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 0.23.0

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 0.23.0
File Size Uploaded
llmshim-0.23.0.tar.gz 2.1 MB Details

Built distributions (wheels)

Table of built distributions (wheels) for llmshim 0.23.0
File
llmshim-0.23.0-py3-none-win_amd64.whl Python 3 none Windows x86-64 Details
llmshim-0.23.0-py3-none-manylinux_2_17_x86_64.manylinux2014_x86_64.whl Python 3 none Linux glibc 2.17+ x86-64 Details
llmshim-0.23.0-py3-none-manylinux_2_17_aarch64.manylinux2014_aarch64.whl Python 3 none Linux glibc 2.17+ ARM64 Details
llmshim-0.23.0-py3-none-macosx_11_0_arm64.whl Python 3 none macOS 11.0+ ARM64 Details
llmshim-0.23.0-py3-none-macosx_10_12_x86_64.whl Python 3 none macOS 10.12+ x86-64 Details

Total release size: 37.2 MB

Release files / llmshim-0.23.0.tar.gz

Download URL llmshim-0.23.0.tar.gz
Size 2.1 MB
Tags Source
SHA-256 checksum
How to use checksums
3709d71f130d2f1cc6ef1d38ba7eba7507728e2d9659889e6ffb6ac23b796a96
BLAKE2b-256 checksum
How to use checksums
285bf0bdeec9a2033725d61d710ea8690c275e9ec49bd406ac17ee0ac3a923bd
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 Oct 1, 2026.

Transparency log

Release files / llmshim-0.23.0-py3-none-win_amd64.whl

Download URL llmshim-0.23.0-py3-none-win_amd64.whl
Size 7.3 MB
Tags Python 3 Windows x86-64
SHA-256 checksum
How to use checksums
a4344a6685e4771e81fd563a7527263b01df50d98bcd0496f173eaa1170fc5f2
BLAKE2b-256 checksum
How to use checksums
e2420db2895c79a6abc787dd5438cf94360b6d03243760592f13fc1b40c396e5
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 Oct 1, 2026.

Transparency log

Release files / llmshim-0.23.0-py3-none-manylinux_2_17_x86_64.manylinux2014_x86_64.whl

Download URL llmshim-0.23.0-py3-none-manylinux_2_17_x86_64.manylinux2014_x86_64.whl
Size 7.3 MB
Tags Linux glibc 2.17+ x86-64 Python 3
SHA-256 checksum
How to use checksums
499a6660d2bbfd22d2554c4a3ba78836655381a74a5c6d587bec4ffaeea3228c
BLAKE2b-256 checksum
How to use checksums
61d4b9cdf72d48fb8fcf049da64f46cc6308cc1c9a157be2d3536dd523bd1088
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 Oct 1, 2026.

Transparency log

Release files / llmshim-0.23.0-py3-none-manylinux_2_17_aarch64.manylinux2014_aarch64.whl

Download URL llmshim-0.23.0-py3-none-manylinux_2_17_aarch64.manylinux2014_aarch64.whl
Size 6.8 MB
Tags Linux glibc 2.17+ ARM64 Python 3
SHA-256 checksum
How to use checksums
34b64175c7a6737852c11ad1a2ab30f5894dd27a5538310b570e68ce3ee8198a
BLAKE2b-256 checksum
How to use checksums
565928ddca83359d86b8bdef95b84b6707f01cf923a907ef3cc413ee2d870c9a
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 Oct 1, 2026.

Transparency log

Release files / llmshim-0.23.0-py3-none-macosx_11_0_arm64.whl

Download URL llmshim-0.23.0-py3-none-macosx_11_0_arm64.whl
Size 6.7 MB
Tags Python 3 macOS 11.0+ ARM64
SHA-256 checksum
How to use checksums
2914edf58781d0e01f1c27d4d0e37772982e7a6e501b338215e26cbd4868682c
BLAKE2b-256 checksum
How to use checksums
be064edf8c0773c7aff9cf3a65af8c06a4bfaaa752fca7bc3c0a46ec31267674
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 Oct 1, 2026.

Transparency log

Release files / llmshim-0.23.0-py3-none-macosx_10_12_x86_64.whl

Download URL llmshim-0.23.0-py3-none-macosx_10_12_x86_64.whl
Size 7.0 MB
Tags Python 3 macOS 10.12+ x86-64
SHA-256 checksum
How to use checksums
844ca185e73a90814435e435753af60ee89ad926df47c6bf5b1732ffa711a532
BLAKE2b-256 checksum
How to use checksums
932d9594f28f2d98003b51ffdcc0a5e7d720eb9aa32ba2e0dddeff880dd3f502
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 Oct 1, 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

This release

0.23.0 This release

6 release files

0.18.0

6 release files

0.17.0

6 release files

0.16.0

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