feat: integrate the Chat modality with the shared Rust core

.github/workflows/ci.yml

@@ -25,9 +25,9 @@ jobs:
         with:
           persist-credentials: false
 
-      - uses: dtolnay/rust-toolchain@5b842231ba77f5c045dba54ac5560fed2db780e2 # nightly
+      - uses: dtolnay/rust-toolchain@5b842231ba77f5c045dba54ac5560fed2db780e2 # nightly-2026-01-10
         with:
-          toolchain: nightly
+          toolchain: nightly-2026-01-10
           components: rustfmt, clippy
 
       - uses: dtolnay/rust-toolchain@5b842231ba77f5c045dba54ac5560fed2db780e2 # stable
@@ -43,11 +43,11 @@ jobs:
       - name: cargo check wasm32
         run: cargo check --target wasm32-unknown-unknown -p truapi-server
 
-      - name: cargo +nightly fmt --check
-        run: cargo +nightly fmt --check
+      - name: cargo +nightly-2026-01-10 fmt --check
+        run: cargo +nightly-2026-01-10 fmt --check
 
-      - name: cargo +nightly clippy
-        run: cargo +nightly clippy --workspace --all-targets --all-features -- -D warnings
+      - name: cargo +nightly-2026-01-10 clippy
+        run: cargo +nightly-2026-01-10 clippy --workspace --all-targets --all-features -- -D warnings
 
       - name: cargo test
         run: cargo test --workspace --all-features
@@ -77,9 +77,9 @@ jobs:
         with:
           toolchain: stable
 
-      - uses: dtolnay/rust-toolchain@5b842231ba77f5c045dba54ac5560fed2db780e2 # nightly
+      - uses: dtolnay/rust-toolchain@5b842231ba77f5c045dba54ac5560fed2db780e2 # nightly-2026-01-10
         with:
-          toolchain: nightly
+          toolchain: nightly-2026-01-10
           components: rustfmt
 
       - uses: Swatinem/rust-cache@e18b497796c12c097a38f9edb9d0641fb99eee32 # v2

.github/workflows/deploy-docs.yml

@@ -37,9 +37,9 @@ jobs:
       - name: Configure Pages
         uses: actions/configure-pages@45bfe0192ca1faeb007ade9deae92b16b8254a0d # v6.0.0
 
-      - uses: dtolnay/rust-toolchain@5b842231ba77f5c045dba54ac5560fed2db780e2 # nightly
+      - uses: dtolnay/rust-toolchain@5b842231ba77f5c045dba54ac5560fed2db780e2 # nightly-2026-01-10
         with:
-          toolchain: nightly
+          toolchain: nightly-2026-01-10
           components: rustfmt
 
       - name: Install workspace dependencies

.github/workflows/deploy-playground.yml

@@ -39,9 +39,9 @@ jobs:
         with:
           toolchain: stable
 
-      - uses: dtolnay/rust-toolchain@5b842231ba77f5c045dba54ac5560fed2db780e2 # nightly
+      - uses: dtolnay/rust-toolchain@5b842231ba77f5c045dba54ac5560fed2db780e2 # nightly-2026-01-10
         with:
-          toolchain: nightly
+          toolchain: nightly-2026-01-10
           components: rustfmt
 
