Skip to main content

llmshim

One interface, every LLM provider. The proxy server starts automatically — no setup needed.

Install

pip install llmshim

Configure

import llmshim

# Set API keys (writes to ~/.llmshim/config.toml — only needed once)
llmshim.configure(
    anthropic="sk-ant-...",
    openai="sk-...",
    gemini="AIza...",
    xai="xai-...",
    openrouter="sk-or-...",
)

Or from the CLI: llmshim configure

Self-hosted servers (vLLM / SGLang)

vLLM and SGLang are configured via environment variables (not config.toml) — the auto-spawned proxy inherits them from your Python process. Set them before your first call:

import os

os.environ["VLLM_BASE_URL"] = "http://localhost:8000/v1"
os.environ["VLLM_API_KEY"] = "..."       # optional
os.environ["SGLANG_BASE_URL"] = "http://localhost:30000/v1"
os.environ["SGLANG_API_KEY"] = "..."     # optional

Then address them via the model string — vllm/<served-model> or sglang/<served-model> (see the model table below).

Chat

import llmshim

resp = llmshim.chat("claude-sonnet-5-5", "What is Rust?")
print(resp["message"]["content"])

With options (all map to the API's provider-agnostic config):

resp = llmshim.chat(
    "openai/gpt-6-sol",
    "Explain quicksort",
    max_tokens=500,
    temperature=0.7,
    top_p=0.9,
    top_k=40,
    stop=["\n\n"],
    reasoning_effort="high",
)

With message history:

resp = llmshim.chat("claude-sonnet-5-5", [
    {"role": "system", "content": "You are a pirate."},
    {"role": "user", "content": "Hello!"},
], max_tokens=500)

Streaming

for event in llmshim.stream("claude-sonnet-5-5", "Write a poem"):
    if event["type"] == "content":
        print(event["text"], end="", flush=True)
    elif event["type"] == "reasoning":
        pass  # thinking tokens
    elif event["type"] == "usage":
        print(f"\n[↑{event['input_tokens']} ↓{event['output_tokens']}]")

Multi-Model Conversations

Switch models mid-conversation. History carries over.

messages = [{"role": "user", "content": "What is a closure?"}]

r1 = llmshim.chat("claude-sonnet-5-5", messages, max_tokens=500)
print(f"Claude: {r1['message']['content']}")

messages.append({"role": "assistant", "content": r1["message"]["content"]})
messages.append({"role": "user", "content": "Now explain differently."})

r2 = llmshim.chat("gpt-6-sol", messages, max_tokens=500)
print(f"GPT: {r2['message']['content']}")

Reasoning / Thinking

Two provider-agnostic knobs control reasoning; both are clamped to the nearest tier the target model supports:

  • reasoning_effort — "none", "low", "medium", "high", "xhigh", or "max"
  • reasoning_mode — "standard" (default) or "pro" (requests substantially more model work; native on OpenAI gpt-5.6/-pro, emulated as an effort bump elsewhere)
resp = llmshim.chat(
    "claude-sonnet-5-5",
    "Solve: x^2 - 5x + 6 = 0",
    max_tokens=4000,
    reasoning_effort="high",
    reasoning_mode="pro",
)
print(resp["reasoning"])        # thinking content
print(resp["message"]["content"])  # answer

For full native control, bypass the unified mapping with a namespaced provider_config (see below), e.g. provider_config={"x-anthropic": {"thinking": {"type": "adaptive"}, "output_config": {"effort": "high"}}}.

Provider-Specific Controls (provider_config)

provider_config merges into the request root and carries anything the unified config doesn't cover. Native provider controls MUST be namespaced per provider (x-anthropic, x-openai, x-gemini, x-openrouter, x-vllm, x-sglang); it also carries the top-level tools, response_format, and reasoning_summary keys.

resp = llmshim.chat(
    "anthropic/claude-sonnet-5-5",
    "Solve this step by step: 17 * 23",
    max_tokens=4000,
    provider_config={
        # native Anthropic adaptive-thinking control
        "x-anthropic": {"thinking": {"type": "adaptive"}, "output_config": {"effort": "high"}},
    },
)

OpenRouter routing preferences use the x-openrouter namespace:

resp = llmshim.chat(
    "openrouter/anthropic/claude-sonnet-5",
    "Hello",
    max_tokens=200,
    provider_config={"x-openrouter": {"provider": {"sort": "throughput"}}},
)

Tool Use / Function Calling

tools = [{
    "type": "function",
    "function": {
        "name": "get_weather",
        "description": "Get current weather",
        "parameters": {
            "type": "object",
            "properties": {"city": {"type": "string"}},
            "required": ["city"],
        },
    },
}]

resp = llmshim.chat("claude-sonnet-5-5", "Weather in Tokyo?", max_tokens=500, tools=tools)
for tc in resp["message"].get("tool_calls", []):
    print(f"{tc['function']['name']}({tc['function']['arguments']})")

Tools are accepted in OpenAI Chat Completions format and auto-translated to each provider's native format.

