derivation-stateful-logic SKILL.md skillA
derivation-stateful-logic from estuary/agent-skills is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add estuary/agent-skills/derivation-stateful-logic@git:20260707.6b608bfPins git:20260707.6b608bf in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- estuary/agent-skills
- Path
skills/derivation-stateful-logic/SKILL.md- Versions recorded
- 1
- Latest version
- git:20260707.6b608bf, committed Jul 7, 2026
- Size
- 13,208 bytes
- Repository stars
- 7
- License
- Apache-2.0
Create an Estuary derivation with custom SQLite state (internal tables) to make per-document decisions based on accumulated history — account balances, inventory levels, approval workflows, deduplication. Derivations add complexity and cost — confirm the user wants a derivation before reaching for this. Use when user says "stateful derivation", "derivation to track balance", "transformation to approve based on state", "derive an approval workflow", "deduplication derivation", or…
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# derivation-stateful-logic Estuary derivation that maintains internal SQLite tables to record state, and whose lambdas query and update that state to decide what to emit. **Prereq:** read `derivation-basics` first — in particular the stateless-vs-stateful distinction and the role of migrations. This skill is the "stateful via SQLite tables" path. **Docs:** - https://docs.estuary.dev/getting-started/tutorials/derivations_acmebank/ — the canonical stateful tutorial (deposits, withdrawals, transfer approval) with the exact pattern this skill uses - https://docs.estuary.dev/concepts/derivations/#internal-state — the concept page on internal task state ## When to use this over alternatives - **Balance / account state**: debit sender if funds available, reject otherwise - **Inventory**: deduct stock, mark backordered if insufficient - **Approval workflows**: accumulate approvers, emit "approved" once threshold met - **Deduplication with history**: filter events by ID seen-before (beyond what collection-key uniqueness gives) - **Any business logic that depends on prior events for the same key** Reach for other skills when: …
Read the whole file at its exact version.
How to install
mdr add estuary/agent-skills/derivation-stateful-logic@sha256:ea92bd873a80b43aThe line at the top of this page pins the label git:20260707.6b608bf, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_4rgf43lky7mdilil)
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Versions
The registry has recorded 1 version of this file, committed on Jul 7, 2026.
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (13208 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
estuary/agent-skills · 7 stars · license Apache-2.0 · pushed 2026-11-04 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_4rgf43lky7mdilil GET https://markdownregistry.com/api/v1/resolve?ref=estuary/agent-skills/derivation-stateful-logic GET https://markdownregistry.com/api/v1/blob/ea92bd873a80b43a760c512fd7a170c7e363ddf1cc95edf63e8e376201f2147e
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.