       - uses: Swatinem/rust-cache@e18b497796c12c097a38f9edb9d0641fb99eee32 # v2

.github/workflows/diagnosis-report.yml

@@ -38,21 +38,27 @@ jobs:
         run: |
           set -euo pipefail
 
-          # Host mode from the report title (`## Truapi <mode> Diagnosis`).
+          # Host mode and modality from the report title
+          # (`## Truapi <mode> [Chat] Diagnosis`).
           mode=$(printf '%s' "$BODY" \
-            | grep -ioP '##\s+Truapi\s+\K(Web|Desktop|Android|iOS)(?=\s+Diagnosis)' \
+            | grep -ioP '##\s+Truapi\s+\K(Web|Desktop|Android|iOS)(?=\s+(?:Chat\s+)?Diagnosis)' \
             | head -1 || true)
           if [ -z "$mode" ]; then
             gh issue comment "$ISSUE" --body \
-              "Could not read a host from this report (expected a \`## Truapi <Web|Desktop|Android|iOS> Diagnosis\` heading). Not filing a PR."
+              "Could not read a host from this report (expected a \`## Truapi <Web|Desktop|Android|iOS> [Chat] Diagnosis\` heading). Not filing a PR."
             exit 1
           fi
+          modality=spa
+          if printf '%s' "$BODY" | grep -iqP '##\s+Truapi\s+(Web|Desktop|Android|iOS)\s+Chat\s+Diagnosis'; then
+            modality=chat
+          fi
           host=$(printf '%s' "$mode" | tr '[:upper:]' '[:lower:]')
-          branch="diagnosis-report/$host"
-          file="explorer/diagnosis-reports/$host.md"
+          branch="diagnosis-report/$modality-$host"
+          file="explorer/diagnosis-reports/$modality/$host.md"
 
           git fetch origin main
           git switch -C "$branch" origin/main
+          mkdir -p "$(dirname "$file")"
           printf '%s\n' "$BODY" > "$file"
 
           git config user.name "github-actions[bot]"
@@ -64,7 +70,7 @@ jobs:
             exit 0
           fi
           git add "$file"
-          git commit -m "diagnosis: update $host report (from #$ISSUE)"
+          git commit -m "diagnosis: update $modality/$host report (from #$ISSUE)"
           git push -f "https://x-access-token:${GH_TOKEN}@github.com/${REPO}.git" "$branch"
 
           # One open PR per host branch: reuse it while it is open, open a new
@@ -73,7 +79,7 @@ jobs:
           url=$(gh pr list --head "$branch" --state open --json url --jq '.[0].url // empty')
           if [ -z "$url" ]; then
             url=$(gh pr create --base main --head "$branch" \
-              --title "diagnosis: $mode host report" \
+              --title "diagnosis: $mode $modality report" \
               --body "Updates \`$file\` from the diagnosis in #$ISSUE. The compatibility matrix is regenerated from the reports at build time.")
           fi
 

.github/workflows/release.yml

@@ -126,9 +126,9 @@ jobs:
           fi
 
       - if: steps.version.outputs.proceed == 'true'
-        uses: dtolnay/rust-toolchain@5b842231ba77f5c045dba54ac5560fed2db780e2 # nightly
+        uses: dtolnay/rust-toolchain@5b842231ba77f5c045dba54ac5560fed2db780e2 # nightly-2026-01-10
         with:
-          toolchain: nightly
+          toolchain: nightly-2026-01-10
           components: rustfmt
 
       - if: steps.version.outputs.proceed == 'true'

.gitignore

@@ -10,6 +10,7 @@ lerna-debug.log*
 # Build artifacts
 node_modules
 target
+/artifacts/
 
 # Gradle (Android workspace at repo root)
 /.gradle/

CLAUDE.md

@@ -115,7 +115,7 @@ After regenerating, rebuild the client and refresh the playground's link copy:
 
 ```bash
 cargo build --workspace
-cargo +nightly fmt --check
+cargo +nightly-2026-01-10 fmt --check
 cargo clippy --workspace --all-targets --all-features -- -D warnings
 cargo test --workspace
 ```

Makefile

@@ -3,9 +3,10 @@
 # Run `make help` for the list of targets.
 
 .DEFAULT_GOAL := help
-.PHONY: help setup build codegen test check clean playground wasm wasm-crypto-test uniffi uniffi-kotlin android-jni android-publish-local check-android-parity dotli-link dev dev-bootstrap dev-link-check e2e-dotli headless install matrix explorer
+.PHONY: help setup build codegen test check clean playground wasm wasm-crypto-test uniffi uniffi-kotlin ios-build ios-run ios-chat-run ios-chat-host-playground-run ios-chat-all android-jni android-publish-local check-android-parity dotli-link dev dev-bootstrap dev-link-check e2e-dotli headless install matrix explorer
 
