When local.properties is missing, the build script now automatically:
- Checks ANDROID_HOME environment variable first
- Scans common Windows SDK locations:
- %LOCALAPPDATA%\Android\Sdk
- %USERPROFILE%\AppData\Local\Android\Sdk
- C:\Android\Sdk
- C:\Android
- Creates local.properties with the detected SDK path
- Displays helpful error message if SDK is not found
This allows the build script to work on machines without manual
configuration, making it easier to build APKs on different systems.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Add Windows batch script for building Android APKs:
- build-apk.bat debug - Build debug APK only
- build-apk.bat release - Build release APK only
- build-apk.bat - Build both debug and release APKs
- build-apk.bat clean - Clean build files
- build-apk.bat help - Show usage help
Output locations:
- Debug: app/build/outputs/apk/debug/app-debug.apk
- Release: app/build/outputs/apk/release/app-release.apk
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Major changes:
- Add complete Android app (service-party-android) with Jetpack Compose UI
- Implement real account-service API calls for keygen and sign sessions:
- POST /api/v1/co-managed/sessions (create keygen session)
- GET /api/v1/co-managed/sessions/by-invite-code/{code} (validate invite)
- POST /api/v1/co-managed/sessions/{id}/join (join keygen session)
- POST /api/v1/co-managed/sign (create sign session)
- GET /api/v1/co-managed/sign/by-invite-code/{code} (validate sign invite)
- POST /api/v1/co-managed/sign/{id}/join (join sign session)
- Add QR code generation and scanning for session invites
- Remove password requirement (use empty string)
- Add floating action button for wallet creation
- Add network type aware explorer links (mainnet/testnet)
Network configuration:
- Change default network to Kava mainnet for both Electron and Android apps
- Electron: main.ts, transaction.ts, Settings.tsx, Layout.tsx
- Android: Models.kt (NetworkType.MAINNET default)
Features:
- Full TSS keygen and sign protocol via gomobile bindings
- gRPC message routing for multi-party communication
- Cross-platform compatibility with service-party-app (Electron)
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Additional safeguards to prevent "CANCELLED: Cancelled on client" error:
1. Add `this.connected` check at the start of subscribeMessages()
2. Set messageStream to null after canceling old stream
3. Wrap new stream creation in try-catch to handle creation errors
4. Add logging for ignored cancel errors
These changes ensure that:
- subscribeMessages won't proceed if connection is lost
- Old stream is fully cleaned up before creating new one
- Errors during stream creation are properly caught and logged
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Root cause: After keygen/sign completion, the gRPC message stream was not
unsubscribed. On the second operation, prepareForSign/prepareForKeygen
would try to cancel the stale stream, causing "CANCELLED: Cancelled on client".
Changes in tss-handler.ts:
- Add grpcClient.unsubscribeMessages() in all cleanup paths:
- participateKeygen close handler
- participateKeygen error handler
- participateSign close handler
- participateSign error handler
- cancel() method
- Reset sessionId and partyId in all cleanup paths
Changes in main.ts:
- Add reconnection logic in app 'activate' event for macOS
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
The app was crashing with "CANCELLED: Cancelled on client" error when
opening the app a second time. This happened because:
1. When window was reopened, old gRPC streams were in cancelled state
2. prepareForSign/prepareForKeygen tried to subscribe on cancelled streams
3. The error was unhandled and crashed the app
Changes:
- Add isConnected() check in prepareForSign() and prepareForKeygen()
- Throw meaningful error when gRPC client is not connected
- Wrap all prepareFor* calls in try-catch in main.ts
- Return user-friendly error message instead of crashing
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
- Changed getGasPrice() to use eth_gasPrice RPC method instead of calculating
from baseFeePerGas (which is for EIP-1559 transactions)
- Added 10% buffer to gas price to ensure transaction gets included
- Updated Home.tsx to use gasPrice instead of maxFeePerGas for display
KAVA doesn't support EIP-1559, so we must use Legacy (Type 0) transactions
with gasPrice from eth_gasPrice RPC.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
KAVA EVM does not support EIP-1559 dynamic fee transactions.
Changed from EIP-1559 (Type 2) to Legacy (Type 0) format:
- prepareTransaction: Use [nonce, gasPrice, gasLimit, to, value, data, chainId, 0, 0]
- finalizeTransaction: Use EIP-155 v calculation (chainId * 2 + 35 + recoveryId)
- Remove type prefix (0x02) as Legacy transactions don't need it
- Update Home.tsx and CoSignSession.tsx to use gasPrice instead of maxFeePerGas
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
The signature was 64 bytes (r + s) but EVM transactions need 65 bytes (r + s + v).
