diff --git a/.github/ISSUE_TEMPLATE/bug_report.md b/.github/ISSUE_TEMPLATE/bug_report.md
new file mode 100644
index 0000000..f03978c
--- /dev/null
+++ b/.github/ISSUE_TEMPLATE/bug_report.md
@@ -0,0 +1,22 @@
+---
+name: Bug report
+about: Something is broken
+labels: bug
+---
+
+**Command** (redact your token):
+
+```sh
+afcli ...
+```
+
+**Expected behavior**
+
+**Actual behavior / error output**
+
+```
+```
+
+**Environment**
+- afcli version (`afcli --version`):
+- OS:
diff --git a/.github/ISSUE_TEMPLATE/feature_request.md b/.github/ISSUE_TEMPLATE/feature_request.md
new file mode 100644
index 0000000..68c1b02
--- /dev/null
+++ b/.github/ISSUE_TEMPLATE/feature_request.md
@@ -0,0 +1,11 @@
+---
+name: Feature request
+about: Suggest a new command, flag, or API to support
+labels: enhancement
+---
+
+**What would you like afcli to do?**
+
+**Which AppsFlyer API does this relate to?** (link to the docs page if possible)
+
+**How would you use it?** (example command line)
diff --git a/.github/pull_request_template.md b/.github/pull_request_template.md
new file mode 100644
index 0000000..c951e9e
--- /dev/null
+++ b/.github/pull_request_template.md
@@ -0,0 +1,11 @@
+## What does this PR do?
+
+## Related issue
+
+<!-- Closes #... or "none" -->
+
+## Checklist
+
+- [ ] `go test ./...` passes
+- [ ] `gofmt` / `go vet` are clean
+- [ ] Docs (README / --help text) updated if behavior changed
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index e2c36de..169eb01 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -9,7 +9,7 @@ jobs:
   test:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v7
       - uses: actions/setup-go@v5
         with:
           go-version-file: go.mod
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index b0ec03a..1648be3 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -11,7 +11,7 @@ jobs:
   goreleaser:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v7
         with:
           fetch-depth: 0
       - uses: actions/setup-go@v5
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
new file mode 100644
index 0000000..5d3826d
--- /dev/null
+++ b/CONTRIBUTING.md
@@ -0,0 +1,32 @@
+# Contributing
+
+Thanks for your interest in improving afcli!
+
+## Development setup
+
+Go 1.26 or later is required.
+
+```sh
+git clone https://github.com/rie03p/appsflyer-cli.git
+cd appsflyer-cli
+go build -o afcli ./cmd/afcli
+go test ./...
+```
+
+## Project layout
+
+- `cmd/afcli` — entry point.
+- `internal/appsflyer` — API client, one file per API family (raw data, aggregate, master, ...). No CLI dependencies.
+- `internal/cli` — the cobra command tree, one file per command.
+
+To add support for a new AppsFlyer API, add a client file in `internal/appsflyer` with a params struct and a `Client` method, then a matching command file in `internal/cli`. Both layers are tested against `httptest` servers — see the existing `_test.go` files for the pattern.
+
+## Pull requests
+
+- Keep each PR focused on one change.
+- Run `gofmt`, `go vet ./...`, and `go test ./...` before pushing (CI enforces all three).
+- Use [Conventional Commits](https://www.conventionalcommits.org/) for commit messages (`feat:`, `fix:`, `docs:`, ...) — release notes are generated from them.
+
+## Reporting issues
+
+Bug reports and feature requests are welcome via [GitHub issues](https://github.com/rie03p/appsflyer-cli/issues). For bugs, include the command you ran (with the token redacted) and the error output.