Fallback Chains

resp = llmshim.chat(
    "anthropic/claude-sonnet-5-5",
    "Hello",
    max_tokens=100,
    fallback=["openai/gpt-6-sol", "gemini/gemini-3.8-flash"],
)

Error Handling

Non-streaming errors (bad model, unknown provider, provider failures) raise LlmShimError, which carries the API's structured error fields:

try:
    llmshim.chat("unknown/model", "hi")
except llmshim.LlmShimError as e:
    print(e.status_code)  # 400
    print(e.code)         # "bad_request"
    print(e.message)      # human-readable message

Streaming errors that occur mid-stream instead arrive as an error event (event["type"] == "error"); an HTTP error before the stream starts still raises LlmShimError.

Types

Spec-faithful TypedDict definitions are available in llmshim.types (and the common ones are re-exported at the top level) for static type-checking:

from llmshim.types import ChatResponse, StreamEvent, Message, Config

resp: ChatResponse = llmshim.chat("claude-sonnet-5-5", "hi")

Available: ChatRequest, ChatResponse, Config, Message, ToolCall, Usage, ResponseMessage, ModelEntry, ModelsResponse, HealthResponse, ErrorResponse, and the StreamEvent union (ContentEvent, ReasoningEvent, ToolCallEvent, UsageEvent, DoneEvent, ErrorEvent).

Other

llmshim.models()   # list available models
llmshim.health()   # {"status": "ok", "providers": [...]}

How It Works

On first call, the package:

  1. Finds the llmshim binary (bundled, on PATH, or in repo)
  2. Lets the child bind a random localhost port and reads its private startup record
  3. Pins the child's one-time TLS certificate, authenticates every request, and keeps a parent-liveness pipe open
  4. Server stops automatically when Python exits

No Docker, no background services, no manual server management.

Development

The unit tests under tests/ are fully mocked — they run a local HTTP server returning canned JSON and SSE, so they need no API keys and make no real provider calls:

pip install httpx pytest
pytest tests/

test_e2e.py is a separate LIVE suite that spawns the real binary and makes billed provider calls; run it only when you deliberately want to hit real APIs.

Advertised Models

Provider Models
OpenAI gpt-6-astra, gpt-6-sol, gpt-6-luna
Anthropic claude-fable-5-1, claude-opus-5-5, claude-sonnet-5-5, claude-haiku-4-5-20251001
Gemini gemini-3.8-flash, gemini-3.5-flash-lite
xAI grok-4.6

Call llmshim.models() for the live list filtered to your configured providers.

OpenRouter & self-hosted (vLLM / SGLang)

These providers are addressed by the model string plus environment variables — any model the upstream serves is reachable, so they aren't in the table above.

Provider Address as Env vars Native controls
OpenRouter openrouter/<vendor>/<model> (e.g. openrouter/anthropic/claude-sonnet-5) OPENROUTER_API_KEY (or llmshim.configure(openrouter=...)) provider_config={"x-openrouter": {...}} (provider, models, transforms)
vLLM vllm/<served-model> VLLM_BASE_URL (+ optional VLLM_API_KEY) provider_config={"x-vllm": {...}}
SGLang sglang/<served-model> SGLANG_BASE_URL (+ optional SGLANG_API_KEY) provider_config={"x-sglang": {...}}

Metadata

Release files for llmshim 0.16.0

For a detailed explanation of source distributions (sdists) and built distributions (wheels), please see the package formats documentation.

