diff --git a/CHANGELOG.md b/CHANGELOG.md
index 342836a72..337220261 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -50,6 +50,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - **Audit operation labels**: added human-readable descriptions for the new `SKILL_*`, `MCP_*`, and `SECRET_*` operation types, and a `humanize()` fallback so any future operation type renders as "Something New" instead of "Performed unknown operation"
 
 ### Fixed
+- **GitHub repo name conflict returns 409 instead of 500**: creating a project on GitHub with a repo name that already exists on the linked account previously surfaced as an opaque "Internal Server Error". The GitHub provider now detects the `422 name already exists` response and raises a typed `GitProviderError::RepositoryAlreadyExists { name }`, which the handler maps to **409 Conflict** with an actionable detail message. The frontend `extractProblemDetails` helper was also fixed to (1) use the correct RFC 7807 field name `type` (previously `type_url`), (2) unwrap `body` / `error` / `data` envelopes used by the hey-api openapi-ts client, and (3) gate detection on a proper type guard so unrelated thrown objects are no longer misidentified as ProblemDetails. Users now see a clear "Repository Already Exists" toast and can pick a different name without contacting support.
 - **`/projects/new` browser navigation**: the source picker (Import / Template / Git URL / Manual) now mirrors the chosen mode to a `?source=` query param, plus the chosen template (`&template=<slug>`) or validated public Git URL (`&repo=<url>`). Browser back/forward, deep links, and tab restore all work — reloading on `?source=templates&template=nextjs-saas-starter` lands directly in the template configurator, and `?source=git-url&repo=https%3A%2F%2F...` re-validates the URL on mount. Sub-keys are cleared automatically when the source changes so we never end up with stale state like `?source=git-url&template=foo`. The inline mode (used inside the onboarding flow) continues to use plain React state since it doesn't own the URL.
 - **`app_url` generator inherits port from external_url when preview_domain is set**: a dev install with `preview_domain=*.localho.st` + `external_url=http://localhost:8080` previously produced `https://my-app.localho.st` (missing port, wrong scheme) because `preview_domain` won the priority and didn't carry transport details. Now when both settings are present, scheme and port are inherited from `external_url` while the host comes from `preview_domain` — yielding `http://my-app.localho.st:8080`.
 - **Per-provider icons in Git connection pickers**: GitHub, GitLab, and other connections now render the correct icon in both the `/projects/new` source picker and the Template configurator's Git Provider field, instead of always showing the GitHub mark. Resolved by joining `ConnectionResponse.provider_id` against the cached providers list.
diff --git a/crates/temps-git/src/handlers/base.rs b/crates/temps-git/src/handlers/base.rs
index d929d52d0..8d7bb11a6 100644
--- a/crates/temps-git/src/handlers/base.rs
+++ b/crates/temps-git/src/handlers/base.rs
@@ -52,9 +52,7 @@ impl From<GitProviderManagerError> for Problem {
                     .with_title("Database Error")
                     .with_detail(e.to_string())
             }
-            GitProviderManagerError::ProviderError(e) => problem_new(StatusCode::BAD_REQUEST)
-                .with_title("Provider Error")
-                .with_detail(e.to_string()),
+            GitProviderManagerError::ProviderError(e) => Problem::from(e),
             GitProviderManagerError::ProviderNotFound(msg) => problem_new(StatusCode::NOT_FOUND)
                 .with_title("Provider Not Found")
                 .with_detail(msg),
@@ -130,6 +128,15 @@ impl From<GitProviderError> for Problem {
                 .with_type("https://docs.temps.sh/errors/api_error")
                 .with_title("API Error")
                 .with_detail(msg),
+            GitProviderError::RepositoryAlreadyExists { ref name } => {
+                problem_new(StatusCode::CONFLICT)
+                    .with_type("https://docs.temps.sh/errors/repository_already_exists")
+                    .with_title("Repository Already Exists")
+                    .with_detail(format!(
+                        "A repository named '{}' already exists in the target account. Choose a different name.",
+                        name
+                    ))
+            }
             GitProviderError::NotImplemented => problem_new(StatusCode::NOT_IMPLEMENTED)
                 .with_type("https://docs.temps.sh/errors/not_implemented")
                 .with_title("Not Implemented")
diff --git a/crates/temps-git/src/services/git_provider.rs b/crates/temps-git/src/services/git_provider.rs
index 7cead2ddc..a3a7de435 100644
--- a/crates/temps-git/src/services/git_provider.rs
+++ b/crates/temps-git/src/services/git_provider.rs
@@ -23,6 +23,9 @@ pub enum GitProviderError {
     #[error("API error: {0}")]
     ApiError(String),
 
