Open source library

Polar Llama

A Python library for parallel LLM inference across providers, built on Polars DataFrames.

v0.8.0Released July 14, 2026
View on GitHubPyPI package
Version0.9.0latest0.8.30.8.20.8.10.8.00.7.30.7.20.7.10.7.00.6.30.6.20.6.10.6.00.5.30.5.20.5.10.5.00.3.00.2.20.2.10.2.00.1.7
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Overview

Polar Llama is a Python library that enables parallel inference calls to multiple Large Language Model providers through Polars dataframes. It streamlines batch processing of AI queries without serial request delays, making it ideal for data-intensive AI applications. 0.8.0 adds a persistent, incrementally updatable HNSW index that you build once, update in place, and save to disk.

Concurrent Processing

Send multiple inference requests in parallel without waiting for individual completions

🔌Six Providers

OpenAI, Anthropic, Gemini, Groq, AWS Bedrock, and on-device MLX (Apple Silicon)

🧭Vector Search

Embeddings (hosted or offline), similarity metrics, stateless knn_hnsw, and a persistent, updatable HnswIndex

🔬Research Workflows

Qualitative and survey research tooling: codebook induction, inter-rater reliability, survey quality flags, human-in-the-loop review

Installation

Using pip

bash
pip install polar-llama==0.8.0

On-device inference (Apple Silicon)

Pulls in mlx and mlx-lm; requires an Apple Silicon Mac and Python ≥ 3.10

bash
pip install "polar-llama[local]"

Excel review exports

Only needed for export_review_sample(..., format="xlsx"); CSV needs nothing extra

bash
pip install "polar-llama[excel]"

Development Installation

bash
maturin develop

Quick Start

Get started with a simple example

python
import polars as pl
from polar_llama import Provider
import dotenv

dotenv.load_dotenv()

# Example questions
questions = [
    'What is the capital of France?',
    'What is the difference between polars and pandas?'
]

df = pl.DataFrame({'Questions': questions})

# Using the fluent .llama namespace (recommended)
df = df.with_columns(
    answer=pl.col('Questions').llama.inference_async(
        provider=Provider.OPENAI,
        model='gpt-4o-mini'
    )
)

What’s New in 0.8.0

New in 0.8.0

Persistent HNSW Index

HnswIndex: build once, add and remove incrementally, save and load (#82)

knn_hnsw is stateless: every call rebuilds the HNSW graph from the corpus you pass it. HnswIndex is a persistent, incrementally updatable index. Build it once, .add() / .remove() points, .query() it as often as you like, and .save() / HnswIndex.load() it to and from disk. Like Checkpoint and Codebook, it is a DataFrame-native stateful object rather than an expression.

python
import polars as pl
from polar_llama import HnswIndex, embedding_async, Provider

corpus = pl.DataFrame({
    "doc_id": ["doc-1", "doc-2", "doc-3", "doc-4"],
    "text": ["AI research", "cooking tips", "machine learning", "recipes"],
}).with_columns(
    embedding=embedding_async(pl.col("text"), provider=Provider.OPENAI)
)

# Build once.
index = HnswIndex.build(corpus, id_col="doc_id", embedding_col="embedding")

# Query as many times as you like, with no rebuild.
queries = pl.DataFrame({"q": ["artificial intelligence"]}).with_columns(
    embedding=embedding_async(pl.col("q"), provider=Provider.OPENAI)
)
results = index.query(queries, embedding_col="embedding", k=2)
# query_id | neighbor_id | distance | rank

# Grow incrementally (queryable immediately) and soft-delete.
index.add(new_docs, id_col="doc_id", embedding_col="embedding")
index.remove(["doc-2"])

# Persist and reload, including pending staging/tombstone state.
index.save("my_index.bin")
index = HnswIndex.load("my_index.bin")