Now the recovery ID is appended to the signature so the frontend can correctly
parse and broadcast the transaction.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
TSS-lib convention: threshold=t means (t+1) signers required.
User expectation: "2-of-3" means 2 signers needed.
Before this fix:
- Keygen used thresholdT directly (e.g., 2)
- TSS-lib interpreted as needing 3 signers (2+1)
- 2-of-3 wallet was actually 3-of-3!
After this fix:
- Both keygen and signing use (thresholdT-1)
- For 2-of-3: tss-lib threshold=1, needs 1+1=2 signers ✓
Files changed:
- tss-party/main.go: keygen and signing both use thresholdT-1
- tss-wasm/main.go: keygen and signing both use thresholdT-1
- pkg/tss/keygen.go: uses config.Threshold-1
- pkg/tss/signing.go: uses config.Threshold-1
BREAKING CHANGE: Existing wallets created before this fix used wrong
threshold and need to be regenerated. New wallets will work correctly.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
The signing code was using thresholdT-1 while keygen was using thresholdT,
causing Lagrange coefficient mismatch and "U doesn't equal T" error in round 9.
Root cause: commit d0c504dc added -1 to signing threshold to "match user expectation",
but this broke the keygen/sign consistency that TSS-lib requires.
Changes:
- tss-party/main.go: Sign now uses thresholdT (same as keygen)
- pkg/tss/signing.go: Add logging, emphasize threshold must match keygen
- tss-wasm/main.go: Add comment about threshold consistency
NOTE: This fix maintains backward compatibility with existing wallets.
No wallet regeneration is needed.
ROLLBACK: If this causes issues, revert to commit before this one.
Previous signing threshold was thresholdT-1 (commit d0c504dc).
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
When signing with fewer parties than keygen (e.g., 2-of-3 signing with only 2 parties),
the TSS-lib requires filtered save data containing only the participating parties.
Without this fix, signing fails with "U doesn't equal T" error because:
- Keygen creates save data for all N parties (e.g., 3 parties with indices 0, 1, 2)
- Sign uses only T parties (e.g., 2 parties with indices 1, 2)
- TSS-lib internal index validation fails due to mismatch
Changes:
- pkg/tss/signing.go: Use len(sortedPartyIDs) for partyCount and call BuildLocalSaveDataSubset
- tss-party/main.go: Add BuildLocalSaveDataSubset call for Electron app
- tss-wasm/main.go: Add BuildLocalSaveDataSubset call for WASM builds
This fix is backward compatible - when all parties participate, the subset equals the original data.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
User says "3-of-5" meaning 3 signers needed.
tss-lib threshold t means t+1 signers required.
Now we store t-1 at session creation (like persistent-only does).
Changes:
- co_managed_handler.go: tssThresholdT = req.ThresholdT - 1
- tss-party/main.go: remove -1 from sign (now consistent with keygen)
BREAKING: Existing co-managed wallets must be regenerated.
ROLLBACK: Revert this commit if signing still fails.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
The tss.NewParameters() expects the party count to match the number of
parties in peerCtx. For signing, this should be len(sortedPartyIDs)
(actual signing participants), not thresholdN (original keygen parties).
This fixes the "U doesn't equal T" error in round 9 when doing 3-of-5
co-managed signing with parties at indices 2,3,4.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
When switching message/event streams, the old stream's 'end' or 'error'
events could fire after the new stream was created. Since activeMessageSubscription
was already updated to the new session, the old stream's events would
incorrectly trigger reconnection, causing TSS message routing to fail.
Fix:
- Remove event listeners from old stream before canceling
- Use closure to capture current stream reference
- Check if event is from current active stream before triggering reconnect
This fixes the "Not connected" error during co-sign TSS message routing.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
- Keygen/co-keygen: must have exactly N participants joined
- Sign (co-sign/persistent): only check all registered participants joined
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
User says 3-of-5 meaning 3 signers needed, but tss-lib threshold t means t+1 signers.
Pass thresholdT-1 so tss-lib needs (t-1)+1 = t signers, matching user expectation.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Reverts e81757ad - the threshold conversion was wrong.
Keygen works with original thresholdT/thresholdN parameters.
