fix(gateway): support Streamable HTTP MCP transport on loopback server#89851
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Codex review: needs maintainer review before merge. Reviewed June 7, 2026, 5:07 AM ET / 09:07 UTC. Summary PR surface: Source +57, Tests +87. Total +144 across 2 files. Reproducibility: yes. Current main can be reproduced from source by starting the loopback MCP server and sending GET Review metrics: 2 noteworthy metrics.
Merge readiness Overall follows the weaker of proof and patch quality, so missing proof can cap an otherwise strong patch. Rank-up moves:
Risk before merge
Maintainer options:
Next step before merge
Security Review detailsBest possible solution: Land the narrow GET SSE and stateless DELETE behavior only after a gateway/MCP owner accepts the stateless/security contract and final-head gateway tests or CI confirm it composes with current main. Do we have a high-confidence way to reproduce the issue? Yes. Current main can be reproduced from source by starting the loopback MCP server and sending GET Is this the best way to solve the issue? Yes for the missing GET SSE behavior; it is the narrowest fix for the reported hang. The stateless no-session and DELETE no-op parts are acceptable only if a gateway/MCP owner explicitly accepts that as the loopback contract. AGENTS.md: found and applied where relevant. Codex review notes: model gpt-5.5, reasoning high; reviewed against e06f6ffc3e87. Label changesLabel justifications:
Evidence reviewedPR surface: Source +57, Tests +87. Total +144 across 2 files. View PR surface stats
What I checked:
Likely related people:
What the crustacean ranks mean
Shiny media proof means a screenshot, video, or linked artifact directly shows the changed behavior. Runtime, network, CSP, and security claims still need visible diagnostics. How this review workflow works
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@clawsweeper re-review |
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🦞🧹 I asked ClawSweeper to review this item again. Re-review progress:
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@clawsweeper re-review |
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🦞🧹 I asked ClawSweeper to review this item again. Re-review progress:
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@clawsweeper re-review |
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🦞🧹 I asked ClawSweeper to review this item again. Re-review progress:
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Addressed the review:
On the [P1] real-behavior proof: the transport (GET notification channel returning 200+SSE instead of the 405 that caused the hang) is exercised over real HTTP in the tests above. The full live Claude Code "MCP tools connect" run is contributor-setup proof — the agent runtime's private deps resolve only in the build environment, so it can't be produced from a plain source checkout — and will be attached from a patched OpenClaw + Claude Code session. @clawsweeper re-review |
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🦞🧹 I asked ClawSweeper to review this item again. Re-review progress:
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Added real-behavior proof: built and started the patched loopback MCP server and hit it with curl — GET (valid bearer) returns 200 + text/event-stream (the SSE notification channel; curl then blocks on the open stream, not the old 405 that hung "still connecting"); GET no-auth → 401; GET browser-origin → 403; DELETE → 200; DELETE no-auth → 401; PUT → 405 with |
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🦞👀 Command router queued. I will update this comment with the next step. |
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Addressed both code findings:
84 gateway tests pass. The stateless no- |
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🦞👀 Command router queued. I will update this comment with the next step. |
…rt) onto combined branch The agent's MCP loopback client opens a GET/SSE notification channel; without openclaw#89851's GET/SSE handling the loopback server 405s it and the agent turn hangs after tool-policy, before the model call. Porting openclaw#89851 (GET/SSE + DELETE no-op + origin-before-auth, stateless) so the loopback completes and a live agent turn can actually stream — needed for the streaming echo capture. 3-way applied clean.
The MCP loopback server generates config with `"type": "http"` for Claude Code, but only handled POST requests. Claude Code's Streamable HTTP client sends GET to open an SSE notification channel before completing initialization. The 405 rejection on GET caused Claude Code to hang at "still connecting" indefinitely. - Accept GET /mcp with bearer auth, return text/event-stream (idle SSE) - Accept DELETE /mcp for session termination (spec compliance) - Add Mcp-Session-Id header to POST responses (spec requirement) - Update 405 Allow header to reflect supported methods
…check - flushHeaders() + initial SSE comment so clients don't hang - DELETE requires bearer auth (matching GET/POST gates) - DELETE checks browser-origin rejection (matching POST gate)
…o terminate The DELETE path acknowledged Mcp-Session-Id without validating, terminating, or expiring anything. Since the loopback server is stateless (session ID is cosmetic for spec compliance), return 405 instead of pretending to support session teardown.
…rt tests Addresses review feedback on the Streamable HTTP transport: - Keep the loopback server stateless: drop the advertised Mcp-Session-Id header (the server owns no session lifecycle, so advertising a session id clients would echo back was misleading). Resolves the stateless-vs-sessionful concern. - Add DELETE /mcp as an auth-gated 200 no-op (Streamable HTTP teardown), so clients that send DELETE on close get a clean 200 instead of 405; Allow now advertises GET, POST, DELETE. - Keep the GET/SSE notification channel (the actual fix for the 'still connecting' hang) auth-gated and browser-origin-rejected. - Add focused gateway tests: GET 200 + text/event-stream, GET 401 (no auth), GET 403 (browser origin), DELETE 200, DELETE 401, unsupported 405 with the correct Allow, and POST stays stateless (no Mcp-Session-Id).
…est token Addresses review: - Reorder the new GET and DELETE branches so rejectsBrowserLoopbackRequest() runs BEFORE bearer auth, matching the POST path — a browser-Origin loopback request is now rejected (403) before auth, preserving the loopback Origin boundary even for unauthenticated browser requests. Added focused tests: browser-Origin GET and DELETE with no bearer return 403 (before auth). - The new transport tests now read the loopback owner token from getActiveMcpLoopbackRuntime().ownerToken instead of resolveMcpLoopbackBearerToken, so they don't depend on that helper's import (which current main's test file no longer carries).
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Merged using rebase. What landed:
Verification:
Thanks @anagnorisis2peripeteia. |
…26.6.6) (#1040) This PR contains the following updates: | Package | Update | Change | |---|---|---| | [ghcr.io/openclaw/openclaw](https://openclaw.ai) ([source](https://github.com/openclaw/openclaw)) | patch | `2026.6.5` → `2026.6.6` | --- ### Release Notes <details> <summary>openclaw/openclaw (ghcr.io/openclaw/openclaw)</summary> ### [`v2026.6.6`](https://github.com/openclaw/openclaw/blob/HEAD/CHANGELOG.md#202666) [Compare Source](openclaw/openclaw@v2026.6.5...v2026.6.6) ##### Highlights - Security boundaries are substantially tighter across transcripts, sandbox binds, host environment inheritance, MCP stdio, Codex HTTP access, native search policy, elevated sender checks, deleted-agent ACP bypasses, loopback tools, Discord moderation, and Teams group actions; exec approvals now fail closed on timeout. ([#​91529](openclaw/openclaw#91529), [#​91618](openclaw/openclaw#91618), [#​91615](openclaw/openclaw#91615), [#​91619](openclaw/openclaw#91619), [#​91741](openclaw/openclaw#91741), [#​91745](openclaw/openclaw#91745), [#​91746](openclaw/openclaw#91746), [#​91748](openclaw/openclaw#91748), [#​91749](openclaw/openclaw#91749), [#​91750](openclaw/openclaw#91750), [#​91751](openclaw/openclaw#91751), [#​91752](openclaw/openclaw#91752), [#​91763](openclaw/openclaw#91763), [#​89938](openclaw/openclaw#89938)) Thanks [@​joshavant](https://github.com/joshavant), [@​pgondhi987](https://github.com/pgondhi987), [@​mmaps](https://github.com/mmaps), [@​eleqtrizit](https://github.com/eleqtrizit), [@​shakkernerd](https://github.com/shakkernerd), and [@​drobison00](https://github.com/drobison00). - Telegram delivery is safer and more coherent: account-scoped topics route to the right agent, streamed text survives tool calls, `/compact` works on generic ingress, callback handling uses concrete APIs, draft chunking is shared, durable dispatch dedupe moved into the SDK, and unauthorized DM text stays out of cache and prompt context. ([#​91189](openclaw/openclaw#91189), [#​88682](openclaw/openclaw#88682), [#​89588](openclaw/openclaw#89588), [#​90212](openclaw/openclaw#90212), [#​91876](openclaw/openclaw#91876), [#​91874](openclaw/openclaw#91874), [#​91904](openclaw/openclaw#91904), [#​91478](openclaw/openclaw#91478), [#​91915](openclaw/openclaw#91915)) Thanks [@​codysai001](https://github.com/codysai001), [@​alexzhu0](https://github.com/alexzhu0), [@​joelnishanth](https://github.com/joelnishanth), [@​snowzlm](https://github.com/snowzlm), [@​obviyus](https://github.com/obviyus), and [@​sallyom](https://github.com/sallyom). - iMessage recovery and delivery now cover always-on inbound restart, durable echo markers, block streaming, idle approval discovery, hardened outbound transport, and actionable inbound startup diagnostics. ([#​91335](openclaw/openclaw#91335), [#​91449](openclaw/openclaw#91449), [#​88969](openclaw/openclaw#88969), [#​88530](openclaw/openclaw#88530), [#​91783](openclaw/openclaw#91783), [#​91785](openclaw/openclaw#91785)) Thanks [@​omarshahine](https://github.com/omarshahine), [@​jmissig](https://github.com/jmissig), and [@​colmbrogan](https://github.com/colmbrogan). - Browser and MCP connectivity gained existing-session CDP support, discovered WebSocket validation, default-profile `cdpUrl` handling, safer browser-output boundaries, Streamable HTTP loopback transport, corrected OAuth/SSE authorization handling, and broader schema compatibility. ([#​91422](openclaw/openclaw#91422), [#​89851](openclaw/openclaw#89851), [#​91736](openclaw/openclaw#91736), [#​91747](openclaw/openclaw#91747), [#​91451](openclaw/openclaw#91451), [#​80143](openclaw/openclaw#80143)) Thanks [@​pgondhi987](https://github.com/pgondhi987), [@​anagnorisis2peripeteia](https://github.com/anagnorisis2peripeteia), [@​lifuyue](https://github.com/lifuyue), [@​eleqtrizit](https://github.com/eleqtrizit), [@​LiuwqGit](https://github.com/LiuwqGit), and [@​HemantSudarshan](https://github.com/HemantSudarshan). - Control UI startup and first-reply latency are lower through cached model metadata, removal of the startup catalog wait, lazy slash-command loading, and first-event tracing with slow-reply diagnostics. ([#​91531](openclaw/openclaw#91531), [#​91538](openclaw/openclaw#91538), [#​91568](openclaw/openclaw#91568), [#​91583](openclaw/openclaw#91583), [#​91598](openclaw/openclaw#91598)) - Provider support expands with OpenRouter OAuth onboarding and Claude Fable 5 adaptive thinking, while Codex sessions keep correct compaction ownership, local models skip guardian review, dynamic tool progress normalizes cleanly, and Gemma 4 reasoning replay is preserved. ([#​91830](openclaw/openclaw#91830), [#​91882](openclaw/openclaw#91882), [#​91590](openclaw/openclaw#91590), [#​88630](openclaw/openclaw#88630), [#​88768](openclaw/openclaw#88768), [#​91696](openclaw/openclaw#91696)) Thanks [@​Patrick-Erichsen](https://github.com/Patrick-Erichsen), [@​joshavant](https://github.com/joshavant), [@​bdjben](https://github.com/bdjben), and [@​Coder-Wangyankun](https://github.com/Coder-Wangyankun). ##### Changes - CLI progress: emit Claude CLI commentary progress events and bridge inter-tool commentary into channel progress without exposing internal protocol scaffolding. ([#​89834](openclaw/openclaw#89834), [#​90883](openclaw/openclaw#90883)) Thanks [@​anagnorisis2peripeteia](https://github.com/anagnorisis2peripeteia). - Observability: allow trusted diagnostics channels to capture tool input/output content, add first-assistant-event traces, and warn on slow initial replies. ([#​91256](openclaw/openclaw#91256), [#​91568](openclaw/openclaw#91568), [#​91583](openclaw/openclaw#91583)) Thanks [@​amknight](https://github.com/amknight). - Plugins/ClawHub: dogfood reusable package publishing, let dry runs skip publish approval, allow declared installed trusted hooks, report managed plugin version drift, and warn instead of failing on retired Skill Workshop configuration. ([#​91574](openclaw/openclaw#91574), [#​91591](openclaw/openclaw#91591), [#​90004](openclaw/openclaw#90004), [#​90927](openclaw/openclaw#90927), [#​90838](openclaw/openclaw#90838)) Thanks [@​Patrick-Erichsen](https://github.com/Patrick-Erichsen), [@​brokemac79](https://github.com/brokemac79), and [@​lonexreb](https://github.com/lonexreb). - Memory/providers: move the local llama.cpp runtime into its provider plugin, batch embeddings across files, persist the agent model catalog cache, and keep QMD JSON search one-shot while filtering stale REM recall previews. ([#​91324](openclaw/openclaw#91324), [#​89138](openclaw/openclaw#89138), [#​90457](openclaw/openclaw#90457), [#​91837](openclaw/openclaw#91837), [#​91851](openclaw/openclaw#91851)) Thanks [@​osolmaz](https://github.com/osolmaz), [@​mushuiyu886](https://github.com/mushuiyu886), [@​ai-hpc](https://github.com/ai-hpc), and [@​TurboTheTurtle](https://github.com/TurboTheTurtle). - Channels/mobile: add the QQBot group mention toggle, improve iPad and iPhone control surfaces, and expose the active connection host in the TUI footer. ([#​91423](openclaw/openclaw#91423), [#​91557](openclaw/openclaw#91557), [#​89909](openclaw/openclaw#89909)) Thanks [@​cxyhhhhh](https://github.com/cxyhhhhh), [@​Solvely-Colin](https://github.com/Solvely-Colin), and [@​baskduf](https://github.com/baskduf). - Performance: prewarm TUI runtime plugins, deduplicate plugin auto-enable fanout, trim dense text-delta snapshots, and reuse prepared startup model metadata. ([#​90782](openclaw/openclaw#90782), [#​89978](openclaw/openclaw#89978), [#​91580](openclaw/openclaw#91580), [#​91531](openclaw/openclaw#91531)) Thanks [@​RomneyDa](https://github.com/RomneyDa) and [@​ai-hpc](https://github.com/ai-hpc). ##### Fixes - Agent/session recovery: drop stale approval follow-ups after session rebind, remove drained reply-queue items by identity, recover stale main and visible replies, preserve Codex context-engine compaction ownership, lower the default compaction timeout to 180 seconds while respecting explicit configuration, and keep provider-failure terminal lifecycle state correct. ([#​85679](openclaw/openclaw#85679), [#​91450](openclaw/openclaw#91450), [#​91566](openclaw/openclaw#91566), [#​91840](openclaw/openclaw#91840), [#​91590](openclaw/openclaw#91590), [#​91361](openclaw/openclaw#91361), [#​91895](openclaw/openclaw#91895)) Thanks [@​openperf](https://github.com/openperf), [@​yetval](https://github.com/yetval), [@​joshavant](https://github.com/joshavant), [@​wangmiao0668000666](https://github.com/wangmiao0668000666), and [@​TurboTheTurtle](https://github.com/TurboTheTurtle). - User-visible content boundaries: suppress Codex/Harmony protocol artifacts, neutralize browser and LanceDB memory media directives, redact transcript images, and preserve native `/compact` replies through source suppression. ([#​89151](openclaw/openclaw#89151), [#​91422](openclaw/openclaw#91422), [#​91425](openclaw/openclaw#91425), [#​91529](openclaw/openclaw#91529), [#​90212](openclaw/openclaw#90212)) Thanks [@​joelnishanth](https://github.com/joelnishanth), [@​pgondhi987](https://github.com/pgondhi987), [@​joshavant](https://github.com/joshavant), and [@​snowzlm](https://github.com/snowzlm). - Channel delivery: keep WhatsApp captured replies attached to the successor controller after restart, retry Feishu rate limits, preserve Mattermost thread replies, canonicalize LINE webhook paths, restore Discord reply hydration and runtime timeout exports, and show OpenAI Realtime WebRTC assistant transcripts. ([#​85823](openclaw/openclaw#85823), [#​89659](openclaw/openclaw#89659), [#​91684](openclaw/openclaw#91684), [#​91649](openclaw/openclaw#91649), [#​90263](openclaw/openclaw#90263), [#​91686](openclaw/openclaw#91686), [#​90426](openclaw/openclaw#90426)) Thanks [@​itsuzef](https://github.com/itsuzef), [@​ladygege](https://github.com/ladygege), [@​jacobtomlinson](https://github.com/jacobtomlinson), [@​fuller-stack-dev](https://github.com/fuller-stack-dev), and [@​shushushv](https://github.com/shushushv). - Cron: cancel active task runs cleanly, preserve terminal timeout/cancel state, and recover no-deliver tool warnings instead of silently losing the outcome. ([#​90666](openclaw/openclaw#90666), [#​90678](openclaw/openclaw#90678)) Thanks [@​ai-hpc](https://github.com/ai-hpc). - Gateway/config/auth: share the approval runtime socket token, replace arrays explicitly in `config.patch`, skip the deleted-agent guard only for valid ACP harness sessions, surface headless LaunchAgent state, verify SQLite auth migration before cleanup, and arm QMD startup maintenance. ([#​87105](openclaw/openclaw#87105), [#​91551](openclaw/openclaw#91551), [#​91219](openclaw/openclaw#91219), [#​91614](openclaw/openclaw#91614), [#​91740](openclaw/openclaw#91740), [#​91978](openclaw/openclaw#91978)) Thanks [@​fuller-stack-dev](https://github.com/fuller-stack-dev) and [@​scotthuang](https://github.com/scotthuang). - Providers/Codex: clarify quota errors, restore the Codex synthetic usage line, canonicalize Codex protocol assets, require API-key auth for realtime voice, normalize ACP model refs, preserve Gemma 4 `reasoning_content`, and avoid guardian review for local