This release is a pre-release and may not be stable for production use.
baml_bridge
Python bindings for the BAML runtime (powered by bex_engine).
baml_bridge is the bridge layer that generated baml_sdk packages
import at runtime: it provides the BamlRuntime singleton, the
protobuf encoder/decoder and the function/method factories.
from baml_bridge import BamlRuntime
rt = BamlRuntime.initialize_runtime(
root_path=".",
files={"main.baml": baml_source},
)
This package is generally consumed indirectly via the code generated
by baml-cli generate --target python — direct use is reserved for
runtime authors and bridge tests.
Python callback execution
Passing a Python callable to BAML uses the environment of the call that invokes it. Reusing a callback across threads, event loops, or requests does not retain its registration environment.
| BAML entry | Python callback | Execution environment |
|---|---|---|
| Synchronous | Synchronous | Calling Python thread, with its current context |
| Synchronous | Coroutine result | Bridge-owned worker loop, with copied caller context |
| Asynchronous | Synchronous or coroutine result | Originating application loop, with copied entry context |
Each dispatch of an async entry receives a separate copy of its application
ContextVars. Callback writes do not change the awaiting task's context or
another dispatch's context. An async callback need not run in the caller's
exact asyncio.Task.
A synchronous entry blocks its calling thread, including any application loop running there. Coroutine callbacks of that entry must use resources of their executing worker loop. Awaiting resources owned by the blocked loop is unsupported.
Returned BAML closures support closure(...) and
await closure.call_async(...). Passing a closure back into BAML preserves
its native function handle. Each new invocation selects its own environment.
Cancelling a BAML call cancels executing coroutine callbacks on their owning loops. Callback tasks retain their arguments and context until their bodies and async cleanup finish. Cancellation does not interrupt a synchronous Python body. A callback that suppresses cancellation may finish later; its result does not revive the cancelled BAML call.
Requirements
- Python 3.10+
protobuf >= 6.31.1
License
Apache-2.0
4 maintainers
Metadata
4 maintainers
Release files for baml-bridge 0.20.2.dev2026100601
For a detailed explanation of source distributions (sdists) and built distributions (wheels), please see the package formats documentation.
Built distributions (wheels)
| File | Interpreter | ABI | Platform | Reset |
|---|---|---|---|---|
| baml_bridge-0.20.2.dev2026100601-cp310-abi3-macosx_11_0_arm64.whl | CPython 3.10 | abi3 | macOS 11.0+ ARM64 | Details |
| baml_bridge-0.20.2.dev2026100601-cp310-abi3-macosx_10_12_x86_64.whl | CPython 3.10 | abi3 | macOS 10.12+ x86-64 | Details |
Total release size: 29.6 MB
Release files / baml_bridge-0.20.2.dev2026100601-cp310-abi3-macosx_11_0_arm64.whl
| Download URL | baml_bridge-0.20.2.dev2026100601-cp310-abi3-macosx_11_0_arm64.whl |
|---|---|
| Size | 14.4 MB |
| Tags | CPython 3.10 abi3 macOS 11.0+ ARM64 |
|
SHA-256 checksum How to use checksums |
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|
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| Download URL | baml_bridge-0.20.2.dev2026100601-cp310-abi3-macosx_10_12_x86_64.whl |
|---|---|
| Size | 15.3 MB |
| Tags | CPython 3.10 abi3 macOS 10.12+ x86-64 |
|
SHA-256 checksum How to use checksums |
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|
Uploaded using Trusted Publishing? What is trusted publishing? |
Yes |
| Uploaded via |
twine/7.0.0 CPython/3.13.14
|
Provenance
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