Project rename. The 'SP21+' identifier is more accurate than the
previous 'SP22+' label -- this fork specifically carries the SP21+
migration fixes (the upstream's system.execute_on_primary_thread()
removal and downstream API drift), and is forward-compat with later
SPs. The repo on GitHub has been renamed to
phobicdotno/Codesys-MCP-SP21-plus accordingly.
Substitutions (UTF-8 preserved this time -- prior PowerShell pass
mangled em-dashes via a Win-1252 round-trip):
- package.json: name codesys-mcp-sp22-plus -> codesys-mcp-sp21-plus,
bin entry, repository.url, homepage, description, author trailer
- README.md: title, banner, install + clone snippets, CLI invocations
- ARCHITECTURE.md: comparison-table column header + temp-dir prefix
- tests/TEST_OVERVIEW.md: title
- src/bin.ts: header comment + program().name()
- src/launcher.ts: SESSION_DIR_PREFIX
- src/types.ts: header comment
Compatibility phrase 'Works on SP19, SP21, and SP22+' and the technical
identifier 'SP22 Patch 1 fixes' (which name the actual CODESYS version)
were preserved -- those refer to CODESYS, not the project name.
README additions:
- Quick Start example switched from SP21 Patch 3 to SP22 Patch 1 to
match the more common modern install
- New 'Multiple CODESYS installations' subsection with worked
side-by-side example for SP21 (3.5.21.50) and SP22 (3.5.22.10) --
one named MCP server entry per install, called by name from Claude.
Documents the constraint that --codesys-path/--codesys-profile are
bound at server startup, that --detect lists installs, and that
config edits require a Claude Code restart
- Tool count corrected from 28 -> 37 in the Features bullets
- New Tools sections covering 10 previously-undocumented tools:
Version Anchor + Release Pipeline (bump_project_version,
release_project_version, read_running_version_online), Source
Mirror (mirror_export), and CODESYS Git PDE-gated (git_init,
git_status, git_commit, git_remote_add, git_branch_set_upstream_to,
git_push). Each row carries the actual operational gotchas
discovered during this session (UNC localRepoPath rejection,
push-without-upstream failure, optimizer stripping unreferenced
globals from the online symbol table, etc.)
- list_project_libraries + add_library row text updated to reflect
the post-fix behaviour (compiler-version capture; managed-overload
preference + resolution gate)
Local origin URL updated: phobicdotno/Codesys-MCP -> phobicdotno/Codesys-MCP-SP21-plus.
37/37 tests green.
Project identity rename. Concrete changes:
- package.json
- name: codesys-mcp-persistent -> codesys-mcp-sp22-plus (npm-safe;
'+' is not allowed in npm package names)
- description: prepended 'Codesys-MCP-SP22+' branding + brief
summary of the SP22+ fixes carried in this fork
- bin entry: codesys-mcp-persistent -> codesys-mcp-sp22-plus
- repository.url + homepage: now point at
github.com/phobicdotno/Codesys-MCP-SP22-plus (using -plus
spelling on the URL side; '+' would require URL-encoding)
- author: noted upstream + SP22+ fork attribution
- README.md: title + about-this-fork blurb + clone instructions
- tests/TEST_OVERVIEW.md: title
- ARCHITECTURE.md: comparison-table column header + temp-dir path
- src/bin.ts: file header + program().name()
- src/launcher.ts: SESSION_DIR_PREFIX (with note on backwards compat)
- src/types.ts: file header
Display name everywhere: 'Codesys-MCP-SP22+'.
npm package name: 'codesys-mcp-sp22-plus'.
Out of scope for this commit -- need user action:
- Local directory rename (C:/Users/karstein.kvistad/Codesys-MCP ->
...-SP22+) cannot be done while the persistent MCP is using dist/
from the current path; user can rename after shutting down VS Code.
- GitHub repo rename (phobicdotno/Codesys-MCP -> ...-SP22-plus or
...-SP22+) needs the github.com web UI; the package.json URLs
already point at the post-rename name so a 'git remote set-url
origin <new>' lines up after.
- MCP client config in .mcp.json or similar: the bin name changed
from 'codesys-mcp-persistent' to 'codesys-mcp-sp22-plus' -- update
any 'command' field that referenced the old name. (Local sessions
invoking node dist/bin.js directly are unaffected.)
37/37 tests still green after rename.
Three changes after deeper investigation against PLATEA Win V3:
1. The 'symbol' := 'read' attribute experiment didn't help. Reverted
bump_project_version's GVL template to plain VAR_GLOBAL +
qualified_only (matches what shipped originally, minus CONSTANT).
Comment updated to explain both why CONSTANT is wrong (compile-time
inlining) and why the symbol attribute alone wasn't enough (it
requires a Symbol Configuration object to do anything).
