diff --git a/AGENTS.md b/AGENTS.md
index 25533fd..e00f14a 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -4,7 +4,7 @@
 - The five gates CI runs: `python tests/parity/verify_acceptance.py`, `verify_effects.py`, `verify_streaming.py`, `verify_biquad.py` and `verify_mixdown_knee.py`. Lint is `python -m flake8` (defect checks only).
 - The deeper parity gates need built interpreters and the pinned CircuitPython oracle. Pass `--micropython` and `--circuitpython` explicitly; `verify_dsp.py` refuses a run with fewer than two interpreters. A stock `circuitpython` build is not the oracle (it has 14 voices; the oracle has 64). See [Running the parity gates](docs/how-it-works/parity-gates.md).
 - Never edit CircuitPython's own sources for the oracle, and never let a new module shadow one of CircuitPython's. Fixes for bugs that also exist upstream go in this repo's targets only, recorded in [upstream-diff](docs/how-it-works/upstream-diff.md); ask before adding a deviation.
-- Don't re-capture a golden, or move `CIRCUITPYTHON_ORACLE` or `DEPENDENCIES.lock`, without independent evidence and the reason written down ([CONTRIBUTING.md](CONTRIBUTING.md#rules-that-keep-the-port-honest)).
+- Don't re-capture a golden, or move a pin in `DEPENDENCIES.lock` (the CircuitPython oracle included), without independent evidence and the reason written down ([CONTRIBUTING.md](CONTRIBUTING.md#rules-that-keep-the-port-honest)).
 - The `audiomp3` decoder is fetched, not vendored: `scripts/fetch_deps.sh` puts it under `.deps/`. Tremor (`audiovorbis`) is vendored in `third_party/tremor`.
 - Import names match CircuitPython (`import audiocore`, `import synthio`), whichever runtime is underneath. The instrument and effect libraries live in [audiocomponents](https://github.com/PyDevices/audiocomponents), not here.
 - A frozen module wins over `/lib` on MicroPython and CircuitPython, so a copied or mip-installed `audiodsp` never runs until you rebuild or put `/lib` first. On a source checkout set `PYTHONPATH` (CPython) or `MICROPYPATH` (MicroPython).
diff --git a/CIRCUITPYTHON_ORACLE b/CIRCUITPYTHON_ORACLE
deleted file mode 100644
index b940bef..0000000
--- a/CIRCUITPYTHON_ORACLE
+++ /dev/null
@@ -1,10 +0,0 @@
-# The CircuitPython oracle pin. Every parity golden is measured against
-# this exact commit (tag 11.0.0-alpha.2; the pin moved from 11.0.0-alpha.1 on
-# 2026-10-22, from 10.3.0 on 2026-10-08 with audiodsp#201, from 10.2.1 to
-# 10.3.0 on 2026-09-09).
-# Moving it is a re-port, not a bump: every move is a resync with upstream
-# (docs/how-it-works/upstream-sync.md; the one before this was audiodsp#220). See also
-# docs/how-it-works/parity-gates.md (how the 64-voice oracle binary is built)
-# and docs/how-it-works/upstream-diff.md; tests/test_voice_ceiling_consistency.py
-# pins the binary's sha256.
-11.0.0-alpha.2 d53b2277cfad71589028e5da77c984c045db990d
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index ac16bf3..84e0b36 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -55,8 +55,8 @@ what each module is held to.
 