The signing issue needs a different fix.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
- Rename thresholdT/thresholdN to requiredSigners/totalParties in Create.tsx
- Add parameter conversion in main.ts: threshold_t = requiredSigners - 1
- In tss-lib, threshold t means t+1 parties needed to sign
- For 3-of-5: requiredSigners=3 → threshold_t=2 (t+1=3 signers)
- externalCount = requiredSigners (user parties)
- persistentCount = totalParties - requiredSigners (server parties)
- Backward compatible with legacy thresholdT/thresholdN format
BREAKING: Existing co-managed wallets need re-keygen with new params
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
The TSS signing was failing with "U doesn't equal T" error because
tss-party was passing incorrect parameters to tss.NewParameters():
- Was: len(sortedPartyIDs)=3 (signing participants), thresholdT-1=2
- Now: thresholdN=5 (keygen N), thresholdT=3 (keygen T)
This matches how pkg/tss/signing.go creates parameters in server-party,
which uses TotalParties=N and Threshold=T from the original keygen.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Add keygenThresholdN to the CreateSignSession response so frontend
can access the original N value from keygen session. This is required
for proper TSS operation.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Add detailed comments to warn about changes that affect persistent sign flow:
- session_coordinator.go: ValidateSessionCreation now allows T <= count <= N for sign
- mpc_session.go: CanStart/AllPartiesReady now check registered participants, not N
- session_coordinator_client.go: ThresholdN now uses keygenThresholdN instead of len(parties)
Each comment includes:
- Original code behavior
- New code behavior
- How to revert if persistent sign breaks
- Related files list
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
- Change ValidateSessionCreation to accept T <= participantCount <= N for sign sessions
- Co-managed sign uses exactly T parties
- Persistent sign uses T+1 parties
- Both now pass validation with correct keygenThresholdN
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
- CanStart(): Check if all registered participants have joined, not based on T/N
- AddParticipant(): Keep N as max limit (API handles T vs T+1 validation)
- AllPartiesReady(): Check all registered participants, not based on T/N
- This approach works for both co-managed (T parties) and persistent (T+1 parties) signing
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
- For keygen sessions: require all N parties to join before starting
- For sign sessions: require only T parties to join before starting
- This fixes session_started event not being triggered for signing sessions
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
- Modify ValidateSessionCreation to differentiate between keygen and sign sessions
- For keygen: require participantCount == threshold.N() (all parties must participate)
- For sign: require participantCount == threshold.T() (only t parties needed)
- This fixes "session is full" error when creating signing session with 3 parties but n=5
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
- Query keygen session from mpc_sessions table to get correct threshold_n
- Pass keygenThresholdN to CreateSigningSessionAuto instead of len(parties)
- Return parties list and correct threshold values in GetSignSessionByInviteCode
- This fixes TSS signing failure "U doesn't equal T" caused by mismatched n values
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Problem: Participants joining early only got incomplete participant list
from other_parties (only those who had joined), causing partyIndex mismatch.
Solution:
- Add parties field to SessionInfo (from validateInviteCode response)
- Pass parties to joinSession call from frontend
- Backend joinSession uses params.parties (complete list) instead of
result.other_parties (incomplete list)
- Add debug logging to track participant list state
Now all participants have the complete parties list with correct partyIndex.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
- Add logic in handleCoSignStart to update participants from event.selectedParties
- Fix initiator immediate trigger to use other_parties + self instead of incomplete participants list
- Add debug logging for participant list updates
- Ensures all parties have correct participant list before TSS signing starts
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Change /sign to /cosign/join so participants use the correct page
with auto-join functionality.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Add console.log statements to trace the auto-join logic:
- Log loaded shares with sessionId
- Log auto-select share matching check
- Log auto-join conditions and share match status
- Log validateInviteCode results including joinToken
- Log handleJoinSession parameters
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
When multiple sign sessions share the same invite code (due to retries),
the query now:
1. Excludes failed sessions (status != 'failed')
2. Orders by created_at DESC to get the most recent session
3. Limits to 1 result
This prevents participants from seeing an old failed session's status
when they look up the invite code.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
The validateSigningSession handler was using parties.length for threshold.n
which returned 0 when parties array was empty. Now correctly uses the
threshold_n value returned from the backend API.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Password is optional - remove the validation that required password
