This release adds 3 notable features for engineering teams evaluating rollout.
✓ No known CVEs patched in this version
ReleasePort's take
Light signalVersion v0.19.0 of Mistle introduces numerous new features and restores critical functionality while addressing several bugs.
Why it matters: Patch to v0.19.0 immediately to regain Pi chat, re‑enable API key revocation, and invalidate stale gateway credentials; plan migrations for added composer slash commands, session deletion, and sandbox memory limits.
Summary
AI summaryUpdates 0.19.0] - 2026-05-21, Refactors, and Bug Fixes across a mixed release.
Changes in this release
| Type | Severity | Summary | CVE |
|---|---|---|---|
| Feature | Medium |
Add composer slash commands for streamlined prompt composition. Add composer slash commands for streamlined prompt composition. Source: granite4.1:30b@2026-05-21-audit Confidence: high |
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| Feature | Medium |
Support deleting sessions for improved session lifecycle management. Support deleting sessions for improved session lifecycle management. Source: granite4.1:30b@2026-05-21-audit Confidence: high |
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| Feature | Medium |
Show original codex thread metadata in UI. Show original codex thread metadata in UI. Source: granite4.1:30b@2026-05-21-audit Confidence: high |
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| Feature | Medium |
Add mistle CLI update command for easier CLI management. Add mistle CLI update command for easier CLI management. Source: granite4.1:30b@2026-05-21-audit Confidence: high |
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| Feature | Medium |
Add Pi to session chat workbench and enable attachment parity. Add Pi to session chat workbench and enable attachment parity. Source: granite4.1:30b@2026-05-21-audit Confidence: high |
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| Feature | Medium |
Scaffold mistle MCP server and profile infrastructure. Scaffold mistle MCP server and profile infrastructure. Source: granite4.1:30b@2026-05-21-audit Confidence: high |
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| Feature | Medium |
Scaffold file search stream protocol and implement support. Scaffold file search stream protocol and implement support. Source: granite4.1:30b@2026-05-21-audit Confidence: high |
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| Feature | Medium |
Enable codex goal and review composer commands. Enable codex goal and review composer commands. Source: granite4.1:30b@2026-05-21-audit Confidence: high |
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| Feature | Medium |
Scaffold control plane MCP endpoint with auth and profile tools. Scaffold control plane MCP endpoint with auth and profile tools. Source: granite4.1:30b@2026-05-21-audit Confidence: high |
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| Feature | Medium |
Add pi model selection and runtime conversation navigator. Add pi model selection and runtime conversation navigator. Source: granite4.1:30b@2026-05-21-audit Confidence: high |
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| Feature | Medium |
Detect and report dashboard build drift issues. Detect and report dashboard build drift issues. Source: granite4.1:30b@2026-05-21-audit Confidence: high |
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| Feature | Medium |
Add sandbox usage events table and event writer. Add sandbox usage events table and event writer. Source: granite4.1:30b@2026-05-21-audit Confidence: high |
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| Feature | Medium |
Add gateway MCP token auth and credential injection. Add gateway MCP token auth and credential injection. Source: granite4.1:30b@2026-05-21-audit Confidence: high |
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| Feature | Medium |
Add Codex plan command and authenticate control plane tokens. Add Codex plan command and authenticate control plane tokens. Source: granite4.1:30b@2026-05-21-audit Confidence: high |
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| Feature | Medium |
Allow and manage multiple identity link provider configurations. Allow and manage multiple identity link provider configurations. Source: granite4.1:30b@2026-05-21-audit Confidence: high |
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| Feature | Medium |
Add one-off schedule support with CRUD and dispatch workflow. Add one-off schedule support with CRUD and dispatch workflow. Source: granite4.1:30b@2026-05-21-audit Confidence: high |