Source distribution (sdist)

Source distribution for llmshim 0.16.0
File Size Uploaded
llmshim-0.16.0.tar.gz 2.0 MB Details

Built distributions (wheels)

Table of built distributions (wheels) for llmshim 0.16.0
File
llmshim-0.16.0-py3-none-win_amd64.whl Python 3 none Windows x86-64 Details
llmshim-0.16.0-py3-none-manylinux_2_17_x86_64.manylinux2014_x86_64.whl Python 3 none Linux glibc 2.17+ x86-64 Details
llmshim-0.16.0-py3-none-manylinux_2_17_aarch64.manylinux2014_aarch64.whl Python 3 none Linux glibc 2.17+ ARM64 Details
llmshim-0.16.0-py3-none-macosx_11_0_arm64.whl Python 3 none macOS 11.0+ ARM64 Details
llmshim-0.16.0-py3-none-macosx_10_12_x86_64.whl Python 3 none macOS 10.12+ x86-64 Details

Total release size: 36.0 MB

Release files / llmshim-0.16.0.tar.gz

Download URL llmshim-0.16.0.tar.gz
Size 2.0 MB
Tags Source
SHA-256 checksum
How to use checksums
1cbddb352fba89058faa45674a00930a071e07e333bbc7caf0c44fa5a38b98d9
BLAKE2b-256 checksum
How to use checksums
6ed06fcfe74a55bbffb60967ef0a9fe1848da7a29042764cb11bc24384cbcb58
Upload date
Uploaded using Trusted Publishing?
What is trusted publishing?
Yes
Uploaded via twine/7.0.0 CPython/3.13.14

Provenance

Provenance describes where a file came from. On PyPI, provenance is shared via attestations, which provide a verifiable record of the build or publishing details. View details, limitations and caveats.

PyPI Publish Attestation

PyPI verified that this artifact, at this checksum, originated from the publisher listed below.

Signed by GitHub Actions, verified by PyPI on Sep 29, 2026.

Transparency log

Release files / llmshim-0.16.0-py3-none-win_amd64.whl

Download URL llmshim-0.16.0-py3-none-win_amd64.whl
Size 7.1 MB
Tags Python 3 Windows x86-64
SHA-256 checksum
How to use checksums
ffad60696903bff4d7e76bcc72b8b15e45bec5af5bab221d86373bc2d27f1104
BLAKE2b-256 checksum
How to use checksums
f6d639c627877b860c1674c0b2027c6cf8475db3c687232df01656ecded6e881
Upload date
Uploaded using Trusted Publishing?
What is trusted publishing?
Yes
Uploaded via twine/7.0.0 CPython/3.13.14

Provenance

Provenance describes where a file came from. On PyPI, provenance is shared via attestations, which provide a verifiable record of the build or publishing details. View details, limitations and caveats.

PyPI Publish Attestation

PyPI verified that this artifact, at this checksum, originated from the publisher listed below.

Signed by GitHub Actions, verified by PyPI on Sep 29, 2026.

Transparency log

Release files / llmshim-0.16.0-py3-none-manylinux_2_17_x86_64.manylinux2014_x86_64.whl

Download URL llmshim-0.16.0-py3-none-manylinux_2_17_x86_64.manylinux2014_x86_64.whl
Size 7.0 MB
Tags Linux glibc 2.17+ x86-64 Python 3
SHA-256 checksum
How to use checksums
137c6c8095a6ad910774b86bba43d0bcb3c56c10d166d89d97941ac658c44764
BLAKE2b-256 checksum
How to use checksums
de5a61e6052836b6103a48d4d5506a3d793edec9b51bf6cf8b804511b0410f9f
Upload date
Uploaded using Trusted Publishing?
What is trusted publishing?
Yes
Uploaded via twine/7.0.0 CPython/3.13.14

Provenance

Provenance describes where a file came from. On PyPI, provenance is shared via attestations, which provide a verifiable record of the build or publishing details. View details, limitations and caveats.

PyPI Publish Attestation

PyPI verified that this artifact, at this checksum, originated from the publisher listed below.

Signed by GitHub Actions, verified by PyPI on Sep 29, 2026.

Transparency log

Release files / llmshim-0.16.0-py3-none-manylinux_2_17_aarch64.manylinux2014_aarch64.whl

Download URL llmshim-0.16.0-py3-none-manylinux_2_17_aarch64.manylinux2014_aarch64.whl
Size 6.6 MB
Tags Linux glibc 2.17+ ARM64 Python 3
SHA-256 checksum
How to use checksums
b6d97f38d185b58c619d090d7600922b2803c6e1db162f860231462c60ca5a9f
BLAKE2b-256 checksum
How to use checksums
0d9df1ff02026c8d18c795a15a12329d0b4a347dd26bdff1082f74de969a970f
Upload date
Uploaded using Trusted Publishing?
What is trusted publishing?
Yes
Uploaded via twine/7.0.0 CPython/3.13.14

Provenance

Provenance describes where a file came from. On PyPI, provenance is shared via attestations, which provide a verifiable record of the build or publishing details. View details, limitations and caveats.