 CARGO ?= cargo
+NIGHTLY_TOOLCHAIN ?= nightly-2026-01-10
 TRUAPI_PKG := js/packages/truapi
 PLAYGROUND := playground
 JS_PACKAGES := js/packages
@@ -41,6 +42,7 @@ setup: ## First-time setup: submodules, JS dependencies, generated artifacts.
 	# that only exist after codegen.sh, which also builds the packages.
 	npm ci --ignore-scripts
 	./scripts/codegen.sh
+	$(MAKE) uniffi
 	cd $(PLAYGROUND) && yarn install --frozen-lockfile
 	cd $(DOTLI) && bun install --frozen-lockfile
 	$(MAKE) dotli-link
@@ -63,7 +65,7 @@ install: headless ## Install the truapi-host CLI into Cargo's bin dir; use as `m
 	cargo install --path rust/crates/truapi-host-cli --bin truapi-host --locked --force
 
 codegen: ## Regenerate generated TS/Rust artifacts from the Rust crates.
-	./scripts/codegen.sh
+	TRUAPI_NIGHTLY_TOOLCHAIN="$(NIGHTLY_TOOLCHAIN)" ./scripts/codegen.sh
 	cd $(PLAYGROUND) && rm -rf node_modules/@parity && yarn install
 
 wasm: ## Rebuild the truapi-server WASM artifacts under js/packages/truapi-host/dist/wasm/.
@@ -103,6 +105,77 @@ uniffi: ## Regenerate Swift bindings from truapi-server cdylib.
 	cp $(UNIFFI_SWIFT_TMP)/truapi_serverFFI.modulemap \
 		ios/truapi-host/Sources/truapi_serverFFI/include/module.modulemap
 