# Or use it inside a lazy pipeline as an expression
queries.with_columns(
    neighbors=index.knn(pl.col("embedding"), k=5)   # List[Struct{neighbor_id, distance, rank}]
).explode("neighbors").unnest("neighbors")
MemberPurpose
HnswIndex.build(df, id_col, embedding_col, *, ef_construction, ef_search, seed, auto_compact, compact_*_min, compact_*_ratio)Build a fresh index from a DataFrame
index.add(df, id_col, embedding_col) / index.remove(ids)Upsert into the staging buffer / soft-delete by id; each returns the number of rows affected
index.query(query_df, embedding_col, k) / index.query_one(vector, k)Batch or single-vector search; query_id is the query row's 0-based index
index.knn(expr, k)The same batch core as a map_batches expression
index.compact() / index.should_compact / index.auto_compactForce a rebuild, check thresholds, or toggle automatic compaction
index.save(path) / HnswIndex.load(path)Round-trip the whole index through a bincode file
len(index), index.dim, "id" in index, index.staged_len, index.tombstone_lenIntrospection

Updates on an Immutable Graph

A staging buffer, tombstones, and compaction over instant-distance's HnswMap

instant-distance’s HnswMap can’t be modified once built, so HnswIndex adds a small LSM-like layer on top. .add() upserts into a brute-force staging buffer that is queryable immediately. .remove() soft-deletes through a tombstone set. Queries over-fetch from the main graph (k' = min(k + tombstone_count, ef_search)) so removals don’t shrink your result count. Compaction rebuilds the graph from every live point and clears staging and tombstones. It runs automatically (auto_compact=True, the default) once either crosses max(threshold_min, threshold_ratio * len(index)), or on demand via .compact().

knn_hnswHnswIndex
CorpusRebuilt every callBuilt once, updated incrementally
StateNone (pure expression)Stateful object (build/add/remove/save/load)
Best forA one-off query against a corpus already in memoryA corpus you query repeatedly, or that grows over time
PersistenceNone.save() / .load()

Performance: single-digit-millisecond queries at 100k points after compaction, and loading a 100k-point index is a low-single-digit-second bincode deserialization. There is no mmap or lazy-load path, so .load() always deserializes the full graph into memory. External ids are arbitrary strings mapped to a stable internal id space that survives compaction. bincode is the only new Rust dependency, and knn_hnsw is untouched.

Everything Since 0.2.2

0.8.0 is cumulative: every feature shipped in 0.2.2 is still here, plus everything added across 0.3.0, 0.5.0, 0.5.1, 0.5.2, 0.5.3, 0.6.0, 0.6.1, 0.6.2, 0.6.3, 0.7.0, 0.7.1, 0.7.2, 0.7.3.

0.3.0 – 0.5.2: Tool Use, Prompt Optimization, Caching, Local MLX

Released 2026-06-10 to 2026-07-12

🧰Tool Use / MCP

tools_to_response_model, mcp_tools, execute_tool_calls, tool_results_to_message: batch-parallel tool calling over an MCP server or a Python executor (0.3.0)

🗄️Provider-Native Prompt Caching

cache=True / CacheConfig shares a cached system prefix across rows via Anthropic cache_control, with 5-minute and 1-hour TTLs (0.3.0)

🎛️Prompt Optimization Engine

Signature, Predict, evaluate, BootstrapFewShot, InstructionOptimizer: DSPy-style instruction and few-shot tuning (0.3.0)

🍎Local MLX Backend

inference_local with server and in_process engines, collapsed prefix prefill, batched quantized KV cache (0.5.0), and an on-device prompt-tuning bridge (0.5.1)

Along the way: updated default models for every provider, OPENAI_BASE_URL / ANTHROPIC_BASE_URL overrides and POLAR_LLAMA_MAX_CONCURRENCY (0.3.0), and fixes for in-process Gemma 3n inference (0.5.2). See the 0.5.2 docs for the full details.

0.5.3: Strict-Mode Taxonomy Fix

Released 2026-07-13

tag_taxonomy() works on OpenAI strict mode again. The per-field thinking reasoning is now List[{value, reasoning}] instead of a dict keyed by value name, and $ref sibling keywords are stripped from generated schemas (#51). A new warning flags Dict-typed fields in user-supplied response models.