+    #[error("A repository named '{name}' already exists on this account")]
+    RepositoryAlreadyExists { name: String },
+
     #[error("Not implemented for this provider")]
     NotImplemented,
 
diff --git a/crates/temps-git/src/services/github_provider.rs b/crates/temps-git/src/services/github_provider.rs
index 79f3be3ad..bd9a5409c 100644
--- a/crates/temps-git/src/services/github_provider.rs
+++ b/crates/temps-git/src/services/github_provider.rs
@@ -1457,6 +1457,35 @@ impl GitProviderService for GitHubProvider {
                 .await
                 .unwrap_or_else(|_| "Unknown error".to_string());
             error!("Failed to create repository: {} - {}", status, error_text);
+
+            // Detect GitHub's "name already exists" 422 and surface as a typed
+            // variant so handlers can return 409 Conflict with a clean message.
+            if status.as_u16() == 422 {
+                #[derive(Deserialize)]
+                struct GhFieldError {
+                    field: Option<String>,
+                    message: Option<String>,
+                }
+                #[derive(Deserialize)]
+                struct GhErrorBody {
+                    errors: Option<Vec<GhFieldError>>,
+                }
+                if let Ok(body) = serde_json::from_str::<GhErrorBody>(&error_text) {
+                    let name_taken = body.errors.iter().flatten().any(|e| {
+                        e.field.as_deref() == Some("name")
+                            && e.message
+                                .as_deref()
+                                .map(|m| m.contains("already exists"))
+                                .unwrap_or(false)
+                    });
+                    if name_taken {
+                        return Err(GitProviderError::RepositoryAlreadyExists {
+                            name: name.to_string(),
+                        });
+                    }
+                }
+            }
+
             return Err(GitProviderError::ApiError(format!(
                 "Failed to create repository: {} - {}",
                 status, error_text
diff --git a/crates/temps-projects/src/handlers/handlers.rs b/crates/temps-projects/src/handlers/handlers.rs
index 205949c9b..98995ae2f 100644
--- a/crates/temps-projects/src/handlers/handlers.rs
+++ b/crates/temps-projects/src/handlers/handlers.rs
@@ -1245,12 +1245,9 @@ pub async fn create_project_from_template(
         .await
         .map_err(|e| {
             error!("Failed to create repository from template: {:?}", e);
-            problemdetails::new(http::StatusCode::INTERNAL_SERVER_ERROR)
-                .with_title("Repository Creation Failed")
-                .with_detail(format!(
-                    "Failed to create repository and push template code: {}",
-                    e
-                ))
+            // Forward the typed Problem (e.g. 409 for "name already exists",
+            // 401 for auth failures) instead of flattening everything to 500.
+            Problem::from(e)
         })?;
 
     info!(
diff --git a/web/src/utils/errorHandling.ts b/web/src/utils/errorHandling.ts
index e462953c1..9049f863e 100644
--- a/web/src/utils/errorHandling.ts
+++ b/web/src/utils/errorHandling.ts
@@ -48,21 +48,38 @@ export function getExpiredTokenMessage(
 }
 
 /**
- * Extract ProblemDetails from an error
+ * Extract ProblemDetails from an error.
+ *
+ * The hey-api openapi-ts client (with `throwOnError: true`) throws the parsed
+ * response body directly, so `error` is typically the `ProblemDetails` object
+ * itself. Older fetch-style errors may nest it under `body`. RFC 7807 uses
+ * `type` (not `type_url`), so we identify a ProblemDetails by the presence
+ * of a `title` string plus at least one of the canonical fields.
  */
 export function extractProblemDetails(error: unknown): ProblemDetails | null {
   if (!error || typeof error !== 'object') return null
 
-  const err = error as any
+  const looksLikeProblem = (val: unknown): val is ProblemDetails => {
+    if (!val || typeof val !== 'object') return false
+    const v = val as Record<string, unknown>
+    return (
+      typeof v.title === 'string' &&
+      ('detail' in v || 'type' in v || 'status' in v || 'extensions' in v)
+    )
+  }
+
+  const err = error as Record<string, unknown>
 
-  // Check if error has a body property (from fetch API)
-  if (err.body && typeof err.body === 'object') {
-    return err.body as ProblemDetails
+  // Some clients nest the parsed body under `body`, `error`, or `data`.
+  for (const key of ['body', 'error', 'data'] as const) {
+    if (looksLikeProblem(err[key])) {
+      return err[key] as ProblemDetails
+    }
   }
 
-  // Check if error itself is ProblemDetails
-  if ('title' in err && 'type_url' in err) {
-    return err as ProblemDetails
+  // Default case: the thrown value IS the ProblemDetails.
+  if (looksLikeProblem(err)) {
+    return err
   }
 
   return null