ptk — Python Token Killer
One call. Any Python object. Fewer tokens.
Zero dependencies · Auto type detection · 361 tests

---

Your LLM calls carry dead weight

A typical API response you feed into an agent:

{
  "user": {
    "id": 8821,
    "name": "Alice Chen",
    "email": "alice@example.com",
    "bio": null,
    "avatar_url": null,
    "phone": null,
    "address": null,
    "metadata": {},
    "preferences": {
      "theme": "dark",
      "notifications": null,
      "newsletter": null
    },
    "created_at": "2024-01-15T10:30:00Z",
    "updated_at": "2024-06-20T14:22:00Z",
    "last_login": null,
    "is_verified": true,
    "is_active": true
  },
  "errors": null,
  "warnings": []
}

Seven null fields, two empty containers. Your LLM reads them, bills you for them, learns nothing from them. ptk strips the noise:

import ptk
ptk(response)

{"user":{"id":8821,"name":"Alice Chen","email":"alice@example.com","preferences":{"theme":"dark"},"created_at":"2024-01-15T10:30:00Z","updated_at":"2024-06-20T14:22:00Z","is_verified":true,"is_active":true}}

52% fewer tokens. Same information. No config needed.

pip install python-token-killer
# or
uv add python-token-killer

---

Benchmarks

Token counts via tiktoken (cl100k_base, the tokenizer behind GPT-4 and Claude):

Input                          Tokens (before)   Tokens (after)   Saved
─────────────────────────────────────────────────────────────────────────
API response (JSON)                    1,450              792      45%
Python module (code → sigs)            2,734              309      89%
CI log (58 lines, errors only)         1,389              231      83%
50 user records (tabular)              2,774              922      67%
Verbose prose (text)                     101               74      27%
─────────────────────────────────────────────────────────────────────────
Total                                 11,182            2,627      76%

At Claude Sonnet 4.6 pricing ($3/1M input tokens), a 76% reduction on 100k tokens/day saves ~$6/month per user. Multiply that by your user base and your agent loop iterations.

Run it yourself: python benchmarks/bench.py

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How it works

You pass ptk any Python object. It detects the content type and picks the right compression strategy:

Input	Strategy	Savings
dict / list	Strips null, "", [], {} recursively. Tabular encoding for uniform arrays.	40–70%
Code	Strips comments (preserves # noqa, # type: ignore, TODO). Collapses docstrings. Extracts signatures.	25–89%
Logs	Collapses duplicate lines with counts. Filters to errors and stack traces.	60–90%
Diffs	Folds unchanged context. Strips git noise (index, old mode).	50–75%
Text	Abbreviates verbose words (implementation→impl, configuration→config). Removes filler.	10–30%

---

Usage

import ptk

# ── auto-detected, one call ──────────────────────────────────
ptk.minimize(api_response)        # dict/list → compact JSON, nulls stripped
ptk.minimize(source_code)         # strips comments, collapses docstrings
ptk.minimize(log_output)          # dedup repeated lines, keep errors
ptk.minimize(git_diff)            # fold context, keep changes
ptk.minimize(any_object)          # always returns a string, never raises

# ── aggressive mode: maximum compression ─────────────────────
ptk.minimize(response, aggressive=True)

# ── force content type ───────────────────────────────────────
ptk.minimize(text, content_type="code", mode="signatures")  # sigs only
ptk.minimize(logs, content_type="log", errors_only=True)    # errors only

# ── stats: token counts + savings ────────────────────────────
ptk.stats(response)
# {
#   "output": "...",
#   "original_tokens": 1450,
#   "minimized_tokens": 792,
#   "savings_pct": 45.4,
#   "content_type": "dict"
# }

# ── callable shorthand ───────────────────────────────────────
ptk(response)  # same as ptk.minimize(response)

# ── preserve nulls when they carry meaning ───────────────────
ptk.minimize({"status": "pending", "error": None}, strip_nulls=False)
# → {"status":"pending","error":null}

---

Real-world examples

RAG pipeline: compress retrieved docs before they hit the prompt

Your retriever returns full documents. The LLM needs the content, not the metadata scaffolding around it.

import ptk

def build_context(docs: list[dict]) -> str:
    """Compress retrieved docs before injecting into an LLM prompt."""
    chunks = []
    for doc in docs:
        content = ptk.minimize(doc["content"])   # strip boilerplate
        chunks.append(f"[{doc['source']}]\n{content}")
    return "\n\n---\n\n".join(chunks)

Full working demo with token counts: examples/rag_pipeline.py

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LangGraph / LangChain: compress tool outputs between nodes

Drop this node between a tool call and the next LLM call. Tool outputs shrink before they re-enter the context window.

import ptk

def compress_tool_output(state: dict) -> dict:
    """Compress the last tool message before the next LLM call."""
    state["messages"][-1]["content"] = ptk.minimize(
        state["messages"][-1]["content"], aggressive=True
    )
    return state

Complete agent loop with per-step token savings: examples/langgraph_agent.py

---

Log triage: feed only failures to your LLM

A 10,000-line CI log collapses to the failures and their stack traces.

import ptk

errors = ptk.minimize(ci_log, content_type="log", aggressive=True)
# 80%+ fewer tokens, same diagnostic signal.

Before/after demo: examples/log_triage.py

---

API reference

ptk.minimize(obj, *, aggressive=False, content_type=None, **kw) → str

• aggressive=True maximizes compression: timestamps stripped, signatures-only for code, errors-only for logs
• content_type overrides auto-detection: "dict", "list", "code", "log", "diff", "text"
• format controls dict output: "json" (default), "kv", "tabular"
• mode controls code output: "clean" (default) or "signatures"
• errors_only filters logs to errors and stack traces

ptk.stats(obj, **kw) → dict

Same interface as minimize. Returns output, original_tokens, minimized_tokens, savings_pct, content_type.

ptk(obj) callable shorthand

The module itself is callable. ptk(x) equals ptk.minimize(x).

---

Comparison

Tool	Type	Tradeoff
ptk	Python library	One call, any Python object, zero deps
RTK	Rust CLI	Compresses shell command output for coding agents
claw-compactor	Python library	14-stage AST-aware pipeline, heavier setup
LLMLingua	Python library	Neural compression, requires GPU

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Design

• Zero required dependencies. Stdlib only. tiktoken is optional for exact token counts.
• Never raises. Any Python object produces a string. Circular refs, bytes, nan, generators all handled.
• Never mutates. Your input stays untouched.
• Thread-safe. Stateless singleton minimizers.
• Fast. Precompiled regexes, frozenset lookups, single-pass algorithms. Microseconds per call.

---

Development

git clone https://github.com/amahi2001/python-token-killer.git
cd python-token-killer
uv sync          # installs all dev dependencies, creates .venv automatically
make check       # lint + typecheck + 361 tests

License

MIT