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| Feature | Medium |
Add composer context mentions feature. Add composer context mentions feature. Source: granite4.1:30b@2026-05-21-audit Confidence: high |
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| Feature | Medium |
Link accounts by provider config and select credentials by connection. Link accounts by provider config and select credentials by connection. Source: granite4.1:30b@2026-05-21-audit Confidence: high |
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| Feature | Medium |
Add MCP profile setup script tool and test tools. Add MCP profile setup script tool and test tools. Source: granite4.1:30b@2026-05-21-audit Confidence: high |
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| Feature | Medium |
Expose sandbox context to agents. Expose sandbox context to agents. Source: granite4.1:30b@2026-05-21-audit Confidence: high |
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| Feature | Medium |
Support opencode prompt commands. Support opencode prompt commands. Source: granite4.1:30b@2026-05-21-audit Confidence: high |
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| Feature | Medium |
Select git signing connection for sandbox profiles. Select git signing connection for sandbox profiles. Source: granite4.1:30b@2026-05-21-audit Confidence: high |
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| Feature | Medium |
Surface external setup script updates in UI. Surface external setup script updates in UI. Source: granite4.1:30b@2026-05-21-audit Confidence: high |
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| Feature | Medium |
Support bounded sandboxd stdin payloads. Support bounded sandboxd stdin payloads. Source: granite4.1:30b@2026-05-21-audit Confidence: high |
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| Feature | Medium |
Duplicate sandbox profiles for easy configuration reuse. Duplicate sandbox profiles for easy configuration reuse. Source: granite4.1:30b@2026-05-21-audit Confidence: high |
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| Feature | Medium |
Support GitHub app installation selection. Support GitHub app installation selection. Source: granite4.1:30b@2026-05-21-audit Confidence: high |
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| Performance | Medium |
Raise e2b sandbox memory capacity limit to 16GB. Raise e2b sandbox memory capacity limit to 16GB. Source: granite4.1:30b@2026-05-21-audit Confidence: high |
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| Bugfix | Medium |
Re-enable API key revoke actions functionality. Re-enable API key revoke actions functionality. Source: granite4.1:30b@2026-05-21-audit Confidence: high |
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| Bugfix | Medium |
Restore Pi chat functionality after TUI handoff. Restore Pi chat functionality after TUI handoff. Source: granite4.1:30b@2026-05-21-audit Confidence: high |
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| Bugfix | Medium |
Invalidate gateway credential cache on connection updates. Invalidate gateway credential cache on connection updates. Source: granite4.1:30b@2026-05-21-audit Confidence: high |
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Full changelog
[0.19.0] - 2026-05-21
Features
- Add composer slash commands (#2245)
- Support deleting sessions (#2255)
- Show original codex thread metadata (#2256)
- Add mistle cli update command (#2253)
- Add Pi to session chat workbench (#2257)
- Scaffold mistle mcp server (#2266)
- Scaffold file search stream protocol (#2268)
- Add Pi attachment and follow-up parity (#2271)
- Scaffold file search stream in sandboxd (#2272)
- Add mcp profile tools (#2270)
- Enable codex goal composer command (#2274)
- Add fff file search stream support (#2275)
- Scaffold control plane MCP endpoint (#2276)
- Add pi model selection (#2278)
- Add runtime conversation navigator (#2280)
- Add control plane MCP profile tools (#2281)
- Detect dashboard build drift (#2279)
- Add control plane MCP auth config (#2285)
- Add sandbox usage events table (#2289)
- Add gateway MCP token auth (#2290)
- Add Codex plan command (#2288)
- Authenticate control plane MCP tokens (#2295)
- Add pi runtime conversation navigator (#2296)
- Add sandbox usage event writer (#2298)
- Expose identity link provider config ids (#2300)
- Add profile version MCP schema (#2301)
- Record sandbox usage events from worker workflows (#2306)
- Allow multiple identity link provider configs (#2305)
- Configure Mistle MCP runtime plans (#2310)
- Add codex review composer command (#2314)