0.6.x: Production Runs

Streaming, checkpointing, usage accounting, and response caching. Released 2026-07-13 to 2026-07-14

ReleaseFeatureWhat shipped
0.6.0Streaminginference_stream() with an on_token(row_index, delta) callback and a Struct{text, finished} column; native SSE for OpenAI, Groq, Anthropic; GROQ_BASE_URL override
0.6.1Checkpointingcheckpoint="path" / Checkpoint(...) on inference_async and inference_messages: resumable runs over a crash-durable Parquet store keyed by content + config hash
0.6.2Usage & costusage=True returns Struct{response, usage{input_tokens, output_tokens, cached_tokens, latency_ms, cost_usd}} from an overridable price table (price_table=, register_model_price)
0.6.3Dedupe & response cachededupe=True collapses duplicate rows in-run; response_cache= / ResponseCache(path, ttl=...) reuses results across jobs; DedupeStats reports hits and calls

0.7.x: Research Workflows

Codebook induction, agreement metrics, survey quality flags, and human review. Released 2026-07-14

ReleaseFeatureWhat shipped
0.7.0Codebook inductioncluster_embeddings (hand-rolled spherical k-means in Rust), induce_codebook, apply_codebook, codebook_to_taxonomy
0.7.1Inter-rater reliabilitycohens_kappa and krippendorffs_alpha as aggregation expressions, bit-for-bit with sklearn / krippendorff, with bootstrap CIs
0.7.2Survey quality flagsquality_report / QualityConfig: straightlining, gibberish, duplicate-answer, length-outlier and speeder scores, plus an opt-in near-duplicate / likely-AI tier
0.7.3Human-in-the-loop reviewexport_review_sample, import_corrections (with kappa), corrections_to_trainset, retune_from_corrections; optional [excel] extra

Examples & Cookbooks

Tool Use: Emit, Execute, Synthesize

The agent loop unrolled into ordinary dataframe columns

python
from polar_llama import (
    mcp_tools, tools_to_response_model, execute_tool_calls,
    tool_results_to_message, combine_messages, inference_messages, Provider,
)

tools = mcp_tools("http://localhost:8811/mcp")     # tools/list introspection
ToolCalls = tools_to_response_model(tools)          # emission schema

df = (
    df
    # 1. Emit: the LLM parameterizes N calls per row (structured output)
    .with_columns(calls=pl.col("meal").llama.inference_async(
        provider=Provider.OPENAI, model="gpt-4o-mini", response_model=ToolCalls))
    # 2. Execute: all calls across all rows, in parallel, errors as data
    .with_columns(results=execute_tool_calls(
        pl.col("calls"), transport="http://localhost:8811/mcp", tools=tools))
    # 3. Synthesize: fold results back through a second inference pass
    .with_columns(answer=inference_messages(
        combine_messages(
            pl.col("meal").llama.to_message(role="user"),
            tool_results_to_message(pl.col("results")),
        ),
        provider=Provider.OPENAI, model="gpt-4o-mini"))
)

Prompt Optimization (DSPy-style)

Declare a task, then let an optimizer tune instructions or mine few-shot demos

python
import polars as pl
from polar_llama import Predict, Signature, BootstrapFewShot, InstructionOptimizer, evaluate

# 1. Declare the task
module = Predict(
    Signature("question -> answer", instructions="Answer concisely."),
    provider="openai",
    model="gpt-4o-mini",
)

# 2. Labeled training data
trainset = pl.DataFrame({
    "question": ["What is 2+2?", "Capital of France?", "Largest planet?"],
    "answer": ["4", "Paris", "Jupiter"],
})

# 3. A metric: (gold row, prediction) -> bool | float
def exact_match(example, prediction):
    return example["answer"].strip().lower() == (prediction["answer"] or "").strip().lower()

# 4a. Bootstrap few-shot demos from rows the model already gets right
compiled = BootstrapFewShot(metric=exact_match, max_demos=4).compile(module, trainset)

# 4b. Or search for better instructions (COPRO-style)
optimizer = InstructionOptimizer(metric=exact_match, n_candidates=4)
compiled = optimizer.compile(module, trainset)
print(optimizer.history)  # [(instructions, score), ...]

