FileMaker Developer AI Coding Skill
Updated: 6 days ago
The Latin root of 'hallucinate' is alucinari : to wander in the mind. That's a generous framing for what AI Agents actually do when they get it wrong.
This is part four in my Agentic Development series. Here's the link if you've not reviewed the previous post on FileMaker Agentic Development.
Example: Yesterday, I asked Claude to write a script that sets a variable from field data. It came back with a calculation built around a function GetContents ( fieldName ).
That function does not exist in FileMaker. When I pushed back, the Agent explained that GetContents had been deprecated in FileMaker 19. Also untrue. It never existed. The Agent fabricated a function, then fabricated a history for it.
That's not wandering. That's lying with confidence.
Why AI Hallucinates FileMaker Functions
Models have training cutoffs. Claris ships new functions, new Script Steps, and new behaviours with every release. By the time a model is trained and deployed, its FileMaker knowledge is already drifting.
It's not malicious. It's structural. And it costs you time every single day you use AI for FileMaker Development.
Every hallucinated function means debugging AI output instead of building. You paste something into the Specify Calculation dialog or Script Step, hit an error, and end up at the Claris Help Centre anyway. Where you should have started.
As part of the AI-Readiness of the Platform - Claris has published the Help Documentation in a LLM friendly combination of txt and .md files.
The Claris Help Centre at help.claris.com is comprehensive, versioned, and accurate. The problem is that Claude isn't referencing it. Until now.
The claris-filemaker-pro Skill for Claude Desktop
This 'claris-filemaker-pro' skill is my initial release to reduce this situation.
Skill.
A structured set of reference files and instructions that tells Claude which catalogs to check locally before fetching the live documents - before responding.
This reduces hallucination in FileMaker development contexts.
How to Install the claris-filemaker-pro Skill
The skill now installs as a plugin from the CadenceUX marketplace. Add the marketplace once and each update arrives without another download.
Claude Code. Run these two commands in the terminal:
claude plugin marketplace add https://github.com/CadenceUX/cadenceux-skills.gitclaude plugin install claris-filemaker-pro@cadenceuxClaude Desktop, claude.ai and Cowork. Open 'Customize', then 'Plugins', add a marketplace from GitHub, enter CadenceUX/cadenceux-skills, then install claris-filemaker-pro.
Manual. Download claris-filemaker-pro.skill and double-click it, or upload claris-filemaker-pro.zip via 'Customize' in Claude Desktop. Both links always fetch the latest release.
Example: Once you have the Skill installed, ask Claude to make you a stunning 'FileMaker Function Explorer' or 'FileMaker Skill Explorer'.
This Skill Lives on GitHub, Not Just a Blog Post
It's worth considering that building a Skill like this is itself an 'agile' project. Too many issues and updates for a static publishing method such as this blog.
This is why the skill lives in the GitHub repo CadenceUX claris-filemaker-pro-skill
Every change is in its changelog, against a version number. The rest of my FileMaker skills sit alongside it in the cadenceux-skills marketplace.
How the claris-filemaker-pro Skill Works
Ask your Agent to build a script or about a certain function or script step - via a number of 'Mandatory triggers' and terms built into the Skill ~ "How does 'While' work?" or "Write me a Let() calculation that . . ."
The Skill has the following workflow:
Work through the answer checklist in the skill, then open the reference file for the topic
Look up the exact format, return type and version in the function or Script Step catalog
Fetch the live Claris Help page when the topic is AI, newer than the catalog, or you ask for the 'latest'
Answer with the format inline, and cite the Claris Help page
As an example, ask "what local data in the skill do you have for GetPersistentData" and the Agent will return the following data:
Name: GetPersistentData
Format: GetPersistentData ( name ; instanceID )
Parameters: name, instanceID
Purpose: Returns a value from the persistent data store by name and instance ID;
store survives session end and file close
Category: Persistent data functions
Category URL: persistent-data-functions.html
Slug: getpersistentdata
Introduced in: FileMaker 26.0
Along with the gotchas that matter:
GetPersistentData ( "AppVersion" ; "" )
// → 2.1.0
No match returns '?'. It does not return empty. Use the real instance ID from ListPersistentDataIDs. An invented one returns '?'.
Writing needs Full Access. The Configure Persistent Data Script Step needs Full Access, or a script granted it. Reading doesn't.
It's schema, not data. Entries travel with a clone, but the Data Migration Tool does not copy them. Re-create them after a migration.
This is the detail that used to need a trip to the Help Centre. It's now local, and checked against the Claris page.