 ## Rules that keep the port honest
 
-- **Don't modify the CircuitPython oracle.** The tag in `CIRCUITPYTHON_ORACLE`
-  is what every parity golden is measured against. Edit CircuitPython's own
+- **Don't modify the CircuitPython oracle.** The `circuitpython` line in
+  `DEPENDENCIES.lock` is what every parity golden is measured against. Edit CircuitPython's own
   sources for it and parity quietly means something else. Moving the pin is a
   resync with upstream, done deliberately: see
   [Keeping in step with upstream](docs/how-it-works/upstream-sync.md).
@@ -65,7 +65,7 @@ what each module is held to.
   never shadow or rewrite one of CircuitPython's.
 - **Don't re-capture a parity golden casually.** A fix that is right can still
   change one; say what independent evidence shows it is right.
-- **Don't move the dependency pins** (`DEPENDENCIES.lock`, `CIRCUITPYTHON_ORACLE`)
+- **Don't move the dependency pins** (`DEPENDENCIES.lock`, which holds the CircuitPython oracle too)
   without saying why.
 - **A fix for a bug that also exists upstream** goes in this repository's
   targets only, recorded in
diff --git a/DEPENDENCIES.lock b/DEPENDENCIES.lock
index 5a1c09c..ef86212 100644
--- a/DEPENDENCIES.lock
+++ b/DEPENDENCIES.lock
@@ -4,3 +4,14 @@
 #      checkout vendors in its own lib/mp3; patches/adafruit_mp3/ applies
 #      on top.
 mp3 https://github.com/adafruit/Adafruit_MP3.git aac02afd9f24d2ee930f650156654ab9211a306a
+# circuitpython: the oracle pin. Every parity golden is measured against this
+#      exact commit (tag 11.0.0-alpha.2; the pin moved from 11.0.0-alpha.1 on
+#      2026-10-22, from 10.3.0 on 2026-10-08 with audiodsp#201, from 10.2.1 to
+#      10.3.0 on 2026-09-09). The build does not fetch it; scripts/fetch_deps.sh
+#      skips this line.
+# Moving it is a re-port, not a bump: every move is a resync with upstream
+# (docs/how-it-works/upstream-sync.md; the one before this was audiodsp#220). See also
+# docs/how-it-works/parity-gates.md (how the 64-voice oracle binary is built)
+# and docs/how-it-works/upstream-diff.md; tests/test_voice_ceiling_consistency.py
+# pins the binary's sha256.
+circuitpython https://github.com/adafruit/circuitpython.git d53b2277cfad71589028e5da77c984c045db990d
diff --git a/ROADMAP.md b/ROADMAP.md
index 04d0e16..216e246 100644
--- a/ROADMAP.md
+++ b/ROADMAP.md
@@ -25,7 +25,10 @@ audio pump holding up under live use such as a stompbox or a stage rig.
   `audiodynamics`, `audioecho`, `audiofilters`, `audiofreeverb`, `audiograph`,
   `audioladder`, `audiomixer`, `audioshaper`, `audiospeed`, `audioverb`).
 - The CircuitPython glue's folder takes a lasting name (`src/circuitpython_spike/`
-  becomes `src/circuitpython/`), and `CIRCUITPYTHON_ORACLE` joins `DEPENDENCIES.lock`.
+  becomes `src/circuitpython/`).
+- `audiocore`, `audiomp3`, `audiopump` and `synthio` report a `__revision__`
+  like the other modules, so a board can say which source each was built from
+  (today those four have none on MicroPython).
 
 Bugs, and things you need that don't work yet, go to
 [issues](https://github.com/PyDevices/audiodsp/issues).
diff --git a/docs/how-it-works/index.md b/docs/how-it-works/index.md
index 0a61736..81890c5 100644
--- a/docs/how-it-works/index.md
+++ b/docs/how-it-works/index.md
@@ -120,7 +120,7 @@ hardware layer. The modules you import did not change. The helper package is
 
 The committed synthesis, mixer, MIDI, streaming and effects fixtures match
 CircuitPython 11.0.0-alpha.2 PCM byte-for-byte, built at the same voice
-ceiling this port ships (the pin is in `CIRCUITPYTHON_ORACLE`). Import and API
+ceiling this port ships (the pin is the `circuitpython` line of `DEPENDENCIES.lock`). Import and API
 smoke success is not used as a substitute for those comparisons. The
 playback-facing pull protocol (`audiocore.get_buffer` and `reset_buffer`) is
 consumed by `pydevices`' `lib/audiodev` package (`AudioOut` in
diff --git a/docs/how-it-works/parity-gates.md b/docs/how-it-works/parity-gates.md
index e48607c..d04a1ea 100644
--- a/docs/how-it-works/parity-gates.md
+++ b/docs/how-it-works/parity-gates.md
@@ -9,7 +9,7 @@ to is in [the correctness standard](correctness-standard.md).
 
