{"record":{"id":"bc53a3aa971c1371","repo":"microsoft/aspire","slug":"failed-to-authenticate-to-the-apphost-server-bc53a3","errorCode":null,"errorMessage":"failed to authenticate to the AppHost server","messagePattern":"failed to authenticate to the AppHost server","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"src/Aspire.Hosting.CodeGeneration.Go/Resources/transport.go","lineNumber":709,"sourceCode":"\tcase []any:\n\t\tresult := make([]any, len(v))\n\t\tfor i, item := range v {\n\t\t\tresult[i] = c.marshalTransportValue(item)\n\t\t}\n\t\treturn result\n\tdefault:\n\t\treturn serialized\n\t}\n}\n\nfunc (c *client) authenticate(ctx context.Context, token string) error {\n\tresult, err := c.sendRequest(ctx, \"authenticate\", []any{token})\n\tif err != nil {\n\t\treturn err\n\t}\n\tauthenticated, _ := result.(bool)\n\tif !authenticated {\n\t\treturn errors.New(\"failed to authenticate to the AppHost server\")\n\t}\n\treturn nil\n}\n\nfunc (c *client) cancelToken(tokenID string) bool {\n\tresult, err := c.sendRequest(context.Background(), \"cancelToken\", []any{tokenID})\n\tif err != nil {\n\t\treturn false\n\t}\n\tb, _ := result.(bool)\n\treturn b\n}\n\nfunc (c *client) ping(ctx context.Context) (string, error) {\n\tresult, err := c.sendRequest(ctx, \"ping\", nil)\n\tif err != nil {\n\t\treturn \"\", err\n\t}","sourceCodeStart":691,"sourceCodeEnd":727,"githubUrl":"https://github.com/microsoft/aspire/blob/25830f84bd145686607ad00c057b3f84e2e51d43/src/Aspire.Hosting.CodeGeneration.Go/Resources/transport.go#L691-L727","documentation":"Returned by authenticate when the AppHost server responds to the \"authenticate\" JSON-RPC request with something other than true — typically false, meaning the supplied ASPIRE_REMOTE_APPHOST_TOKEN did not match the server's expected token. connect wraps it as \"failed to authenticate to AppHost\" and disconnects the client.","triggerScenarios":"CreateBuilder → connect → authenticate sends the env token; the server's result is false (token mismatch) or a non-bool (type-assertion `result.(bool)` fails, also yielding !authenticated). Fired on token mismatch between client environment and the running AppHost session.","commonSituations":"Stale ASPIRE_REMOTE_APPHOST_TOKEN from a previous AppHost run being reused against a new AppHost; token copied from another machine/session; a server error response shape (non-bool result) after a server-side exception; multiple AppHosts running with different tokens.","solutions":["Restart the app via `aspire run` so the current, correct ASPIRE_REMOTE_APPHOST_TOKEN is injected","Clear any stale exported token: unset ASPIRE_REMOTE_APPHOST_TOKEN and rerun under aspire run","Confirm only one AppHost session is running and the client connects to its matching socket path","Check AppHost server logs for why the authenticate call returned false or a non-bool result"],"exampleFix":null,"handlingStrategy":"validation","validationCode":"token := os.Getenv(\"ASPIRE_REMOTE_APPHOST_TOKEN\")\nif token == \"\" || token != currentSessionToken() {\n\treturn errors.New(\"token mismatch: restart via 'aspire run'\")\n}","typeGuard":null,"tryCatchPattern":"if err != nil && strings.Contains(err.Error(), \"failed to authenticate\") {\n\t// token mismatch: restart app under the current aspire run session\n}","preventionTips":["Use the token from the current AppHost session only","Run exactly one AppHost per client","Unset stale exported tokens before `aspire run`","Restart the client whenever the AppHost restarts"],"tags":["go","authentication","token","apphost","security"],"backgroundTag":"authentication-required","analyzedSha":"25830f84bd145686607ad00c057b3f84e2e51d43","analyzedAt":"2026-09-16T11:10:06.193Z","contentChangedAt":"2026-09-16T11:10:06.193Z","schemaVersion":2},"datasetVersion":"2026-09-21T04:17:39.646Z"}