Oracle Forms MCP

An MCP server that serves the content of Oracle Forms modules (.fmb forms, .mmb menus, .pll PL/SQL libraries, .olb object libraries) found in a directory, so AI assistants can inspect blocks, items, triggers, program units, and raw object XML without opening Forms Builder.

Built as a Kotlin Multiplatform core (pure @Serializable models and ports) with a JVM MCP server on top: declarative tool adapters over a single FormsService, stdio and HTTP transports, and a fingerprint-based on-disk cache. Oracle tool conversion feeds a streaming StAX parser that turns Forms XML into a structured index.

Why

Oracle Forms applications from the 1990s–2000s are still running critical business processes, but their logic is locked inside binary .fmb/.pll modules that only Forms Builder can open. That makes them opaque to modern AI tooling and painful to review, document, or migrate.

Oracle Forms MCP turns those modules into structured, queryable content so an AI assistant can:

• Understand a legacy app — enumerate blocks, items, triggers, and program units without a Forms IDE.

• Review & document PL/SQL — pull decoded trigger and program-unit bodies straight into the model's context.

• Assist modernization — feed decades-old business logic to an assistant for migration to APEX, Java, or a rewrite, and search across every module's source.

• Capture & retain knowledge — let the assistant record notes, tags, and cross-references on individual elements that persist across sessions and re-indexing, building up a durable map of a form no one fully remembers.

It is aimed at developers and teams doing Oracle Forms modernization, reverse engineering, code review, and documentation — anyone who needs to read Forms logic faster than opening it by hand.

Related MCP server: RenderDoc MCP Server

See it work

A typical session against the bundled sample-forms directory:

You:  What does ORDERS.fmb do?
AI →  list_modules                 → ORDERS.fmb (NOT_CACHED), MAINMENU.mmb, UTILS.pll …
AI →  fetch_module ORDERS.fmb      → converted + indexed (2 blocks, 3 triggers, 3 program units)
AI →  get_module_overview ORDERS   → blocks, triggers, LOVs, record groups, windows, canvases …
You:  Show me the validation logic on the ORDERS block.
AI →  list_triggers block=ORDERS   → WHEN-VALIDATE-ITEM (on ORDER_ID), WHEN-VALIDATE-RECORD
AI →  get_trigger ORDERS WHEN-VALIDATE-ITEM  → the decoded PL/SQL body
You:  Where else is the CALC_TOTAL procedure called?
AI →  search_source "calc_total" scope=plsql  → hits across triggers and program units
You:  That validation is the legacy pre-2010 path — note it so we remember.
AI →  annotate_element ORDERS trigger WHEN-VALIDATE-ITEM kind=note "Legacy pre-2010 validation path" → saved
      (next session)  get_trigger ORDERS WHEN-VALIDATE-ITEM → body + the stored note inline

How it works

1. list_modules scans the configured --forms-dir (non-recursive) and reports each module's cache status: NOT_CACHED, CACHED, STALE (source changed on disk), or SOURCE_MISSING.

2. fetch_module produces the module's text form in the cache and indexes it:

   • ORACLE_HOME set — binaries are converted with the Oracle tools in %ORACLE_HOME%\bin: frmf2xml for .fmb/.mmb/.olb (XML), frmcmp_batch (Module_Type=LIBRARY Script=YES) for .pll (a .pld text dump).

   • ORACLE_HOME not set — pre-converted files are expected next to the modules (orders_fmb.xml, dupes_fmb.xml, mainmenu_mmb.xml, objects_olb.xml, utils.pld) and copied into the cache.

3. A single StAX pass parses the XML into a structured index (blocks with items, triggers with decoded PL/SQL, program units, LOVs, record groups, windows, canvases, …). PL/SQL bodies are extracted to .sql sidecar files; every named XML element gets a line-range reference so get_object_xml can slice it back out of the converted file.

4. The other tools read the cached index. Caching is fingerprint-based (size + mtime + sha256 of the source file): editing a module marks it STALE and read tools ask for a re-fetch.

5. annotate_element and relate_elements let the assistant write durable meta-information back about individual elements (notes, tags, summaries, classifications, cross-references). This is kept in a separate store — not the derived index — so it survives re-fetching, and the read tools surface it inline. An annotation made before a source change is flagged, never dropped.

Tools

Annotations

Meta-information the assistant records back about an element rather than reads from it — semantic notes, tags, classifications, and cross-reference relations. It is persisted in a durable store, kept separate from the derived index (not in the protocol _meta field), so it survives fetch_module re-indexing and is served back to later sessions. Each entry carries its author and is flagged staleAgainstSource when it predates the module's current source, so a note is never silently dropped. The read tools above (get_module_overview, get_block, get_trigger, get_program_unit, get_object_xml) surface an element's annotations inline.

Plus a resource per cached module (oracleforms://ORDERS.fmb/index), the oracleforms://{module}/index and oracleforms://{module}/annotations resource templates, and an explain_module prompt.

Quick start

Requires a JRE 21+. Build and install:

gradlew :server:installDist

Register with Claude Code (stdio):

claude mcp add oracle-forms -- server/build/install/server/bin/server --forms-dir C:\path\to\forms

The published image runs the server over stdio with no local build. Point the volume mount at your forms directory (copy-mode: the pre-converted *_fmb.xml/*.pld files must sit next to the modules — see Docker).

