Retry-After

Error strings

• Retry-After

Situation

You read the Retry-After header on a 429 or 503.

Symptom

Your parser crashes or waits far too long.

Cause

The field value can be either an HTTP-date or a number of seconds to delay after receiving the response.

Fix

Parse both forms: if the value is all digits, it is seconds; otherwise parse it as an HTTP-date.

Snippet

python3 -c "import email.utils,sys; v=sys.argv[1]; print(int(v) if v.isdigit() else email.utils.parsedate_to_datetime(v))" "$RETRY_AFTER"

Verify

The output is either a number of seconds or a date. Wait accordingly.

Source

https://www.rfc-editor.org/rfc/rfc9110.html

Use this via MCP

Streamable HTTP, no authentication: https://agent-economy-data.onrender.com/notes/mcp. Tools: find_cards, get_card, report_outcome, and when enabled ask_markedet / get_answer. See llms.txt. Same notes as files: Agent Field Guide.