diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 0000000..a792d5f
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,15 @@
+# Changelog
+
+## [0.1.0] - 2026-06-08
+
+Initial release of biofuse.
+
+- Read-only FUSE views of VCF Zarr data in standard bioinformatics formats,
+  generated on demand using vcztools.
+- `mount-plink` — PLINK 1.9 binary view (`.bed`/`.bim`/`.fam`), diploid input.
+- `mount-bgen` — BGEN view (`.bgen`/`.sample`/`.bgen.bgi`) using zlib
+  level 0 fixed-size blocks for O(1) random access; haploid supported,
+  mixed ploidy not supported by the mount.
+- Inherits vcztools view filter / backend / log options on both commands, plus
+  `--basename` and `--access-log`.
+- Requires vcztools >= 0.2.
diff --git a/README.md b/README.md
index e5e3749..4f5e5db 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,6 @@
+[![CI](https://github.com/sgkit-dev/biofuse/actions/workflows/ci.yml/badge.svg?branch=main)](https://github.com/sgkit-dev/biofuse/actions/workflows/ci.yml)
+[![PyPI Downloads](https://static.pepy.tech/badge/biofuse)](https://pepy.tech/projects/biofuse)
+
 # biofuse
 
 Read-only views of VCF Zarr (VCZ) data in standard bioinformatics file formats
@@ -6,37 +9,92 @@ via a FUSE filesystem. Currently supported views:
 - **PLINK 1.9 binary** (`.bed` / `.bim` / `.fam`) — via `mount-plink`.
 - **Oxford BGEN** (`.bgen` / `.sample` / `.bgen.bgi`) — via `mount-bgen`.
 
-## Status
-
-Pre-release. The mount serves the streaming file (`.bed` / `.bgen`) on
-demand via a worker subprocess running the matching
-[`vcztools`](https://github.com/sgkit-dev/vcztools) encoder
-(`BedEncoder` / `BgenEncoder`); the static sidecars are computed once
-at mount time and held in the worker's memory.
-
-The mounted PLINK view supports the access patterns of `plink1.9` and
-`plink2` for typical analysis commands (`--freq`, `--missing`,
-`--hardy`, etc.) — see `tests/test_plink_apps.py` for the verified set.
-The mounted BGEN view always uses zlib level 0 (stored, fixed-size
-blocks) for O(1) random access; `bgenix` / `qctool` parity checks live
-in `tests/test_bgen_apps.py`.
+The streaming file (`.bed` / `.bgen`) is generated on demand using the
+matching [`vcztools`](https://github.com/sgkit-dev/vcztools) encoder; the
+static sidecars are computed once at mount time.
+
+## Stability and correctness
+
+A core design principle of biofuse is that **the mount must never become
+unresponsive**. All the work of decoding VCF Zarr and encoding it into PLINK
+or BGEN bytes is delegated to
+[vcztools](https://github.com/sgkit-dev/vcztools); biofuse itself does one
+thing — present that data as a correct, dependable read-only filesystem.
+Keeping the two responsibilities separate keeps the surface biofuse has to get
+exactly right small.
+
+- **The filesystem stays responsive under load.** Encoding runs off the
+  filesystem's request-handling path, and every read and open is bounded by a
+  timeout: a slow or stuck encode returns a normal I/O error (`EIO` /
+  `EAGAIN`) rather than blocking. One wedged file handle cannot freeze the
+  others, and unmount never hangs.
+- **Failures are contained.** An error inside the encoder surfaces to the
+  caller as an I/O error, not a crash — the mount keeps serving every other
+  file.
+- **The view is read-only and immutable.** Writes, truncation and appends are
+  rejected with `EROFS`; the sidecars are computed once when the mount starts
+  and served unchanged for its lifetime.
+- **POSIX behaviour is tested.** A dedicated filesystem test
+  harness (`fs_tests/`) exercises syscall semantics (`read` / `pread` /
+  `lseek`, `stat`, `mmap`, directory listing, write rejection), cross-checks
+  the served bytes against a reference, and runs read-stress and liveness
+  probes that confirm the mount stays responsive while the streaming file is
+  saturated.
+
+## Performance and access patterns
+
+biofuse is optimised for **linear, sequential reads** — the access pattern
+used by the majority of downstream tools, which stream variants start-to-end.
+The streaming `.bed` / `.bgen` file is encoded on demand as the consumer reads
+forward, and bytes already produced are buffered, so reading straight through
+the file does no redundant work. The mounts are verified against `plink1.9`
+and `plink2` (`--bfile`, `--freq`, `--missing`, `--hardy`, …) for PLINK, and
+`bgenix`, `qctool`, REGENIE, SAIGE, BOLT-LMM and `plink2 --bgen` for BGEN.
+
+Random and backward access still work, but are slower: seeking backwards or
+skipping far ahead can make biofuse re-encode from an earlier point in the
+file. The kernel page cache holds bytes that have already been served, so
+re-reading a region — and multi-pass tools that scan the file more than once
+(e.g. flashpca) — stays cheap once the data is warm.
+
+For BGEN, the `.bgen` payload uses zlib level 0 (stored, fixed-size variant
+blocks) together with the `.bgen.bgi` index, so a tool can fetch an individual
+variant by byte range without decompressing or re-encoding the rest of the
+file — variant-targeted access (e.g. `bgenix -v`) is efficient as well as
+whole-file scans.
+
+The sidecar files (`.bim` / `.fam` / `.sample` / `.bgen.bgi`) are computed
+once when the mount starts, so reads of them are always fast regardless of
+access order. These can be suppressed individually where not needed
+(e.g., the .bgen.bgi can be large and is not needed for many workloads).
+
+Because the streaming file is produced on demand, a read that stalls beyond an
+internal timeout surfaces as `EIO` rather than blocking indefinitely; in
+practice this only appears under pathological random-access load.
 