+IOS_HOST := hosts/ios
+IOS_DERIVED_DATA ?= $(IOS_HOST)/build/DerivedData
+IOS_SIMULATOR_TARGET ?= aarch64-apple-ios-sim
+IOS_CONFIGURATION ?= Debug
+IOS_SWIFT_FLAGS ?= -DNIGHTLY -DW3S -DIOS_PASEO_E2E
+IOS_BUNDLE ?= io.pcf.polkadotapp.develop
+IOS_GOOGLE_SERVICE_PLIST ?= $(IOS_HOST)/polkadot-app/GoogleService/GoogleService-Info-Release.plist
+IOS_PRODUCT_HOST ?= truapi-playground.dot
+IOS_PRODUCT_URL ?= http://localhost:3100
+IOS_CHAT_PRODUCT_DIR ?= playground
+IOS_CHAT_PRODUCT_HOST ?= truapi-playground.dot
+IOS_CHAT_PRODUCT_NAME ?= TrUAPI Playground
+IOS_CHAT_PRODUCT_URL ?= http://127.0.0.1:3100
+IOS_HOST_PLAYGROUND_DIR ?= ../host-playground
+IOS_HOST_PLAYGROUND_HOST ?= host-playground.dot
+IOS_HOST_PLAYGROUND_NAME ?= Host Playground
+IOS_HOST_PLAYGROUND_URL ?= http://127.0.0.1:3101
+IOS_APP := $(abspath $(IOS_DERIVED_DATA)/Build/Products/$(IOS_CONFIGURATION)-iphonesimulator/polkadot-app.app)
+
+ios-build: uniffi ## Build matching Rust/Swift bindings and the TestFlight-configured iOS simulator app.
+	git submodule update --init --recursive $(IOS_HOST)
+	rustup target add $(IOS_SIMULATOR_TARGET)
+	$(CARGO) build -p truapi-server --release --features ws-bridge \
+		--target $(IOS_SIMULATOR_TARGET)
+	cd $(IOS_HOST) && RUN_IN_CI=true xcodebuild \
+		-project polkadot-app.xcodeproj \
+		-scheme polkadot-app \
+		-configuration $(IOS_CONFIGURATION) \
+		-destination 'generic/platform=iOS Simulator' \
+		-derivedDataPath $(abspath $(IOS_DERIVED_DATA)) \
+		ARCHS=arm64 \
+		ONLY_ACTIVE_ARCH=YES \
+		TRUAPI_SWIFT_FLAGS='$(IOS_SWIFT_FLAGS)' \
+		build
+	cp "$(IOS_GOOGLE_SERVICE_PLIST)" "$(IOS_APP)/GoogleService-Info.plist"
+	codesign --force --sign - "$(IOS_APP)"
+
+ios-run: ios-build ## Build and launch the local TrUAPI playground in an iPhone simulator.
+	TRUAPI_IOS_E2E_APP="$(IOS_APP)" \
+	TRUAPI_IOS_E2E_BUNDLE="$(IOS_BUNDLE)" \
+	TRUAPI_IOS_E2E_PRODUCT_HOST="$(IOS_PRODUCT_HOST)" \
+	TRUAPI_IOS_E2E_PRODUCT_URL="$(IOS_PRODUCT_URL)" \
+	node scripts/launch-ios-playground.mjs
+
+ios-chat-run: ios-build ## Run the TrUAPI Playground Chat diagnosis in an iPhone simulator.
+	TRUAPI_IOS_E2E_APP="$(IOS_APP)" \
+	TRUAPI_IOS_E2E_BUNDLE="$(IOS_BUNDLE)" \
+	TRUAPI_IOS_E2E_CHAT_PRODUCT_DIR="$(IOS_CHAT_PRODUCT_DIR)" \
+	TRUAPI_IOS_E2E_CHAT_PRODUCT_HOST="$(IOS_CHAT_PRODUCT_HOST)" \
+	TRUAPI_IOS_E2E_CHAT_PRODUCT_NAME="$(IOS_CHAT_PRODUCT_NAME)" \
+	TRUAPI_IOS_E2E_CHAT_PRODUCT_URL="$(IOS_CHAT_PRODUCT_URL)" \
+	node scripts/launch-ios-chat-playground.mjs
+
+ios-chat-host-playground-run: ios-build ## Verify Host Playground Chat through the workspace-linked TrUAPI client.
+	TRUAPI_IOS_E2E_APP="$(IOS_APP)" \
+	TRUAPI_IOS_E2E_BUNDLE="$(IOS_BUNDLE)" \
+	TRUAPI_IOS_E2E_CHAT_PRODUCT_DIR="$(abspath $(IOS_HOST_PLAYGROUND_DIR))" \
+	TRUAPI_IOS_E2E_CHAT_PRODUCT_HOST="$(IOS_HOST_PLAYGROUND_HOST)" \
+	TRUAPI_IOS_E2E_CHAT_PRODUCT_NAME="$(IOS_HOST_PLAYGROUND_NAME)" \
+	TRUAPI_IOS_E2E_CHAT_PRODUCT_URL="$(IOS_HOST_PLAYGROUND_URL)" \
+	TRUAPI_IOS_E2E_CHAT_ROOM_ID="host-playground-room" \
+	TRUAPI_IOS_E2E_CHAT_MESSAGE="!echo hello" \
+	TRUAPI_IOS_E2E_CHAT_DIAGNOSIS="0" \
+	TRUAPI_IOS_E2E_CHAT_EXPECTED_STARTUP_MESSAGE="" \
+	TRUAPI_IOS_E2E_CHAT_EXPECT_CUSTOM_RENDERER="0" \
+	TRUAPI_IOS_E2E_CHAT_SCREENSHOT="artifacts/host-playground-chat.png" \
+	TRUAPI_IOS_E2E_CHAT_TRUAPI_DIR="$(abspath js/packages/truapi)" \
+	node scripts/launch-ios-chat-playground.mjs
+
+ios-chat-all: ios-chat-run ios-chat-host-playground-run ## Run both local iOS Chat playground integrations.
+
 UNIFFI_KOTLIN_OUT := android/truapi-host/src/main/kotlin/generated
 
 uniffi-kotlin: ## Regenerate Kotlin UniFFI bindings from the truapi-server cdylib.
@@ -136,7 +209,7 @@ test: ## Run Rust + TypeScript client tests.
 check: ## Full verification suite (build, fmt, clippy, test, TS tests, playground build + lint).
 	cargo build --workspace
 	cargo check --target wasm32-unknown-unknown -p truapi-server
-	cargo +nightly fmt --check
+	cargo +$(NIGHTLY_TOOLCHAIN) fmt --check
 	cargo clippy --workspace --all-targets --all-features -- -D warnings
 	cargo test --workspace --all-features --all-targets
 	cd $(TRUAPI_PKG) && npm run build && npm test

README.md

@@ -120,8 +120,8 @@ controls, and examples.
 
