livekit-protocol: remove FunctionCall.extra, check every livekit-agents release

.changeset/remove-function-call-extra.md

@@ -0,0 +1,5 @@
+---
+"livekit-protocol": patch
+---
+
+Remove `FunctionCall.extra`: livekit-agents 1.7.0 to 1.8.8 fail to encode the session history with it.

.github/workflows/regression-agents-session-history.yml

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+name: Regression - livekit-agents releases encode their session history
+
+# Every published livekit-agents release must still encode its session history with a
+# livekit-protocol 1.x build: those releases accept livekit-protocol<2 and are already deployed.
+
+on:
+  pull_request:
+    branches:
+      - main
+    paths:
+      - livekit-protocol/**
+      - tests/protocol/**
+      - .github/workflows/regression-agents-session-history.yml
+  workflow_dispatch:
+
+jobs:
+  regression-agents-session-history:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          submodules: true
+
+      - uses: astral-sh/setup-uv@20cfd1bf945f4377ade1205e4dbc17946fc9a30d # v10.0.1
+        with:
+          python-version: "3.12"
+
+      - name: Build livekit-protocol
+        run: uv build --wheel livekit-protocol -o dist
+
+      - name: Encode a session history with every livekit-agents release
+        run: |
+          set -euo pipefail
+          wheel=$(ls dist/livekit_protocol-*.whl)
+          case "$(basename "$wheel")" in
+            livekit_protocol-1.*) ;;
+            *) echo "livekit-protocol 2+ cannot reach livekit-agents 1.x"; exit 0 ;;
+          esac
+          versions=$(curl -sf https://pypi.org/pypi/livekit-agents/json | uvx --with packaging python -c '
+          import json, sys
+          from packaging.version import Version
+          releases = json.load(sys.stdin)["releases"]
+          print(" ".join(v for v in sorted(releases, key=Version)
+                         if releases[v] and not Version(v).is_prerelease
+                         and Version("1.7.0") <= Version(v) < Version("2")))')
+          failed=""
+          for v in $versions; do
+            uv venv -q --allow-existing "venv-$v"
+            VIRTUAL_ENV="venv-$v" uv pip install -q "livekit-agents==$v"
+            VIRTUAL_ENV="venv-$v" uv pip install -q --no-deps --reinstall "$wheel"
+            "venv-$v/bin/python" tests/protocol/regression_agents_session_history.py || failed="$failed $v"
+          done
+          if [ -n "$failed" ]; then
+            echo "::error::livekit-agents releases that cannot encode a session history:$failed"
+            exit 1
+          fi

tests/protocol/regression_agents_session_history.py

@@ -0,0 +1,31 @@
+"""Regression: livekit-protocol 1.1.28 added FunctionCall.extra, and livekit-agents 1.7.0 to 1.8.8
+failed to upload the session history (TypeError: bad argument type for built-in operation).
+
+Encodes a session history the way an installed livekit-agents release uploads it.
+
+livekit-agents 1.7.0 to 1.8.8 fill every field the installed protocol declares on a chat item
+from the attribute of the same name, so a new field can break releases already deployed.
+Run with one livekit-agents release and the livekit-protocol build under test installed.
+"""
+
+from importlib.metadata import version
+
+from livekit.agents import llm
+
+items = [
+    llm.ChatMessage(role="user", content=["hi", "there"], extra={"lk.redacted": True}),
+    llm.FunctionCall(
+        call_id="call_1",
+        name="lookup",
+        arguments="{}",
+        extra={
+            "google": {"thought_signature": "c2ln"},
+            "__livekit_agents_tool_non_blocking": True,
+        },
+    ),
+    llm.FunctionCallOutput(call_id="call_1", name="lookup", output="ok", is_error=False),
+]
+llm.ChatContext(items).to_proto().SerializeToString()
+print(
+    f"livekit-agents {version('livekit-agents')} with livekit-protocol {version('livekit-protocol')}: ok"
+)