2. Real root cause for read_running_version_online's 'Invalid expression':
CODESYS strips unreferenced GVLs from the online symbol table at
compile time, regardless of attribute pragmas. The version anchor by
definition has no IEC code reading it, so the optimizer drops it.
GVL_Test.bRun reads fine despite no references because GVL_Test has
OTHER referenced variables; entire-GVL retention seems to be the
stripping unit, not per-variable.
Verified end-to-end: adding 'sVersionTag := _MCP_PROJECT_VERSION
.sVersion;' in PLC_PRG made the read return '1.4.1.0' on PLATEA.
3. Updated the read_running_version_online error message to surface
BOTH the (now-rare) CONSTANT case AND the (common) unreferenced-GVL
case, with the exact 2-line code snippet a user needs to paste into
their main program. The bump tool intentionally does NOT auto-inject
this -- modifying user code on every release was deemed too invasive.
Documented the requirement in TEST_OVERVIEW.md alongside the v5
sweep notes.
37/37 tests still green. v1.4.2.0 of MCPTest2 carries the working
PLC_PRG reference as the canonical demonstration.
Two related v5-sweep fixes for the online/runtime tool family:
1. Auto-login helper for headless mode
In headless mode each MCP call spawns a fresh CODESYS --noUI process,
so the login state established by connect_to_device dies before the
next call. Pre-fix, only connect_to_device and download_to_device did
their own login(); the other four (start_stop_application,
read_variable, write_variable, read_running_version_online) silently
failed in headless with 'Application not logged in.' (start/stop) or
'Invalid expression' (read/write). They worked in persistent mode
only because the login carried across calls.
Added ensure_logged_in(online_app, login_wait_seconds=30) to
ensure_online_connection.py. Idempotent: short-circuits via
online_app.is_logged_in (persistent mode is a no-op, no extra login
roundtrip). When not logged in, runs the same enum-probe + call-shape
probe + STABLE_STATES settle-wait pattern as connect_to_device.py.
Added to start_stop_application.py, read_variable.py,
write_variable.py, read_running_version_online.py.
2. _MCP_PROJECT_VERSION GVL emitted as plain VAR_GLOBAL, not CONSTANT
CODESYS inlines VAR_GLOBAL CONSTANT scalars at compile time and
strips them from the online symbol table. The whole point of
_MCP_PROJECT_VERSION.sVersion is to be readable live from the
running PLC, so CONSTANT was the wrong storage class.
read_running_version_online failed against EVERY project bumped via
the old template -- 'Invalid expression' on the runtime read.
Dropped CONSTANT from VERSION_GVL_DECLARATION_TEMPLATE in
bump_project_version.py. Existing projects auto-migrate on the next
bump because maintain_version_gvl()'s existing-GVL branch overwrites
textual_declaration with the (now non-CONSTANT) template. The string
is still effectively read-only at runtime -- only the bump tool
updates it.
read_running_version_online.py also got a more precise error message
that explicitly fingerprints the 'Invalid expression' failure mode
and points at the CONSTANT root cause. Useful for any user landing
on a project that pre-dates this fix.
Verified end-to-end against local CODESYS Control Win V3 (PLATEA, port
11740) on MCPTest2 v1.3.4.0:
- connect_to_device, get_application_state, download_to_device,
start_stop_application (both directions), read_variable
(PLC_PRG.watchdog1 = 225 ticking), write_variable (200 -> 204 in 4s
proves write took), disconnect_from_device: all 7 PASS.
- read_running_version_online failure reproduced (CONSTANT inlined),
fix landed -- next bump on MCPTest2 will validate.
37/37 unit/integration tests green. TEST_OVERVIEW.md updated with the
v5 device sweep, with the headless-mode deep-dive, and with the
broken-by-design notes on read_running_version_online.
Prior behaviour: lm.add_library(LIBRARY_NAME) was called with a string,
which always hits the placeholder overload of ScriptLibManObject.add_library
(see helpme-codesys.com "ScriptLibManObject" / local SP22 stub
ScriptLib/Stubs/scriptengine/ScriptLibManObject.pyi). If the named
placeholder is not registered in the IDE, the resulting reference fails
to resolve at load time and the next project open throws
Library Manager: Error: Could not open library 'X'.
(Reason: The placeholder library 'X' could not be resolved.)
after which script_engine.projects.primary returns None and the project
is effectively bricked until the binary is reverted. add_library reported
SUCCESS in this scenario.
Fix:
1. Pre-resolve LIBRARY_NAME via the IDE-level
library_manager.find_library(name) global. If found, pass the
resulting ManagedLib to lm.add_library(...) -- the V3.5.5.0 ManagedLib
overload which produces a managed reference instead of a placeholder.
2. After the add, walk lm.references to locate the new entry and verify
it resolved (managed -> always; placeholder -> non-empty
effective_resolution per ScriptPlaceholderReference in the stub).