PyPI Publish Attestation

PyPI verified that this artifact, at this checksum, originated from the publisher listed below.

Signed by GitHub Actions, verified by PyPI on Sep 29, 2026.

Transparency log

Release files / llmshim-0.16.0-py3-none-macosx_11_0_arm64.whl

Download URL llmshim-0.16.0-py3-none-macosx_11_0_arm64.whl
Size 6.5 MB
Tags Python 3 macOS 11.0+ ARM64
SHA-256 checksum
How to use checksums
332f6dbd3aeeb41b2260fcfd0fdd2ec293c188d2011a5fc2bca437d4df392210
BLAKE2b-256 checksum
How to use checksums
e9d14b81a789fb63fd44c21c7dd28bdf42d2f565b59d07f0352649539e4bcaf9
Upload date
Uploaded using Trusted Publishing?
What is trusted publishing?
Yes
Uploaded via twine/7.0.0 CPython/3.13.14

Provenance

Provenance describes where a file came from. On PyPI, provenance is shared via attestations, which provide a verifiable record of the build or publishing details. View details, limitations and caveats.

PyPI Publish Attestation

PyPI verified that this artifact, at this checksum, originated from the publisher listed below.

Signed by GitHub Actions, verified by PyPI on Sep 29, 2026.

Transparency log

Release files / llmshim-0.16.0-py3-none-macosx_10_12_x86_64.whl

Download URL llmshim-0.16.0-py3-none-macosx_10_12_x86_64.whl
Size 6.8 MB
Tags Python 3 macOS 10.12+ x86-64
SHA-256 checksum
How to use checksums
98d4011ae750e8bbbb71efe4157002a53e50f6ab084e751f284facedeb604357
BLAKE2b-256 checksum
How to use checksums
ceee49e1c1e3ecb85e0843e7af8caa989a9448e665c78cf694c91f7b84242ee9
Upload date
Uploaded using Trusted Publishing?
What is trusted publishing?
Yes
Uploaded via twine/7.0.0 CPython/3.13.14

Provenance

Provenance describes where a file came from. On PyPI, provenance is shared via attestations, which provide a verifiable record of the build or publishing details. View details, limitations and caveats.

PyPI Publish Attestation

PyPI verified that this artifact, at this checksum, originated from the publisher listed below.

Signed by GitHub Actions, verified by PyPI on Sep 29, 2026.

Transparency log

Release history Release notifications | RSS feed

0.28.0

6 release files

0.27.2

6 release files

0.27.1

6 release files

0.18.0

6 release files

0.17.0

6 release files

This release

0.16.0 This release

6 release files

0.15.0

6 release files

0.14.0

6 release files

0.13.0

6 release files

0.12.1

6 release files

0.11.0

6 release files

0.10.1

6 release files

0.10.0

6 release files

0.9.0

6 release files

0.8.1

6 release files

0.8.0

6 release files

0.7.2

6 release files

0.7.1

6 release files

0.7.0

6 release files

0.6.0

6 release files

0.5.0

6 release files

0.4.0

6 release files

0.3.7

6 release files

0.3.6

6 release files

0.3.5

6 release files

0.3.4

6 release files

0.3.3

6 release files

0.3.2

6 release files

0.3.1

6 release files

0.3.0

6 release files

0.2.3

6 release files

0.2.2

6 release files

0.2.1

6 release files

0.2.0

6 release files

0.1.26

6 release files

0.1.25

6 release files

0.1.21

6 release files

0.1.20

6 release files

0.1.16

6 release files

0.1.15

6 release files

0.1.14

6 release files

0.1.13

6 release files

0.1.12

6 release files

0.1.11

6 release files

0.1.10

6 release files

0.1.9

6 release files

0.1.8

6 release files

0.1.7

6 release files

0.1.6

6 release files

0.1.4

6 release files

0.1.3

6 release files

0.1.2

6 release files

0.1.0

2 release files

Anthropic, PBC Visionary sponsor Bloomberg Visionary sponsor Hudson River Trading Visionary sponsor Meta Visionary sponsor NVIDIA Visionary sponsor Microsoft Sustainability sponsor Depot Continuous Integration AWS Cloud computing and Security Sponsor Datadog Monitoring Fastly CDN Google Download Analytics Sentry Error logging StatusPage Status page