# 5. Run the optimized module on new data; outputs land in pred_* columns
result = compiled(pl.DataFrame({"question": ["What is 3+3?"]}))
print(result["pred_answer"])

# Score any module against a labeled set
print(evaluate(compiled, trainset, exact_match).score)

Production Runs

Features from earlier releases for long, expensive batch jobs

python
import polars as pl
from polar_llama import (
    inference_async, Provider, inference_stream, ResponseCache, DedupeStats,
)

# Streaming (0.6.0+): token deltas via a callback, Struct{text, finished} per row
df = df.with_columns(
    streamed=inference_stream(pl.col("prompt"), provider=Provider.OPENAI,
                              model="gpt-4o-mini", on_token=lambda i, d: print(d, end=""))
)

# Checkpointing (0.6.1+): re-run after a crash and only unfinished rows hit the API
df = df.with_columns(
    answer=inference_async(pl.col("prompt"), provider=Provider.OPENAI,
                           model="gpt-4o-mini", checkpoint="run1.ckpt")
)

# Usage & cost (0.6.2+): Struct{response, usage{input_tokens, ..., cost_usd}}
df = df.with_columns(
    r=inference_async(pl.col("prompt"), provider=Provider.OPENAI,
                      model="gpt-4o-mini", usage=True)
)
spend = df.select(pl.col("r").struct.field("usage").struct.field("cost_usd").sum())

# Dedupe + persistent response cache (0.6.3+): pay once per unique request
stats = DedupeStats()
df = df.with_columns(
    cached=inference_async(pl.col("prompt"), model="gpt-4o-mini",
                           response_cache=ResponseCache("responses.cache", ttl="24h"),
                           dedupe_stats=stats)
)
print(stats.hit_rate, stats.calls_made)

Research Workflows

Qualitative-coding and survey tooling from the 0.7.x releases

python
import polars as pl
from polar_llama import (
    Provider, induce_codebook, apply_codebook, cohens_kappa, krippendorffs_alpha, QualityConfig, quality_report, export_review_sample, import_corrections,
)

# Codebook induction (0.7.0+): discover themes, then apply them as multi-label codes
result = induce_codebook(responses, "text", provider=Provider.OPENAI, model="gpt-4o-mini")
coded = result.df.with_columns(
    labels=apply_codebook(pl.col("text"), result.codebook, provider=Provider.OPENAI)
)

# Agreement (0.7.1+): LLM vs. human and across a rater panel, per group
labels.group_by("batch").agg(
    kappa=cohens_kappa("llm_label", "human_label"),
    alpha=krippendorffs_alpha(["rater_1", "rater_2", "rater_3"]),
)

# Survey quality flags (0.7.2+): graded scores, never drops a row
report = quality_report(survey_df, QualityConfig(
    id_column="respondent_id", grid_columns=["g1", "g2", "g3"],
    text_columns=["oe1"], duration_column="duration_s",
))
report.summary

# Human review loop (0.7.3+): sample for review, then score the corrections
export_review_sample(coded_df, n=100, strata="code", path="review_batch.csv")
review = import_corrections(coded_df, reviewed_df, code_column="code")
print(review.kappa, review.n_changed)

On-Device Inference (Apple Silicon, in-process engine)

Batched generation via mlx-lm, no API keys, no network

python
import polars as pl
import polar_llama  # registers the .llama namespace

df = pl.DataFrame({"ticket": [
    "My laptop won't turn on even when it's plugged in.",
    "I forgot my password and I'm locked out of my account.",
]})

tagged = df.with_columns(
    tag=pl.col("ticket").llama.inference_local(
        model="mlx-community/gemma-3n-E4B-it-lm-4bit",
        system="Classify the ticket as exactly one of: Hardware, Account, Billing.",
        engine="in_process",   # on-device mlx-lm, batched over the column
        max_tokens=16,
        temperature=0.0,
    )
)