to be non-empty before joining a sign session.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Password field was required to enable the join button, but password
is optional when the share was created without encryption.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
- Add threshold_n to GetSignSessionByInviteCodeResponse interface
- Fix main.ts to use result.threshold_n instead of result.parties?.length
- Add message_hash, joined_count, join_token to GetSignSessionByInviteCode response
- Generate join token for sign session lookup
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
- Add invite_code retrieval in GetSignSessionStatus (backend)
- Add inviteCode to cosign:getSessionStatus response (frontend IPC)
- Add inviteCode to SessionState and display UI in CoSignSession
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
- Fetch keygen session status from backend to get accurate party_index
- Filter out co-managed-party-* (server persistent parties) from signing
- Only temporary/external user parties participate in signing
- For 3-of-5 wallet: 3 user parties sign, 2 co-managed parties are backup only
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
- Use API's participants field instead of parties
- Use API's threshold_t and threshold_n instead of activeCoSignSession
- Show participant status from API response
- Update GetSignSessionStatusResponse interface
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
- Add join_tokens (map[partyID]token) to CreateSignSession response
- Keep join_token for backward compatibility
- Update frontend to use join_tokens[partyId] for initiator auto-join
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
BigInt cannot be serialized by JSON.stringify. Convert gasLimit,
maxFeePerGas, maxPriorityFeePerGas, and value to strings before
storing in sessionStorage.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Add complete co-sign functionality for multi-party transaction signing:
Frontend (React):
- CoSignCreate.tsx: Create signing session with share selection
- CoSignJoin.tsx: Join signing session via invite code
- CoSignSession.tsx: Monitor signing progress and results
- Add routes in App.tsx for new pages
Backend (Electron):
- main.ts: Add IPC handlers for co-sign operations
- tss-handler.ts: Add participateSign() for TSS signing
- preload.ts: Expose cosign API to renderer
- account-client.ts: Add sign session API types
TSS Party (Go):
- main.go: Implement 'sign' command for GG20 signing protocol
- integration_test.go: Add comprehensive tests for signing flow
Infrastructure:
- docker-compose.windows.yml: Expose gRPC port 50051
This is a pure additive change that does not affect existing
persistent role keygen/sign functionality.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
- Add KAVA_TESTNET_TX_CONFIG in kava-tx-service.ts
- Add switchNetwork/getNetwork IPC handlers in main.ts
- Add network toggle UI in Settings page
- Show current network (测试网/主网) badge in Layout status bar
- Default to testnet for development
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
listShares returned `participants` but Home.tsx expected `metadata.participants`
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Default 64KB buffer was truncating large TSS protocol messages in round 3+
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
session_created event only contains initial co-managed parties,
but session_started event contains ALL participants including
external parties that joined dynamically via invite code.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Add new ExecuteWithSessionInfo method to ParticipateKeygenUseCase
for server-party-co-managed to skip duplicate JoinSession call.
- server-party-co-managed already calls JoinSession in session_created phase
- ExecuteWithSessionInfo accepts pre-obtained SessionInfo and skips internal JoinSession
- Refactor common execution logic to private executeWithSessionInfo method
- Update server-party-co-managed to use ExecuteWithSessionInfo on session_started
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
- Create new server-party-co-managed service with two-phase event handling
- Phase 1 (session_created): Store join token and wait
- Phase 2 (session_started): Execute TSS protocol (same timing as service-party-app)
- Add PartyRoleCoManagedPersistent role to isolate from normal keygen/sign
- Update docker-compose.yml with 3 co-managed party instances
- Update deploy.sh service lists
- Modify selectPartiesByCompositionForCoManaged to use new role
This ensures co_managed_keygen sessions use dedicated parties that behave
100% compatible with service-party-app, without affecting existing keygen/sign flows.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Problem:
- co_managed_keygen server-party waits for external party after joining
- No heartbeat sent during wait period (up to 5 minutes)
- session-coordinator has 120 second inactivity timeout
- Server-party marked as timed_out/failed while waiting
Fix:
- Send heartbeat in waitForAllParticipants polling loop
- Add Heartbeat method to MessageRouterClient interface
- Heartbeat every 2 seconds with poll interval
- Heartbeat failure only logs warning, does not block
Generated with Claude Code
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
- expires_at 存储为 UTC 时间
- 查询时使用 NOW() AT TIME ZONE 'UTC' 确保时区一致
- 避免因时区差异导致 session 过早被标记为过期
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
api.szaiai.com 被 OSS/CDN 拦截,改用 rwaapi.szaiai.com 直接访问 Kong 网关
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
添加 50051:50051 端口映射,使开发模式与生产模式保持一致
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
将 proto 文件加载改为延迟加载模式,在 connect() 时才加载,
避免模块加载时 app.isPackaged 还未准备好导致的路径错误。
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>