- Add Mistle MCP profile toggle (#2316)
- Support opencode prompt commands (#2323)
- Add config-level identity link provider management (#2318)
- Inject mistle mcp credentials through gateway (#2327)
- Add composer context mentions (#2330)
- Raise e2b memory cap to 16gb (#2335)
- Link accounts by provider config (#2329)
- Add mcp profile setup script tool (#2337)
- Expose sandbox context to agents (#2340)
- Update setup assistant mcp guidance (#2344)
- Add mcp setup script test tools (#2347)
- Prepare schedules for one-off runs (#2346)
- Surface external setup script updates (#2351)
- Add one-off schedule dispatch workflow (#2353)
- Support bounded sandboxd stdin payloads (#2358)
- Select linked principal credentials by connection (#2342)
- Select git signing connection for sandbox profiles (#2350)
- Wire one-off schedule CRUD (#2362)
- Label multi-config identity links (#2355)
- Scope setup assistant mistle mcp access (#2360)
- Support negative trigger event parameters (#2371)
- Add maintenance script mcp tools (#2375)
- Sync maintenance assistant mcp updates (#2380)
- Add sandbox resume visibility (#2383)
- Duplicate sandbox profiles (#2388)
- Support GitHub app installation selection (#2387)
Bug Fixes
- Ignore unknown sandbox protocol fields (#2267)
- Reject duplicate sandbox tunnel stream opens (#2283)
- Clean up reset tunnel stream state (#2284)
- Improve signoz connection region selection (#2287)
- Refine pi composer controls (#2299)
- Clarify setup assistant draft startup (#2303)
- Preserve snapshot refresh edits for setup assistant (#2308)
- Refine maintenance assistant prompt (#2312)
- Stabilize dashboard build drift snapshot (#2313)
- Hide Pi tool-call assistant messages (#2317)
- Preserve auth invite error payloads (#2319)
- Generate pi sandbox session titles (#2322)
- Prepublish system test sandbox image (#2336)
- Re-enable api key revoke actions (#2339)
- Track pi rpc process readiness (#2341)
- Track opencode server readiness (#2343)
- Recover sandboxd runtime process coordination (#2357)
- Keep sessions search list mounted (#2364)
- Run tensorlake sandboxd maintenance through sudo (#2365)
- Restore Pi chat after TUI handoff (#2366)
- Invalidate gateway credential cache on connection updates (#2361)
- Attribute sandbox startup events to phases (#2368)
- Decode setup assistant mcp tokens in sandboxd (#2370)
- Show resolved github signing connection (#2373)
- Handle inaccessible resource links (#2372)
- Handle stateless github app setup callbacks (#2381)
- Redirect provider app setup state errors (#2385)
- Run Tensorlake sandbox commands as root (#2389)
Refactors
- Generalize workbench conversation naming (#2269)
- Remove CLI MCP server (#2282)
- Move tunnel session file upload state (#2286)
- Move tunnel session agent stream state (#2291)
- Move tunnel session telemetry helpers (#2293)
- Move tunnel session file search state (#2297)
- Move port access session state (#2302)
- Move port access routing (#2304)
- Move port access control handling (#2307)
- Remove storage usage event types (#2309)
- Move operation stream handling (#2311)
- Move gateway request handling (#2315)
- Extract process stream session handling (#2321)
- Scope agent stream session handling (#2324)
- Split sandboxd session gateway request handling (#2325)
- Extract sandboxd session exec and pty handling (#2326)
- Extract sandboxd session bootstrap handling (#2328)
- Split sandboxd tunnel session modules (#2331)
- Colocate sandboxd session unit tests (#2332)
- Split sandboxd session workflow tests (#2333)
- Split sandboxd session router (#2334)
- Split sandboxd module hotspots (#2338)
- Split pi proxy internals (#2348)
- Split sandboxd structural helpers (#2354)
- Split sandboxd opencode proxy module (#2359)
- Split egress proxy infrastructure (#2363)
- Split sandboxd state facade (#2367)
- Split codex proxy session module (#2378)
- Split sandboxd control module (#2382)
- Split sandboxd egress proxy module (#2384)
- Split codex proxy facade (#2386)
- Split codex session manager modules (#2390)
Documentation
- Require setup assistant validation before saving (#2352)
- Move CLI install notes (#2374)
Tests
- Stabilize operation stream close flush (#2320)
- Cover multi-config webhook attribution (#2356)
Chores
- Bump codex cli to 0.132.0 (#2277)
- Rename sandbox usage event types (#2292)
- Add sandbox resumed usage event type (#2294)
- (deps) Bump @opentelemetry/sdk-metrics to 2.7.1
- (deps) Bump @tailwindcss/vite to 4.3.0
- Add fd to sandbox base image (#2345)
- Update jsx-email to v3 (#2369)
- (release) V0.19.0 (#2391)
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