Data Analysis Pipeline

Process customer feedback at scale

python
import polars as pl
from polar_llama import string_to_message, inference_async, Provider

# Load customer feedback data
feedback_df = pl.DataFrame({
    'customer_id': [101, 102, 103, 104, 105],
    'feedback': [
        'The product is amazing but shipping was slow',
        'Great quality, highly recommend!',
        'Disappointed with customer service',
        'Perfect for my needs, will buy again',
        'Product arrived damaged, requesting refund'
    ]
})

# Create sentiment analysis prompts
sentiment_prompt = """Analyze the sentiment of this customer feedback
and classify it as Positive, Negative, or Neutral.
Also provide a brief reason.

Feedback: {feedback}"""

df = feedback_df.with_columns(
    prompt=pl.format(sentiment_prompt, pl.col('feedback'))
)

# Convert to messages and run inference
df = df.with_columns(
    message=string_to_message("prompt", message_type='user')
)

df = df.with_columns(
    sentiment_analysis=inference_async('message',
                                      provider=Provider.OPENAI,
                                      model='gpt-4o-mini')
)

# Extract key insights
print(df.select(['customer_id', 'feedback', 'sentiment_analysis']))

Vector Similarity Search

Generate embeddings, then find nearest neighbors with HNSW

python
from polar_llama import knn_hnsw, embedding_async, Provider

# Create corpus of documents
corpus = pl.DataFrame({
    "doc": ["AI research", "cooking tips", "machine learning", "recipes"]
}).with_columns(
    embedding=embedding_async(pl.col("doc"), provider=Provider.OPENAI)
)

# Create query
query = pl.DataFrame({
    "query": ["artificial intelligence"]
}).with_columns(
    query_emb=embedding_async(pl.col("query"), provider=Provider.OPENAI),
    corpus_emb=pl.lit([corpus["embedding"].to_list()])
).with_columns(
    neighbors=knn_hnsw(
        pl.col("query_emb"),
        pl.col("corpus_emb").list.first(),
        k=2  # Find 2 nearest neighbors
    )
)

# Get nearest neighbor documents
indices = query["neighbors"][0]
print(corpus[indices]["doc"])  # ['AI research', 'machine learning']

Taxonomy-Based Tagging

Classify documents with reasoning, reflection, and confidence scores

python
import polars as pl
from polar_llama import tag_taxonomy, Provider

# Define your taxonomy
taxonomy = {
    "sentiment": {
        "description": "The emotional tone of the text",
        "values": {
            "positive": "Text expresses positive emotions or favorable opinions",
            "negative": "Text expresses negative emotions or unfavorable opinions",
            "neutral": "Text is factual and objective without clear emotional content"
        }
    },
    "urgency": {
        "description": "How urgent the content is",
        "values": {
            "high": "Requires immediate attention",
            "medium": "Should be addressed soon",
            "low": "Can be addressed at any time"
        }
    }
}

df = pl.DataFrame({
    "id": [1, 2],
    "message": [
        "URGENT: Server is down!",
        "Thanks for your help yesterday."
    ]
})

result = df.with_columns(
    tags=tag_taxonomy(
        pl.col("message"),
        taxonomy,
        provider=Provider.GROQ,
        model="llama-3.3-70b-versatile"
    )
)

# Extract specific values
result.select([
    "message",
    pl.col("tags").struct.field("sentiment").struct.field("value").alias("sentiment"),
    pl.col("tags").struct.field("sentiment").struct.field("confidence").alias("confidence"),
    pl.col("tags").struct.field("urgency").struct.field("value").alias("urgency")
])

# Per-candidate reasoning: thinking is a list of {value, reasoning} (0.5.3+)
result.select(
    "id",
    pl.col("tags").struct.field("sentiment").struct.field("thinking").alias("thinking"),
).explode("thinking").unnest("thinking")

Provider Support

Six inference targets: five hosted providers plus on-device MLX

OpenAI

Default model: gpt-4o-mini

python
df = df.with_columns(
    answer=inference_async('prompt',
                          provider=Provider.OPENAI,
                          model='gpt-4o-mini')
)

Anthropic (Claude)

Default model: claude-opus-4-8; supports cache=True for prompt caching

python
df = df.with_columns(
    answer=inference_async('prompt',
                          provider=Provider.ANTHROPIC,
                          model='claude-opus-4-8',
                          system_prompt='You are a helpful assistant.',
                          cache=True)
)

AWS Bedrock

Default model: us.anthropic.claude-haiku-4-5-20251001-v1:0; region resolved from AWS_REGION / AWS_DEFAULT_REGION

python
# Requires AWS credentials configured
df = df.with_columns(
    answer=inference_async('prompt',
                          provider='bedrock',
                          model='us.anthropic.claude-haiku-4-5-20251001-v1:0')
)

Google Gemini

Default model: gemini-2.5-flash; native system_instruction and JSON-schema structured outputs

python
df = df.with_columns(
    answer=inference_async('prompt',
                          provider=Provider.GEMINI,
                          model='gemini-2.5-flash')
)

Groq

Default model: llama-3.3-70b-versatile; GROQ_BASE_URL overrides the endpoint (0.6.0+)

python
df = df.with_columns(
    answer=inference_async('prompt',
                          provider=Provider.GROQ,
                          model='llama-3.3-70b-versatile')
)

Local (Apple Silicon / MLX)

No API key, no network: the server engine points at a local OpenAI-compatible endpoint, and in_process drives mlx-lm directly

python
# engine="server" (default): point at a local server you started yourself
df = df.with_columns(
    answer=pl.col('prompt').llama.inference_local(
        model='mlx-community/gemma-4-e2b-it-4bit',
        engine='server',
        base_url='http://localhost:8080',
    )
)

# engine="in_process": batched generation directly via mlx-lm
df = df.with_columns(
    answer=pl.col('prompt').llama.inference_local(
        model='mlx-community/gemma-4-e2b-it-4bit',
        engine='in_process',
        max_tokens=256,
    )
)

