chore: bump to 0.9.0a1

Author: PsiACE

docs/releasing.md

@@ -9,7 +9,7 @@ Every package release tracks an upstream ACP schema tag from [`agentclientprotoc
    ACP_SCHEMA_VERSION=v0.4.5 make gen-all
    ```
    This refreshes `schema/` and the generated `src/acp/schema.py`.
-2. **Bump the SDK version** in `pyproject.toml` (and regenerate `uv.lock` if deps moved).
+2. **Bump the SDK version** in `pyproject.toml` using a PEP 440 version string (for example `0.9.0a1` for an alpha release), and sync `uv.lock` if the lockfile is tracked.
 3. **Run the standard gates:**
    ```bash
    make check   # Ruff format/lint, type analysis, dep hygiene
@@ -20,7 +20,7 @@ Every package release tracks an upstream ACP schema tag from [`agentclientprotoc
 ## Commit & review
 
 - Keep the diff tight: regenerated schema files, version bumps, doc updates, and any required fixture refresh (goldens, RPC tests, etc.).
-- Use a Conventional Commit such as `release: v0.4.5`.
+- Use a Conventional Commit such as `release: 0.9.0a1`.
 - In the PR description, capture:
   - The ACP schema tag you targeted.
   - Output from `make check` / `make test` (and optional Gemini tests if you ran them).
@@ -31,6 +31,7 @@ Every package release tracks an upstream ACP schema tag from [`agentclientprotoc
 Releases are automated by `on-release-main.yml` once the PR lands on `main`.
 
 1. Draft a GitHub Release for the new tag (the UI creates the tag if missing).
+   Use the exact package version as the tag, for example `0.9.0a1` or `0.9.0`.
 2. Publishing the release triggers the workflow, which:
    - Syncs the tag back into `pyproject.toml`.
    - Builds and uploads to PyPI via `uv publish` using `PYPI_TOKEN`.

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "agent-client-protocol"
-version = "0.8.1"
+version = "0.9.0a1"
 description = "A Python implement of Agent Client Protocol (ACP, by Zed Industries)"
 authors = [
     { name = "Chojan Shang", email = "psiace@apache.org" },