Claude Desktop (claude_desktop_config.json) and Cursor (~/.cursor/mcp.json) use the same shape:

{
  "mcpServers": {
    "oracle-forms": {
      "command": "docker",
      "args": ["run", "-i", "--rm",
               "-v", "ofmcp-cache:/home/mcp/.cache", "-v", "/path/to/forms:/forms",
               "ghcr.io/aoreshkov/oracle-forms-mcp", "--forms-dir", "/forms"]
    }
  }
}

VS Code (.vscode/mcp.json) uses a servers key instead:

{
  "servers": {
    "oracle-forms": {
      "command": "docker",
      "args": ["run", "-i", "--rm",
               "-v", "ofmcp-cache:/home/mcp/.cache", "-v", "${workspaceFolder}/forms:/forms",
               "ghcr.io/aoreshkov/oracle-forms-mcp", "--forms-dir", "/forms"]
    }
  }
}

The ofmcp-cache named volume keeps the parsed-module cache and — more importantly — the durable annotation store across container restarts; --rm removes the container but not a named volume. Drop it and the notes/tags/relations the assistant records won't survive the next run. See Docker for the bind-mount variant and its one-time chown.

Prefer the native launcher? Swap "command": "docker", "args": [...] for "command": "/abs/path/to/server/build/install/server/bin/server", "args": ["--forms-dir", "/abs/path/to/forms"].

Try it without any Oracle installation using the bundled fixtures:

server --forms-dir sample-forms

HTTP transport:

server --forms-dir C:\forms --transport http --port 3000   # endpoint: http://127.0.0.1:3000/mcp

Docker (copy-mode only)

A container image is published to ghcr.io/aoreshkov/oracle-forms-mcp. Oracle's frmf2xml / frmcmp_batch binaries are proprietary and not bundled, so the image works only in copy-mode: the modules you mount must already have their pre-converted text form (*_fmb.xml/*_mmb.xml/*_olb.xml/*.pld) sitting next to them. For live .fmb/.pll conversion, run the server on a host with an Oracle Forms installation (ORACLE_HOME set).

docker run -i -v /path/to/forms:/forms ghcr.io/aoreshkov/oracle-forms-mcp --forms-dir /forms

Persisting the cache and annotations. Without a volume, the cache and the durable annotation store live in the container's writable layer and are discarded when it exits. Mount a volume at /home/mcp/.cache to keep them across runs:

docker run -i -v ofmcp-cache:/home/mcp/.cache -v /path/to/forms:/forms \
  ghcr.io/aoreshkov/oracle-forms-mcp --forms-dir /forms

A named or anonymous volume inherits the image's non-root ownership (uid 10001) and just works. A host bind mount does not — Docker never chowns the target — so run chown 10001 /host/cache once on the host first, or redirect the writes with --cache-dir / --annotations-dir onto a path the container user can write.

Options

--forms-dir <path>          Directory containing the Forms modules (or pass it positionally)
--transport stdio|http      Transport (default: stdio)
--port <int>                HTTP port (default: 3000)
--allowed-host / --allowed-origin   Extra HTTP hosts/origins (localhost-only by default)
--cache-dir <path>          Cache override (default: OS cache dir + /oracle-forms-mcp)
--annotations-dir <path>    Durable annotation store (default: <cache dir>/annotations)
--conversion-timeout <sec>  Kill a stuck conversion (default: 120)

Cache

%LOCALAPPDATA%\oracle-forms-mcp (Windows), ~/Library/Caches/oracle-forms-mcp (macOS), $XDG_CACHE_HOME/oracle-forms-mcp (Linux). One directory per module:

ORDERS.fmb/
  converted/orders_fmb.xml      converted (or copied) text form
  plsql/triggers/*.sql          decoded trigger bodies
  plsql/program-units/*.sql     decoded program units
  plsql/menu-items/*.sql        menu-item command bodies (menu modules)
  index.json                    the structured index

Safe to delete at any time; modules are simply re-fetched.

Annotations are not part of this derived cache. They live in a separate annotations/ store (one NAME.ext.json per module, defaulting to <cache dir>/annotations, overridable with --annotations-dir), so deleting a module's cache entry — or re-fetching it — leaves the notes, tags, and relations you recorded intact.

Notes on the Oracle tools

• frmf2xml writes its output into the process working directory; the server runs it with the module's cache dir as cwd and passes OVERWRITE=YES USE_PROPERTY_IDS=NO.

• frmcmp_batch is preferred over frmcmp (headless); the server passes Script=YES Batch=YES Logon=NO and augments FORMS_PATH with the forms dir so attached libraries resolve.

• Forms tools have unreliable exit codes — success is judged by the output file existing, being non-empty, and being newer than the invocation; failures surface the tool's output tail.

• .pld files may be written in the client NLS charset; the parser reads UTF-8 with a windows-1252 fallback (set NLS_LANG accordingly if you see mojibake).

Development

gradlew build          # compile + all tests (no Oracle installation needed)
gradlew updateKotlinAbi   # refresh the ABI dump (core/api/*.api) after public API changes
gradlew :server:run --args="--forms-dir sample-forms"

Converter behavior is tested against a fake ORACLE_HOME (stub scripts); the full copy-mode pipeline is covered end-to-end by FormsServiceIntegrationTest against the bundled fixtures.