 `scripts/battery.sh` drives that CLI from source over every code-generated
 example and writes both committed compatibility reports:
-`explorer/diagnosis-reports/signing-host-cli.md` from a direct signing-host run,
-and `pairing-host-cli.md` from a pairing host that the script pairs with a
+`explorer/diagnosis-reports/spa/signing-host-cli.md` from a direct signing-host
+run, and `spa/pairing-host-cli.md` from a pairing host that the script pairs with a
 signing host it starts itself.
 
 ```bash
@@ -139,6 +139,63 @@ yarn dev
 
 Open `https://dot.li/localhost:3000` inside the Polkadot Desktop Host. See [`playground/README.md`](playground/README.md) for deployment.
 
+To build the iOS host and open the playground in Simulator:
+
+```bash
+make ios-run
+```
+
+The target regenerates the UniFFI Swift bindings, builds the matching Rust
+simulator library, and builds the `hosts/ios` app with the Nightly feature
+flags and release Firebase app used by the Nightly TestFlight build. Native
+Chat and the Paseo chain catalog come from the same Nightly Remote Config as
+TestFlight. The executable keeps the development bundle and app-group identity
+so Simulator can reuse its already registered wallet; keychain data cannot be
+transferred to the production bundle. The simulator also adds the
+`IOS_PASEO_E2E` conveniences needed to start on the real `browse.dot` Browse tab
+and activate the embedded signing host. Embedded product host sessions use the
+same Paseo People and Bulletin chains selected by the Nightly app
+configuration. The launcher starts the playground at `http://localhost:3100`
+when needed and uses that local source only after Browse opens
+`truapi-playground.dot`. It refuses to launch if the local URL belongs to a
+different app. Override the product, URL, or simulator with `IOS_PRODUCT_HOST`,
+`IOS_PRODUCT_URL`, or `TRUAPI_IOS_E2E_DEVICE`. The simulator launch reuses the
+wallet and registered username already stored by the iOS app. Opening a product
+activates the embedded `truapi-host` signing-host session from that wallet; it
+does not provision or pair a signer-bot user.
+
+To exercise the shared-core Chat path with the first-party TrUAPI Playground
+worker, build and serve the local product, install its worker into the
+simulator app's product storage, and open its native Chat application:
+
+```bash
+make ios-chat-run
+```
+
+The launcher verifies the Chat connection and runs a correlated Chat-only
+diagnosis. The worker proves create-room idempotency, observes the new room on
+the live list subscription, posts text and custom messages, receives
+`!diagnose` through `chat_action_subscribe`, and serves live renderer trees.
+The launcher also verifies that a renderer update reaches native code and that
+the final Markdown report reaches CoreData. It writes the host-labelled report
+to `playground/test-results/ios-chat/diagnosis-report.md`. The product builds
+against the workspace-linked `@parity/truapi`. Override the product source,
+identity, SPA URL, room, input, or report path with
+`IOS_CHAT_PRODUCT_DIR`, `IOS_CHAT_PRODUCT_HOST`, `IOS_CHAT_PRODUCT_URL`,
+`TRUAPI_IOS_E2E_CHAT_ROOM_ID`, `TRUAPI_IOS_E2E_CHAT_MESSAGE`, or
+`TRUAPI_IOS_E2E_CHAT_REPORT`.
+
+The same harness can run the legacy Product SDK worker from the sibling
+`host-playground` checkout. This target builds the current TrUAPI client, links
+it over Host Playground's transitive `@parity/truapi`, then builds and runs
+that product:
+
+```bash
+make ios-chat-host-playground-run
+```
+
+Run both integrations with one iOS build using `make ios-chat-all`.
+
 ## Regenerate the TypeScript client
 
 When the Rust trait surface changes: