plandex-ai/plandex · error

Error encoding custom provider: %v

Error message

Error encoding custom provider: %v

What it means

GetCustomProviderHandler encodes res.ToApi() into the response with json.NewEncoder(w).Encode; on failure it logs 'Error encoding custom provider' and returns 500. The JSON encoding of a CustomProvider rarely fails on data; the usual cause is the HTTP connection failing while the encoder writes (client gone, connection reset).

Source

Thrown at app/server/handlers/models.go:424

func GetCustomProviderHandler(w http.ResponseWriter, r *http.Request) {
	auth := Authenticate(w, r, true)
	if auth == nil {
		return
	}

	id := mux.Vars(r)["providerId"]

	res, err := db.GetCustomProvider(auth.OrgId, id)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}

	err = json.NewEncoder(w).Encode(res.ToApi())
	if err != nil {
		log.Printf("Error encoding custom provider: %v\n", err)
		http.Error(w, fmt.Sprintf("Error encoding custom provider: %v", err), http.StatusInternalServerError)
		return
	}

	log.Println("Successfully fetched custom provider")
}

func ListCustomProvidersHandler(w http.ResponseWriter, r *http.Request) {
	auth := Authenticate(w, r, true)
	if auth == nil {
		return
	}

	if os.Getenv("IS_CLOUD") != "" {
		http.Error(w, "Custom model providers are not supported on Plandex Cloud", http.StatusBadRequest)
		return
	}

	list, err := db.ListCustomProviders(auth.OrgId)

View on GitHub (pinned to e2d772072e)

Solutions

1. Check whether the requesting client actually received anything; a disconnect here is benign — retry the request.
2. Review proxy/load-balancer timeout configuration for premature connection closes.
3. If reproducible with healthy connections, inspect CustomProvider.ToApi() for newly added unmarshalable fields.
4. Marshal to a buffer before writing so encode errors are separated from transport write errors.

Example fix

// before
err = json.NewEncoder(w).Encode(res.ToApi())
if err != nil {
    http.Error(w, fmt.Sprintf("Error encoding custom provider: %v", err), http.StatusInternalServerError)
}
// after
buf, err := json.Marshal(res.ToApi())
if err != nil {
    http.Error(w, "encoding failed", http.StatusInternalServerError)
    return
}
w.Header().Set("Content-Type", "application/json")
w.Write(buf)

// Caller: ensure a live connection and a non-cancelled context before requesting
if r.Context().Err() != nil { return }
req, _ := http.NewRequestWithContext(r.Context(), "GET", providerURL, nil)

if err := json.NewEncoder(w).Encode(res.ToApi()); err != nil {
    log.Printf("Error encoding custom provider: %v", err)
    return // headers may already be sent; do not attempt http.Error after a partial write
}

When it happens

Trigger: GET custom provider where the client disconnects or the transport errors while the JSON body is written to the ResponseWriter.

Common situations: Client aborts the request right after it is issued; proxy timeout kills the upstream connection during the write; network drop on mobile clients.

Related errors

• Error encoding custom model: %v
• Error encoding custom models: %v
• token exchange failed - error reading body: %s
• failed to update context: %v
• failed to download the update: %w

AI-assisted analysis of plandex-ai/plandex@e2d772072e (2026-09-05). Data as JSON: /api/errors/eda091a47391e64e. Report an issue: GitHub.