3. If the reference did not resolve, call lm.remove_library(name) to back
out the bad reference and refuse to save the project, returning an
actionable error instead.
Also tightened the libman lookup to use the documented
has_library_manager / get_library_manager() container API
(ScriptLibManObjectContainer in the stub) instead of name-searching for
"Library Manager" as a tree node, matching what list_project_libraries.py
already does. The legacy name-search fallback is preserved for older SPs.
Regression test added in tests/integration/e2e.test.ts asserting the
rendered script template carries the resolution gate, the managed-overload
preference, the back-out call, and that primary_project.save() in the
add_library body lives downstream of the _is_resolved gate.
Followup: lm.remove_library(name) is documented for SP22 and is the
clean back-out path. On SPs that lack remove_library (none observed in
the 3.5.21+ docs but possible on truly old branches) the script reports
the constraint and exits non-zero rather than silently saving a bad
reference.
Three changes:
1. Fix the bench harness's set_pou_code case. The previous version
passed POU_PATH / DECLARATION_CODE / IMPLEMENTATION_CODE, but the
script template expects POU_FULL_PATH / DECLARATION_CONTENT /
IMPLEMENTATION_CONTENT. Plus the recently-added SET_DECLARATION /
SET_IMPLEMENTATION boolean flags from 35abc8c. With these
corrections, set_pou_code passes for the first time in the bench.
2. Add bench-results-v5.json from a fresh persistent-mode run on
MCPTest2 v1.3.4.0. All 10 cases PASS.
3. Update TEST_OVERVIEW.md with the v5 numbers alongside the v1
historical numbers. v5 is ~2x faster across the board than v1
(likely the cumulative effect of the ScriptManager cache removal +
SP22 Patch 1 IPC improvements). first-cold open_project is slower
than v1 (10.6 s vs 7.7 s) -- one-shot, noise probably; warm
already-open call dropped from 740 ms to 314 ms.
The v5 set_pou_code pass is the third end-to-end signal that the
omitted-decl wipe fix is good (after the e2e regression test and the
live PLC_PRG restoration earlier today).
Bug: calling set_pou_code with implementationCode only (declarationCode
omitted) would wipe the POU's PROGRAM/VAR...END_VAR block in the binary.
After such a call mirror_export classified the POU as 'UNKNOWN' (no
PROGRAM/FUNCTION_BLOCK keyword in the empty declaration), and the var
block disappeared from the .st mirror file.
Root cause: the TS wrapper substituted '' (empty string) into the Python
template when declarationCode was undefined, giving DECLARATION_CONTENT
= "". The Python script then took the truthy-ish branch (empty string
is not None) and called decl_obj.replace('') -- wiping textual_decl.
Fix: pass explicit SET_DECLARATION / SET_IMPLEMENTATION boolean flags
from the TS wrapper, gate the replace() calls on those flags. Empty
string remains a valid intentional value (caller wants to wipe).
- Reproduced on MCPTest2: PLC_PRG declaration block was wiped between
v1.3.0.0 and v1.3.1.0 by exactly this code path.
- Regression test added in tests/integration/e2e.test.ts covering the
omitted-declarationCode path.
- Existing set_pou_code test extended to assert SET_DECLARATION /
SET_IMPLEMENTATION are emitted in the rendered script.
- Bumped status from "fixed (factory fallback)" to "fixed in c87f3a9
(4-iteration debug saga)" with the v1->v4 iteration table:
* v1 2607063: name= kwarg -- FAIL (SP22 wants foldername)
* v2 e07f281: positional + foldername= -- FAIL (silent None return)
* v3 32e6120: project-level + cache removal -- FAIL (still None=fail)
* v4 c87f3a9: walk children to detect side-effect success -- PASS
- Real root cause documented: SP22's create_folder returns void; the
fix verifies by walking parent.get_children(False).
- Side benefit from v3 (ScriptManager cache dropped) noted as the
hot-reload mechanism that made v4 reachable in one debug session.
- "Lesson for future fork work" callout: probably applies to other
create_* methods too, audit pending.
- Inventory table row for create_folder updated with the c87f3a9
link + a more accurate description of the strategy chain.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
create_folder v2 (positional foldername) returned None silently against
the SP22 Application object -- no exception raised, no folder created.
Investigation showed:
- ScriptObject.create_folder(foldername) is documented to "create a
folder in the structured view of the parent node", but on Application
specifically it's a silent no-op (the structured view isn't pinned to
POU view there).