 ## Install
 
-biofuse depends on libfuse 3 system headers when building from source:
+biofuse depends on libfuse 3 system headers (`pyfuse3` builds from source):
 
 ```bash
 sudo apt-get install -y fuse3 libfuse3-dev pkg-config
 ```
 
-Then with [`uv`](https://docs.astral.sh/uv/):
+Then:
 
 ```bash
-uv sync --group test
+python -m pip install biofuse      # or: uv pip install biofuse
 ```
 
-vcztools is currently consumed as a sibling-directory path dependency
-(`../vcztools`); see `pyproject.toml`.
+### Remote and zipped stores
+
+The `vcz_url` argument and the inherited `--backend-storage` /
+`--storage-option` options accept cloud, fsspec, and HTTP stores, plus
+`.vcz.zip` files. biofuse depends on bare `vcztools`; to mount cloud-backed
+stores install the matching vcztools extra, e.g.
+`pip install 'vcztools[obstore]'` or `pip install 'vcztools[icechunk]'`. See
+the [vcztools documentation](https://sgkit-dev.github.io/vcztools/) for the
+available storage backends.
 
 ## Usage
 
@@ -66,6 +124,11 @@ Example:
 ```bash
 mkdir /tmp/plink-mnt
 biofuse mount-plink ./sample.vcz /tmp/plink-mnt &
+# The mount runs in the foreground, so it is backgrounded with `&`. It is
+# not ready the instant the process starts — it first opens the VCZ and
+# builds the sidecars — so wait for the mounted file to appear before
+# running the consumer tool.
+until [ -e /tmp/plink-mnt/sample.bed ]; do sleep 0.1; done
 plink1.9 --bfile /tmp/plink-mnt/sample --freq --out ./out
 fusermount3 -u /tmp/plink-mnt
 ```
@@ -81,8 +144,7 @@ Mounts a read-only directory at `/mount/dir` containing
 uses zlib level 0 (stored, fixed-size variant blocks) so byte-range
 random access is O(1); downstream tools (bgenix, qctool, REGENIE,
 SAIGE, BOLT-LMM, plink2 `--bgen`) consume the mount unchanged. The
-`.bgen.bgi` SQLite sidecar is generated once at mount time and held in
-the worker's memory alongside `.sample`.
+`.bgen.bgi` SQLite sidecar and `.sample` are generated once at mount time.
 
 Options mirror `mount-plink`: `--basename`, `--access-log`, and the
 shared bcftools-style filter / backend / log set inherited from
@@ -94,6 +156,8 @@ Example:
 ```bash
 mkdir /tmp/bgen-mnt
 biofuse mount-bgen ./sample.vcz /tmp/bgen-mnt &
+# Wait for the mount to come up before reading from it (see mount-plink above).
+until [ -e /tmp/bgen-mnt/sample.bgen ]; do sleep 0.1; done
 bgenix -g /tmp/bgen-mnt/sample.bgen -list
 fusermount3 -u /tmp/bgen-mnt
 ```
@@ -129,6 +193,3 @@ uv run prek install                    # install git pre-commit hook (one-off)
 uv run --only-group=lint prek -c prek.toml run --all-files
 ```
 
-## Licence
-
-Apache 2.0. See `LICENSE`.
diff --git a/pyproject.toml b/pyproject.toml
index 4eb47c1..aabe4f9 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -18,7 +18,7 @@ dependencies = [
 ]
 requires-python = ">=3.11"
 classifiers = [
-  "Development Status :: 3 - Alpha",
+  "Development Status :: 4 - Beta",
   "Operating System :: POSIX :: Linux",
   "Operating System :: MacOS :: MacOS X",
   "Intended Audience :: Science/Research",