook claude               # Process a PreToolUse hook
sqz proxy --port 8080 # API proxy (compresses full request payloads)

Dedup Escape Hatch

When sqz sees the same content twice, it returns a compact §ref:HASH§ token instead of the full text. Most models handle this fine, but some (e.g., GLM 5.1) can't parse the ref format and loop. Four ways to work around this:

# 1. Recover original content from a ref
sqz expand a1b2c3d4              # prefix match
sqz expand '§ref:a1b2c3d4§'     # paste the whole token

# 2. Compress without dedup (per-invocation)
echo "..." | sqz compress --no-cache

# 3. Disable dedup globally (env var)
export SQZ_NO_DEDUP=1

# 4. MCP passthrough tool (returns input byte-exact, zero transforms)
# Available via tools/list when sqz-mcp is running

Track Your Own Savings

Run sqz gain in your shell any time to see your own daily breakdown (see the Token Savings section above for what the output looks like), and sqz stats for the full cumulative report:

$ sqz stats
┌─────────────────────────┬──────────────────┐
│           sqz compression stats            │
├─────────────────────────┼──────────────────┤
│ Total compressions      │            3,003 │
│ Tokens saved            │          178,442 │
│ Avg reduction           │            24.7% │
│ Cache entries           │               43 │
│ Cache size              │          39.1 KB │
└─────────────────────────┴──────────────────┘

Stats are stored locally in SQLite under ~/.sqz/sessions.db — nothing leaves your machine.

How Compression Works

1. Per-command formatters — git status → compact summary, cargo test → failures only, docker ps → name/image/status table
2. Structural summaries — code files compressed to imports + function signatures + call graph (~70% reduction). The model sees the architecture, not implementation noise.
3. Dedup cache — SHA-256 content hash, persistent across sessions. Second read = 13-token reference.
4. JSON pipeline — strip nulls → project out debug fields → flatten → collapse arrays → TOON encoding (lossless compact format)
5. Safe mode — stack traces, secrets, migrations detected by entropy analysis and routed through with 0% compression

For the full technical details, see docs/.

Configuration

# ~/.sqz/presets/default.toml
[preset]
name = "default"
version = "1.0"

[compression.condense]
enabled = true
max_repeated_lines = 3

[compression.strip_nulls]
enabled = true

[budget]
warning_threshold = 0.70
default_window_size = 200000

Privacy

• Zero telemetry — no data transmitted, no crash reports
• Fully offline — works in air-gapped environments
• All processing local

Development

git clone https://github.com/ojuschugh1/sqz.git
cd sqz
cargo test --workspace
cargo build --release

License

Elastic License 2.0 (ELv2) — use, fork, modify freely. Two restrictions: no competing hosted service, no removing license notices.

Links

• Benchmark: sqz vs rtk
• Discord
• Changelog

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