[Proposition] Add nix flake for flow-cli installation and development

.gitignore

@@ -34,4 +34,9 @@ main
 imports
 
 # Goreleaser .env
-.release-env
+.release-env
+
+# Nix build artifacts
+result
+result-*
+.direnv/

CONTRIBUTING.md

@@ -36,6 +36,22 @@ To run the repo:
 go run cmd/flow/main.go
 ```
 
+### Getting Started with Nix
+
+If you use Nix with flakes enabled, you can just use:
+
+```bash
+# Enter development shell
+nix develop
+
+# Run the CLI
+go run cmd/flow/main.go
+
+# Or build and run
+nix build
+./result/bin/flow
+```
+
 ## How Can I Contribute?
 
 ### Reporting Bugs

flake.nix

@@ -0,0 +1,98 @@
+{
+  description = "Flow CLI - Command-line interface for the Flow blockchain";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs = { self, nixpkgs, flake-utils }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        pkgs = import nixpkgs { inherit system; };
+
+        # Version detection:
+        # - When building from a git tag (e.g., nix build github:onflow/flow-cli/v2.14.2),
+        #   the version is extracted from the tag.
+        # - For local development builds, version is "dev" (for nix metadata) and semver
+        #   is empty so build.go sets it to "undefined", matching Makefile behavior and
+        #   enabling isDevelopment() checks (skips version warnings and crash reporting).
+        isRelease = (self ? ref) && (builtins.match "v[0-9]+\..+" self.ref != null);
+        version =
+          if isRelease
+          then builtins.substring 1 (-1) self.ref  # Remove 'v' prefix for nix version
+          else "dev";
+        # semver is what gets injected into the Go binary via ldflags.
+        # Empty string → build.go init() sets it to "undefined" → isDevelopment() == true
+        semver =
+          if isRelease
+          then self.ref  # Full tag with 'v' prefix (e.g., "v2.14.2")
+          else "";
+
+        shortRev = self.shortRev or "dev";
+      in
+      {
+        packages = {
+          flow-cli = pkgs.buildGoModule {
+            pname = "flow-cli";
+            version = version;
+            src = ./.;
+
+            vendorHash = "sha256-EYQfXvHiRftod45Rvi7dUHF+3G5PyDtdM+HmJsE5r4I=";
+            proxyVendor = true;
+
+            subPackages = [ "cmd/flow" ];
+
+            env = {
+              CGO_ENABLED = "1";
+              CGO_CFLAGS = "-O2 -D__BLST_PORTABLE__";
+            };
+
+            ldflags = [
+              "-s" "-w"
+              "-X github.com/onflow/flow-cli/build.semver=${semver}"
+              "-X github.com/onflow/flow-cli/build.commit=${shortRev}"
+              "-X github.com/onflow/flow-cli/internal/accounts.accountToken=lilico:sF60s3wughJBmNh2"
+              "-X github.com/onflow/flow-cli/internal/command.MixpanelToken=3fae49de272be1ceb8cf34119f747073"
+            ];
+
+            preCheck = ''
+              export SKIP_NETWORK_TESTS=1
+            '';
+
+            meta = with pkgs.lib; {
+              description = "Command-line interface for the Flow blockchain";
+              homepage = "https://developers.flow.com/tools/flow-cli";
+              license = licenses.asl20;
+              mainProgram = "flow";
+            };
+          };
+
+          default = self.packages.${system}.flow-cli;
+        };
+
+        apps = {
+          flow-cli = flake-utils.lib.mkApp {
+            drv = self.packages.${system}.flow-cli;
+            name = "flow";
+          };
+          default = self.apps.${system}.flow-cli;
+        };
+
+        devShells.default = pkgs.mkShell {
+          buildInputs = with pkgs; [
+            go
+            golangci-lint
+            gotools
+            gopls
+            delve
+            gnumake
+            git
+          ];
+
+          CGO_ENABLED = 1;
+          CGO_CFLAGS = "-O2 -D__BLST_PORTABLE__";
+        };
+      }
+    );
+}