diff --git a/src/features/opencode-skill-loader/git-master-template-injection.test.ts b/src/features/opencode-skill-loader/git-master-template-injection.test.ts
index 06be6051e..a521e13f4 100644
--- a/src/features/opencode-skill-loader/git-master-template-injection.test.ts
+++ b/src/features/opencode-skill-loader/git-master-template-injection.test.ts
@@ -231,6 +231,18 @@ describe("#given buildShellAwareGitPrefix", () => {
 		})
 	})
 
+	describe("#when shell type is csh", () => {
+		it("#then returns csh setenv syntax", () => {
+			const result = buildShellAwareGitPrefix("GIT_MASTER=1", "csh")
+			expect(result).toBe("setenv GIT_MASTER 1;")
+		})
+
+		it("#then handles multiple env vars", () => {
+			const result = buildShellAwareGitPrefix("CI=true GIT_MASTER=1", "csh")
+			expect(result).toBe("setenv CI true; setenv GIT_MASTER 1;")
+		})
+	})
+
 	describe("#when prefix is empty", () => {
 		it("#then returns empty string", () => {
 			const result = buildShellAwareGitPrefix("", "powershell")
@@ -319,4 +331,61 @@ describe("#given PowerShell shell detection in injectGitMasterConfig", () => {
 			expect(result).not.toContain("$env:")
 		})
 	})
+
+	describe("#when shell is csh (SHELL set to /bin/csh)", () => {
+		it("#then emits setenv prefix syntax in csh code block", () => {
+			process.env.SHELL = "/bin/csh"
+			delete process.env.PSModulePath
+			delete process.env.MSYSTEM
+			Object.defineProperty(process, "platform", { value: "linux" })
+
+			const result = injectGitMasterConfig(SAMPLE_TEMPLATE, {
+				commit_footer: false,
+				include_co_authored_by: false,
+				git_env_prefix: "GIT_MASTER=1",
+			})
+
+			expect(result).toContain("setenv GIT_MASTER 1;")
+			expect(result).toContain("```csh")
+			expect(result).not.toContain("```bash\nsetenv")
+		})
+
+		it("#then does NOT prefix bash code blocks with setenv syntax", () => {
+			process.env.SHELL = "/bin/csh"
+			delete process.env.PSModulePath
+			delete process.env.MSYSTEM
+			Object.defineProperty(process, "platform", { value: "linux" })
+
+			const result = injectGitMasterConfig(SAMPLE_TEMPLATE, {
+				commit_footer: false,
+				include_co_authored_by: false,
+				git_env_prefix: "GIT_MASTER=1",
+			})
+
+			const bashBlockMatch = result.match(/```bash\r?\n([\s\S]*?)```/g)
+			if (bashBlockMatch) {
+				for (const block of bashBlockMatch) {
+					expect(block).not.toContain("setenv")
+				}
+			}
+		})
+	})
+
+	describe("#when shell is tcsh (SHELL set to /usr/local/bin/tcsh)", () => {
+		it("#then emits setenv prefix syntax in csh code block", () => {
+			process.env.SHELL = "/usr/local/bin/tcsh"
+			delete process.env.PSModulePath
+			delete process.env.MSYSTEM
+			Object.defineProperty(process, "platform", { value: "darwin" })
+
+			const result = injectGitMasterConfig(SAMPLE_TEMPLATE, {
+				commit_footer: false,
+				include_co_authored_by: false,
+				git_env_prefix: "GIT_MASTER=1",
+			})
+
+			expect(result).toContain("setenv GIT_MASTER 1;")
+			expect(result).toContain("```csh")
+		})
+	})
 })
diff --git a/src/features/opencode-skill-loader/git-master-template-injection.ts b/src/features/opencode-skill-loader/git-master-template-injection.ts
index 0483c2fc0..e1b1b05ba 100644
--- a/src/features/opencode-skill-loader/git-master-template-injection.ts
+++ b/src/features/opencode-skill-loader/git-master-template-injection.ts
@@ -26,15 +26,17 @@ export function parseBashEnvPrefix(prefix: string): Record<string, string> {
 /**
  * Build the shell-aware command prefix for git commands.
  * Uses the shared shell detection and env prefix builder to emit correct syntax
- * for PowerShell ($env:VAR='value';), cmd (set VAR="value" &&), or unix (VAR=value).
+ * for PowerShell ($env:VAR='value';), cmd (set VAR="value" &&),
+ * csh (setenv VAR value;), or unix (VAR=value).
  *
  * For unix shells, we use the inline VAR=value prefix style (not export) to match
  * the original behavior where the env var applies only to the immediately following command.
+ * For csh/tcsh, we use setenv syntax since csh does not support inline VAR=value.
  */
 export function buildShellAwareGitPrefix(bashPrefix: string, shellType?: ShellType): string {
 	if (!bashPrefix) return ""
 	const resolvedShellType = shellType ?? detectShellType()
-	if (resolvedShellType === "unix" || resolvedShellType === "csh") {
+	if (resolvedShellType === "unix") {
 		return bashPrefix
 	}
 	const envRecord = parseBashEnvPrefix(bashPrefix)
@@ -48,8 +50,8 @@ export function injectGitMasterConfig(template: string, config?: GitMasterConfig
 
 	const shellType = detectShellType()
 	const shellPrefix = gitEnvPrefix ? buildShellAwareGitPrefix(gitEnvPrefix, shellType) : ""
-	const codeBlockLang = shellType === "powershell" ? "pwsh" : "bash"
-	const skipBashBlockPrefixing = shellType === "powershell" || shellType === "cmd"
+	const codeBlockLang = shellType === "powershell" ? "pwsh" : shellType === "csh" ? "csh" : "bash"
+	const skipBashBlockPrefixing = shellType === "powershell" || shellType === "cmd" || shellType === "csh"
 
 	let result = gitEnvPrefix ? injectGitEnvPrefix(template, shellPrefix, codeBlockLang) : template