What the claris-filemaker-pro Skill Contains
The skill covers all 368 current calculation functions across 20 categories, and all 216 Script Steps across 16 categories. That includes the AI category: Configure AI Account, Generate Response from Model, Insert Embedding and Perform Semantic Find, among others.
Not guesswork. A proper catalog.
Eighteen reference files in total:
Two catalogs. Every function and Script Step with its format, version introduced, return type, platform support and Claris Help link
Eight example files. Logical, JSON, AI, Let(), Get(), design, container, text, date-time, numeric and specialty functions
Eight focused references. Error codes, Data API, OData, SQL, WebDirect, FileMaker Go, field types and a Help site map
Note: This is a 'reference' Skill. Scripts, Calculations and Error Codes only.
Custom Functions, Tables, Fields and Layouts, and other elements are excluded by design.
How the claris-filemaker-pro Skill Was Built
Early iterations had incorrect function and function details and counts.
The While() function reported 'originated in version' as 14 when it's clearly 18. Closer checking found an other 28+ incorrect versions of origin.
Each rebuild surfaced another gap. The AI functions category was the hardest. It's the newest, least stable, and the area where Claude's training data is most likely to be wrong. The version history tells the story.
The release version went from v0.1, a basic function index, through nine intermediate versions before calling it v1.0, and on through to the current v2.1.0.
v2.1.0 went a step further. Every example that can run without a record was run through the actual FileMaker calculation engine: 255 checked, 0 failing. That found errors no amount of reading would have, so I'm sharing them here for the community.
Example: The skill said JSONRaw returned 7. The engine says 0. A community member raised it as an issue on GitHub, which is exactly what the repo is there for.
The engine also caught that an HMAC comparison needs Exact(), because '=' ignores case. It caught that Base64Encode appends a carriage return and line feed, and that FileMaker sorts JSON object keys. Plausible, fluent, and wrong in the old examples. Now verified.
I also tested the skill the way the Knowledge Delegation post describes, asking Claude the same questions with the skill and without it. Without it, two of eight answers were correct. With it, Haiku, Sonnet and Opus all scored ten from ten.
FileMaker 26: It's Here
The skill was initially built and released against FileMaker 22.
FileMaker 26 has now been released with new features and functions, new Script Steps, and of course new AI capabilities. As mentioned earlier, there is also an AI-friendly version of the Claris Documentation.
The skill is current to FileMaker 26.0.3, the latest public release for Pro, Server, Go and Cloud. That includes the 26.0.3 change that makes Open PDF, Append PDF and Close PDF fully supported in WebDirect.
Version drift detection is still built in, just simpler. The skill checks GitHub once per session and tells you when a newer version is out. If a Claris page documents something newer than the catalog, the skill says its files may lag and answers from the page. The skill knows it will age, and it tells you when it has.
The rebuild process is documented. When FileMaker 'Next' ships, the catalogs are re-checked against Claris, the examples are re-run through the engine, and the version counter ticks over. Maintenance, not crisis management.
The skill is released under CC BY 4.0. Use it, fork it, adapt it. Attribute it. If you build something useful on top of it, I'd love to know.
Claris Agentic Development Toolkit (ADT)
Summer arrived. Winter, for those of us Down Under.
Claris has released the Agentic Development Toolkit (ADT) as a developer preview, with a wider rollout to Developers in the coming weeks. It installs its own Claude plugin, with Claris's own Help, coding standards and a command-line tool that runs the actual FileMaker calculation engine.
That changes the role of this skill, but it doesn't replace it. claris-filemaker-pro now has an ADT mode. When ADT is installed, the skill uses Claris's Help and validates calculations against the engine before answering. Without ADT, it works as before from its own catalogs. One skill, two modes. You don't need to choose.
The goal stays the same. Stop Claude guessing. Start Claude checking. Get the answer from Claris, not from a model's two-year-old memory of what Claris used to say.
Note: Updated 2 October 2026 for v2.1.0 of the Claude Skill, verified against FileMaker 26.0.3.
Takeaway
If you're using Claude for FileMaker development without a skill like this, you're building on uncertain ground. The Claris platform is too nuanced, too version-sensitive, and too fast-moving for 'good enough' AI knowledge.
This 'claris-filemaker-pro' skill is an initial step toward making AI assistance in the Claris ecosystem more reliable.
An Agent without a skill lies with confidence. This one checks first, and now it checks against the engine. This is a start . . .
Here's the download again, for those who just want the file: claris-filemaker-pro.skill or claris-filemaker-pro.zip . . .
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