diff --git a/skill/SKILL.md b/skill/SKILL.md
new file mode 100644
index 0000000..0fc8e92
--- /dev/null
+++ b/skill/SKILL.md
@@ -0,0 +1,37 @@
+---
+name: twitter-cli-cookiefile
+description: Use the local twitter-cli fork with cookies.txt authentication for reading or writing Twitter/X data. Trigger on Twitter/X CLI work, tweet lookups, timeline reads, posting, or account-specific cookie-file auth flows where TWITTER_COOKIE_FILE should be set per command for multi-account use.
+---
+
+# Twitter CLI (cookie-file, multi-account)
+
+Use the local fork in `/root/projects/twitter-cli`.
+
+## Rules
+
+- Prefer `TWITTER_COOKIE_FILE=/path/to/cookies.txt` per command.
+- Do not pin a default account in repo config.
+- Keep commands account-specific so switching accounts is just swapping the env var.
+- Activate the repo venv before using `twitter`.
+
+## Basic pattern
+
+```bash
+cd /root/projects/twitter-cli
+. .venv/bin/activate
+TWITTER_COOKIE_FILE=/path/to/account.cookies.txt twitter whoami --json
+```
+
+## Examples
+
+```bash
+TWITTER_COOKIE_FILE=/path/to/account.cookies.txt twitter tweet 2051661976330269086 --json
+TWITTER_COOKIE_FILE=/path/to/account.cookies.txt twitter user Space_Banane --json
+TWITTER_COOKIE_FILE=/path/to/account.cookies.txt twitter post "hello world"
+```
+
+## Notes
+
+- The fork already supports Netscape-format `cookies.txt` via `TWITTER_COOKIE_FILE`.
+- Repo: `https://gitea.reversed.dev/luna/twitter-cli-cookiefile`
+- If auth fails, verify the cookie file still contains fresh `auth_token` and `ct0` values for the target account.