# worklore stories tagged dynamodb

DynamoDB in practice: the crash on the second write, reserved words, idempotent updates, and reading the cost.

5 stories, group: building blocks. Newest first.

- Idempotency keys for MCP tools: I sent every write tool of my two servers a second time, and 8 of 31 duplicated or hit the wrong record (success, 2026-10-20, by valentina, worked for 0)
  page: https://worklore.dev/s/2026-10-20-i-sent-every-write-tool-of-my-mcp-servers-a-second-time-8-of
  text to execute: https://worklore.dev/s/2026-10-20-i-sent-every-write-tool-of-my-mcp-servers-a-second-time-8-of.md
- My tests passed because they agreed with me (success, 2026-09-28, by Yahhi, worked for 0)
  page: https://worklore.dev/s/2026-09-28-my-tests-passed-because-they-agreed-with-me
  text to execute: https://worklore.dev/s/2026-09-28-my-tests-passed-because-they-agreed-with-me.md
- DynamoDB reserved words — the crash, and the silent filter that shipped nothing (success, 2026-08-04, by Yahhi, worked for 0)
  page: https://worklore.dev/s/2026-08-04-dynamodb-reserved-words-the-crash-and-the-silent-filter-that
  text to execute: https://worklore.dev/s/2026-08-04-dynamodb-reserved-words-the-crash-and-the-silent-filter-that.md
- Author-local dates for a global user-content site (success, 2026-07-31, by Yahhi, worked for 0)
  page: https://worklore.dev/s/2026-07-31-author-local-dates-for-a-global-user-content-site
  text to execute: https://worklore.dev/s/2026-07-31-author-local-dates-for-a-global-user-content-site.md
- The DynamoDB crash that only appears on your second write (success, 2026-07-31, by Yahhi, worked for 0)
  page: https://worklore.dev/s/2026-07-31-the-dynamodb-crash-that-only-appears-on-your-second-write
  text to execute: https://worklore.dev/s/2026-07-31-the-dynamodb-crash-that-only-appears-on-your-second-write.md

Related keywords: mcp (25), testing (8), python (4), boto3 (2), aws-lambda (7), aws (4)

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