 ## The oracle binary
 
-CircuitPython at the tag in `CIRCUITPYTHON_ORACLE` is the oracle every
+CircuitPython at the commit on the `circuitpython` line of `DEPENDENCIES.lock` is the oracle every
 CircuitPython-shared parity golden is measured against. Build it as
 CircuitPython's unix coverage variant with `CIRCUITPY_SYNTHIO_MAX_CHANNELS=64`
 and this repository as its only audio user C module (`circuitpython.mk`), at
diff --git a/docs/how-it-works/upstream-diff.md b/docs/how-it-works/upstream-diff.md
index 1a0260e..d01324b 100644
--- a/docs/how-it-works/upstream-diff.md
+++ b/docs/how-it-works/upstream-diff.md
@@ -338,7 +338,7 @@ in audiocomponents' parity sequences on CPython and on MicroPython.
 
 The oracle moved from 10.3.0 to 11.0.0-alpha.1 (520805e12) on 2026-10-08,
 with the binary at `bin/circuitpython-oracle-11.0.0-alpha.1`
-(`CIRCUITPYTHON_ORACLE`, [`tests/test_voice_ceiling_consistency.py`](../../tests/test_voice_ceiling_consistency.py)). It moved
+(the `circuitpython` line of `DEPENDENCIES.lock`, [`tests/test_voice_ceiling_consistency.py`](../../tests/test_voice_ceiling_consistency.py)). It moved
 to take upstream's 6dddbda87, "audiodelays, audiofilters, audiofreeverb:
 buffer lengths and silence fills", which this port now has in full:
 
diff --git a/docs/how-it-works/upstream-sync.md b/docs/how-it-works/upstream-sync.md
index 2681f28..8fc57c1 100644
--- a/docs/how-it-works/upstream-sync.md
+++ b/docs/how-it-works/upstream-sync.md
@@ -14,7 +14,7 @@ The reasons behind each difference, with their measurements, are in
 
 ## When
 
-**Resync whenever the oracle pin moves.** The pin is `CIRCUITPYTHON_ORACLE`
+**Resync whenever the oracle pin moves.** The pin is the `circuitpython` line of `DEPENDENCIES.lock`
 at the repository root, and every CircuitPython-compatible gate is measured
 against the release it names. Moving the pin and resyncing are one change: the
 resync takes every fix and every addition upstream made between the old pin
diff --git a/scripts/fetch_deps.sh b/scripts/fetch_deps.sh
index ff87e73..9236e99 100755
--- a/scripts/fetch_deps.sh
+++ b/scripts/fetch_deps.sh
@@ -14,6 +14,8 @@ MODE="${1:-fetch}"
 rc=0
 while read -r name url rev; do
     [[ "$name" =~ ^#|^$ ]] && continue
+    # The CircuitPython oracle is a pin to test against, not a source to build.
+    [[ "$name" == circuitpython ]] && continue
     dir="$DEPS/$name"
     if [[ "$MODE" == "--check" ]]; then
         have=$(git -C "$dir" rev-parse HEAD 2>/dev/null || echo missing)
diff --git a/setup.py b/setup.py
index b5dccc6..93eb5ad 100644
--- a/setup.py
+++ b/setup.py
@@ -53,8 +53,9 @@ def fetch_mp3():
     no shell. An sdist already carries the sources and skips this.
     """
     lock = (HERE / "DEPENDENCIES.lock").read_text().split("\n")
-    name, url, rev = next(line.split() for line in lock
-                          if line.strip() and not line.startswith("#"))
+    name, url, rev = next(fields for fields in (line.split() for line in lock
+                                                if line.strip() and not line.startswith("#"))
+                          if fields[0] == "mp3")
     dest = HERE / ".deps" / name
 
     def git(*args):