API Surface

Core expressions exported from polar_llama

FunctionPurpose
inference_async(expr, *, provider, model, response_model, cache, system_prompt, checkpoint, usage, price_table, dedupe, response_cache, dedupe_stats)Parallel async inference; plus prompt caching, checkpointing, usage/cost, dedupe and a response cache
inference(expr, *, provider, model, response_model)Synchronous inference (deprecated in favor of inference_async)
inference_messages(expr, *, provider, model, response_model, cache, checkpoint, usage, price_table, dedupe, response_cache, dedupe_stats)Multi-turn conversation inference over JSON or List(Struct) message arrays
inference_stream(expr, *, provider, model, on_token, messages)Token-by-token streaming; returns Struct{text, finished} per row
string_to_message(expr, *, message_type)Convert text to a {role, content} message
combine_messages(*exprs)Merge message columns/arrays into one ordered conversation
tag_taxonomy(expr, taxonomy, *, provider, model)Classify text against a taxonomy with reasoning, reflection, and confidence
embedding_async(expr, *, provider, model)Parallel embedding generation (OpenAI, Gemini, Bedrock)
cosine_similarity / dot_product / euclidean_distance(vec1, vec2)Rust-powered vector similarity metrics
knn_hnsw(query_expr, reference_expr, *, k)Stateless approximate nearest-neighbor search via HNSW
HnswIndex.build(df, id_col, embedding_col, ...) / .add / .remove / .query / .query_one / .knn / .compact / .save / HnswIndex.loadPersistent, incrementally updatable HNSW index
mcp_tools(transport, *, timeout_s)Fetch tool definitions from an MCP server (tools/list)
tools_to_response_model(tools, *, model_name)Build a Pydantic emission schema so the LLM emits structured tool calls
execute_tool_calls(expr, *, transport, executor, tools, concurrency, timeout_s)Run every emitted call of every row in parallel; failures are data
tool_results_to_message(expr, *, role)Render tool results as a message for the synthesis inference pass
Signature / Predict / evaluate / BootstrapFewShot / InstructionOptimizerDSPy-style prompt optimization engine (polar_llama.optimize)
Checkpoint(path, *, flush_every, retry_failed, on_mismatch)Checkpoint store configuration for checkpoint=
register_model_price(provider, model, *, input_per_1m, output_per_1m, cached_input_per_1m) / set_price_table(table)Add or override prices used for cost_usd
ResponseCache(path, ttl, on_mismatch) / DedupeStats()Persistent cross-job response cache and dedupe counters
cluster_embeddings(expr, *, k, k_min, k_max, max_iter, n_init, seed, silhouette_sample)Whole-column spherical k-means with automatic k selection
induce_codebook(df, column, *, provider, model, embedding_column, k, n_exemplars, ...)Embed, cluster, and LLM-name a codebook; returns .df and .codebook
apply_codebook(expr, codebook, *, provider, model) / codebook_to_taxonomy(codebook)Multi-label coding against a codebook / bridge to tag_taxonomy
cohens_kappa(a, b, *, weights, n_bootstrap, ci, seed) / krippendorffs_alpha(cols, *, level, n_bootstrap, ci, seed)Inter-rater reliability as aggregation expressions
quality_report(df, config, *, output_column) / QualityConfig(...)Per-respondent survey quality flags plus a summary table
straightlining_score / gibberish_score / duplicate_answer_score / response_length_score / speeder_score / ai_likelihoodThe individual quality scores as standalone expressions
export_review_sample / import_corrections / corrections_to_trainset / retune_from_correctionsHuman-in-the-loop review loop feeding BootstrapFewShot
col(...).llama.inference_local(*, model, system, engine, base_url, max_tokens, temperature, top_p, stop, usage, price_table)On-device inference on Apple Silicon via mlx-lm
polar_llama.local.make_local_inference_fn(model, *, engine, collapse, max_tokens, ...)Build an inference_fn that backs the optimizer with on-device Gemma 3n

Every expression is also available on the fluent .llama namespace (pl.col("text").llama.inference_async(...), .llama.to_message(...), .llama.embedding(...), .llama.inference_stream(...), .llama.cohens_kappa(...), and so on). DataFrame-level orchestration functions (induce_codebook, quality_report, the review-loop functions) are plain functions, not namespace methods.

Advanced Features

Environment Configuration

Set up your API keys and overrides in a .env file:

.envbash
OPENAI_API_KEY=your_openai_key
ANTHROPIC_API_KEY=your_anthropic_key
GEMINI_API_KEY=your_gemini_key
GROQ_API_KEY=your_groq_key
AWS_ACCESS_KEY_ID=your_aws_key
AWS_SECRET_ACCESS_KEY=your_aws_secret
AWS_REGION=us-east-1

# Optional endpoint overrides for proxies and gateways (0.3.0+)
OPENAI_BASE_URL=https://your-proxy.example.com
ANTHROPIC_BASE_URL=https://your-proxy.example.com
GROQ_BASE_URL=https://your-proxy.example.com         # 0.6.0+

# Bound concurrent in-flight requests per batch (default: 64)
POLAR_LLAMA_MAX_CONCURRENCY=64

# Local MLX backend (Apple Silicon only)
POLAR_LLAMA_LOCAL_COLLAPSE=1        # collapsed prefix prefill for inference_local (0.5.1+)
POLAR_LLAMA_LOCAL_KV_BITS=4         # quantized batched KV cache, 0.5.0+ (mutually exclusive with COLLAPSE)

