atlan-python: Instructions file for Codex

Security

Follow these security guidelines for every change to the pyatlan SDK.

Contact

• Security Team: #bu-security-and-it on Slack

Quickstart for Agents

atlan-python (pyatlan) is Atlan's Python SDK, providing typed wrappers around the Atlan REST API. Key modules:

• pyatlan/client/atlan.py — AtlanClient (Pydantic BaseSettings); initialised with base_url and api_key; uses httpx with PyatlanSyncTransport / async variant; supports impersonation via ImpersonationClient.
• pyatlan/client/transport.py — PyatlanSyncTransport and async variant wrap httpx.HTTPTransport with retry logic; trust_env=True by default to respect HTTPS_PROXY env.
• pyatlan/client/credential.py — manages credential objects (Vault-stored secrets).
• pyatlan/client/token.py — manages API tokens (long-lived service account keys).
• pyatlan/cache/ — caches for tags, groups, roles, custom metadata.

Review every change for:

• API key logging — AtlanClient holds api_key (set as Authorization: Bearer <key> on every request); it must never appear in log output, error messages, or exception tracebacks; wrap all httpx error handling to strip Authorization from logged request details; the api_key field must be excluded from any Pydantic model dict() / model_dump() used for logging.
• Impersonation token safety — ImpersonationClient generates short-lived impersonation JWTs; these tokens must not be logged; the target user's identity (email/username) may be logged but not the token value.
• TLS verification — PyatlanSyncTransport must never pass verify=False to httpx.HTTPTransport; if users need to use custom CA bundles, accept a path to the bundle, not a False flag.
• base_url validation — base_url is validated as HttpUrl via Pydantic; ensure validation rejects non-HTTPS URLs in production builds (the HttpUrl type allows HTTP by default — add a validator if HTTPS is required).
• Proxy credential exposure — trust_env=True means HTTPS_PROXY is honoured; proxy credentials embedded in the URL (e.g., http://user:pass@proxy) must not be echoed in log output; strip credentials from proxy URLs before logging.
• Credential object sensitivity — CredentialClient returns objects with username and potentially password fields; these must not be logged; use repr/str exclusion for credential model classes.