models. ([#​91390](openclaw/openclaw#91390), [#​91709](openclaw/openclaw#91709), [#​91507](openclaw/openclaw#91507), [#​91567](openclaw/openclaw#91567), [#​88630](openclaw/openclaw#88630), [#​91696](openclaw/openclaw#91696)) Thanks [@​hxy91819](https://github.com/hxy91819), [@​brokemac79](https://github.com/brokemac79), [@​RomneyDa](https://github.com/RomneyDa), [@​joshavant](https://github.com/joshavant), and [@​Coder-Wangyankun](https://github.com/Coder-Wangyankun). - Updates/builds: recover package Gateway restarts after refresh failure, expose plugin convergence repair, fall back to Corepack in PATH-less pnpm environments, seed the correct Docker store packages, and keep ClawHub dry-run and publish paths reusable. ([#​91581](openclaw/openclaw#91581), [#​91599](openclaw/openclaw#91599), [#​91547](openclaw/openclaw#91547), [#​91591](openclaw/openclaw#91591)) Thanks [@​fuller-stack-dev](https://github.com/fuller-stack-dev), [@​sallyom](https://github.com/sallyom), and [@​Patrick-Erichsen](https://github.com/Patrick-Erichsen). - UI: require explicit user intent before opening chat sessions and drain restored chat queues after session switches. ([#​91480](openclaw/openclaw#91480)) Thanks [@​TurboTheTurtle](https://github.com/TurboTheTurtle). - Android: avoid the `dataSync` foreground-service type for persistent nodes. ([#​80082](openclaw/openclaw#80082)) Thanks [@​davelutztx](https://github.com/davelutztx). - Native hooks: bound relay lifetimes so abandoned native hook connections cannot linger indefinitely. ([#​91550](openclaw/openclaw#91550)) Thanks [@​joshavant](https://github.com/joshavant). </details> --- ### Configuration 📅 **Schedule**: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined). 🚦 **Automerge**: Disabled by config. Please merge this manually once you are satisfied. ♻ **Rebasing**: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox. 🔕 **Ignore**: Close this PR and you won't be reminded about these updates again. --- - [ ] <!-- rebase-check -->If you want to rebase/retry this PR, check this box --- This PR has been generated by [Renovate Bot](https://github.com/renovatebot/renovate). <!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiI0My4xMDEuMSIsInVwZGF0ZWRJblZlciI6IjQzLjEwMS4xIiwidGFyZ2V0QnJhbmNoIjoibWFpbiIsImxhYmVscyI6WyJyZW5vdmF0ZS9jb250YWluZXIiLCJ0eXBlL3BhdGNoIl19--> Reviewed-on: https://git.erwanleboucher.dev/eleboucher/homelab/pulls/1040
Summary
The MCP loopback HTTP server generates a config with
"type": "http"(Streamable HTTP transport), but only handled POST — a GET to/mcpreturned 405. Claude Code's Streamable HTTP client opens an SSE notification channel by sending GET/mcpduring initialization; the 405 left it hanging at "still connecting" indefinitely, so the agent got no OpenClaw MCP tools for the whole session.This adds the missing transport surface, kept stateless (the loopback server owns no session lifecycle):
/mcp→ 200text/event-stream— an auth-gated, browser-origin-rejected idle SSE notification channel (the actual fix for the hang). Closes cleanly when the client disconnects./mcp→ 200 — auth-gated no-op acknowledgement of Streamable HTTP session teardown, so clients that send DELETE on close get a clean 200 rather than 405.Mcp-Session-Id. The server processes each request independently; advertising a session id it never validates, expires, or owns would be misleading and push clients to echo a session the server ignores. (Per the spec, a stateless server simply omits the session id.)Allownow advertisesGET, POST, DELETE; other methods still 405.Session semantics
Resolved the stateless-vs-sessionful question in favor of stateless: a single-purpose local loopback tool endpoint has no session state to manage, so it stays stateless rather than taking on a session lifecycle. (Maintainer can revisit if sessionful semantics are ever wanted.)
Tests
src/gateway/mcp-http.test.ts— added focused gateway transport tests, all passing:text/event-streamOrigin→ 403Allow: GET, POST, DELETEMcp-Session-IdheaderReal behavior proof
Contributor curl proof from a built and running loopback MCP server also showed GET with a valid bearer returning 200 and Content-Type: text/event-stream, GET without auth returning 401, browser-Origin GET returning 403, authenticated DELETE returning 200, unauthenticated DELETE returning 401, and PUT returning 405 with Allow: GET, POST, DELETE.