Prompt Caching

Share a cached system prefix across rows (Anthropic cache_control):

python
from polar_llama import CacheConfig, CacheStrategy

# Simple: enable automatic caching
df = df.with_columns(
    response=inference_async(
        pl.col("prompt"),
        provider=Provider.ANTHROPIC,
        model="claude-opus-4-8",
        system_prompt="You are a careful, concise research assistant.",
        cache=True,   # AUTO strategy, min_tokens=1024, ttl="5m"
    )
)

# Advanced: configure caching behavior explicitly
config = CacheConfig(strategy=CacheStrategy.SYSTEM_PROMPT, ttl="1h")
df = df.with_columns(
    response=inference_async(pl.col("prompt"), cache=config)
)

Testing

Run tests with configured providers:

bash
pip install -r tests/requirements.txt
pytest tests/ -v
cargo test --test model_client_tests -- --nocapture

# Local MLX backend: CPU-safe logic tests only (no GPU, no mlx import)
pytest tests/ -m "not local_gpu"

Changelog Highlights (0.5.2 → 0.8.0)

  • 0.8.0: HnswIndex: build / add / remove / query / knn / compact / save / load over a staging buffer + tombstones on instant-distance
  • 0.7.3: export_review_sample, import_corrections (with kappa), corrections_to_trainset, retune_from_corrections; optional [excel] extra
  • 0.7.2: quality_report / QualityConfig: straightlining, gibberish, duplicate-answer, length-outlier and speeder scores, plus an opt-in near-duplicate / likely-AI tier
  • 0.7.1: cohens_kappa and krippendorffs_alpha as aggregation expressions, bit-for-bit with sklearn / krippendorff, with bootstrap CIs
  • 0.7.0: cluster_embeddings (hand-rolled spherical k-means in Rust), induce_codebook, apply_codebook, codebook_to_taxonomy
  • 0.6.3: dedupe=True collapses duplicate rows in-run; response_cache= / ResponseCache(path, ttl=...) reuses results across jobs; DedupeStats reports hits and calls
  • 0.6.2: usage=True returns Struct{response, usage{input_tokens, output_tokens, cached_tokens, latency_ms, cost_usd}} from an overridable price table (price_table=, register_model_price)
  • 0.6.1: checkpoint="path" / Checkpoint(...) on inference_async and inference_messages: resumable runs over a crash-durable Parquet store keyed by content + config hash
  • 0.6.0: inference_stream() with an on_token(row_index, delta) callback and a Struct{text, finished} column; native SSE for OpenAI, Groq, Anthropic; GROQ_BASE_URL override
  • 0.5.3: tag_taxonomy() works on OpenAI strict mode again: thinking is now List[{value, reasoning}] and $ref siblings are stripped (#51); new warning for Dict-typed response models
  • 0.5.2: fixed in-process local inference on Gemma 3n (mlx-lm #1384 patch applied at load time; a masked ZeroDivisionError in BatchGenerator teardown no longer hides the real error)
  • 0.3.0 – 0.5.1: tool use / MCP, provider-native prompt caching, DSPy-style prompt optimizer, local MLX backend, and the on-device prompt-tuning bridge

Common Use Cases

📊Data Analysis

Process large datasets with AI insights: sentiment analysis, classification, entity extraction with validated structured outputs

🛡️Long-Running Batch Jobs

Resume after crashes, track spend per row, and never pay twice for the same request

🔬Qualitative and Survey Research

Induce codebooks, measure LLM/human agreement, flag low-quality respondents, and fold reviewer corrections back into the prompt

🧭Semantic Search and Retrieval

Build a persistent HNSW index once, update it incrementally, and query it from lazy pipelines, with offline embeddings from 0.8.1

🧰Tool-Augmented Pipelines

Let the LLM call databases, internal APIs, or MCP servers at scale, with every call, result, and retry as an ordinary dataframe column

🔒Private, Local Inference

Run classification, extraction, or tuning on local models with no API keys and no data leaving the machine

Resources
GitHub RepositoryPyPI PackagePolars Documentation

Licensed under MIT.

Questions or issues? Open one on GitHub.