- ScriptProject.create_folder(foldername, structured_view=None) on the
project itself with explicit SV_POU GUID
({21AF5390-2942-461a-BF89-951AAF6999F1}) is the documented and
reliable pathway -- the resulting folder appears under Application
in the IDE tree because that's where SV_POU lives.
v3 fix: try strategies in order until one returns non-None:
(1) primary_project.create_folder(name, SV_POU_GUID) -- new, primary
(2) parent.create_folder(name) positional -- pre-SP21 path
(3) parent.create_folder(foldername=name) -- alt keyword
(4) primary_project.create_folder(name) -- default view
(5) parent.create_object(typeUuid='85d1215e-...') -- alt factory
(6) parent.add(script_engine.types.IecFolder, name=name) -- legacy
Each strategy guards on hasattr + return-value-not-None, so a silent
no-op falls through instead of being mistaken for success.
ScriptManager: dropped the in-memory template cache. Each loadTemplate
call now reads the .py from disk fresh. Cost: ~1ms per call vs ~1.5s
of CODESYS execution time -- invisible. Win: edits to dist/scripts/
take effect without an MCP restart, which makes iterating on script-
side fixes (like this very create_folder loop) much faster. Existing
"cache hit" unit test rewritten as "two loads return equal content".
tests/test-fixes.mjs: standalone harness that drives a single persistent
CODESYS through HeadlessExecutor + CodesysLauncher to verify the four
broken-tool fixes end-to-end. Useful for regression-testing without
needing a vsc reboot loop. Currently only smoke-tests
create_folder + compile + cross-project; expand as more fixes need
verification.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
- Headline result table at the top: persistent is 15-24x faster than
headless across all CODESYS-roundtripping tools. Numbers are from a
fresh bench-results.json run on MCPTest2.
- Updated mode primer with measured first-call vs warm-call costs:
persistent first launch ~14.6s, subsequent calls ~1.5s; headless
first cold call ~58s, warm calls ~22s.
- Inventory table: replaced "typical" estimates with measured numbers
for the 9 tools the bench covers.
- Deep-dive section: each broken tool now marked "fixed in 2607063"
with concise summary of the fix that landed (instead of "proposed
fix"). Removed the long pre-fix code blocks since they're in the
commit history now.
- Status legend: create_folder, compile_project, get_compile_messages,
connect_to_device, open_project all flipped from broken to fixed
(with caveats: some need PLC or runtime verification).
- Footnote about set_pou_code bench-harness failure (multi-line code
through triple-quoted-string interpolation -- not a tool bug).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
create_folder SP21+ fallback, ensure_project_open cross-project switch)
+ bench results
compile_project.py + get_compile_messages.py:
- IronPython 2.7's json.dumps cannot serialize System.Int64-backed `long`
values, which is what CODESYS's compile-message objects expose as
line_number / position. Added _coerce_int + _coerce_str helpers and a
shared _build_message_entry function. Three duplicated message-building
blocks collapsed into single helper calls.
- Defensive `try: json.dumps(...) except TypeError: json.dumps(default=str)`
so a stray field that slips past the helpers doesn't kill the emit.
connect_to_device.py:
- SP21+ may expose the login enum as LoginMode rather than
OnlineChangeOption. Extended the candidate sweep to probe both
script_engine.LoginMode and script_engine.OnlineChangeOption AND
online_app.LoginMode/OnlineChangeOption (some builds attach it to the
app object). Added "OnlineChange" + "Login" + "Download" to the
preferred-priority list. Added a 3-arg call shape variant for SPs
that take (mode, secondary-mode, force-bool).
create_folder.py:
- parent_object.create_folder() is no longer exposed on every parent type
in SP21+. Added two fallback factories tried in order:
1. parent.create_object(typeUuid='85d1215e-6520-4983-9a55-2d39d1f24cb4', name=...)
2. parent.add(script_engine.types.IecFolder, name=...)
with detailed warnings when each path fails. Final TypeError now lists
every factory tried so a future SP rotation surfaces clearly.
ensure_project_open.py:
- Uncommented the close-prior-project branch (was a TODO since the
initial fork). Cross-project switches in a persistent CODESYS now do
save() -> close() -> 500ms pump -> open(target). Without this,
projects.open against a different already-primary project fails
intermittently on file lock contention or pops a "project in use"
modal that freezes the IDE thread.
- save() is best-effort: if it raises (transient lock, save-as required)
we still proceed with close + open rather than getting stuck in a
half-switched state forever.
tests/bench-results.json:
- Captured timings from a clean run on MCPTest2 (PLCWinNT, 5 lib refs,
~12 POUs). 9 tools x 2 modes x iterations.
Headers (mean ms): persistent vs headless --
open_project 7700 vs 40041 (~5x; first call cold)
mirror_export 1547 vs 23723 (~15x)
list_project_libraries 1565 vs 23322 (~15x)
get_all_pou_code 1607 vs 23376 (~15x)
save_project 2095 vs 23321 (~11x)
create_pou (FB) 1540 vs 23903 (~16x)
delete_object 1544 vs 27420 (~18x)
bump_project_version 1540 vs 30678 (~20x)
bump_project_version #2 1556 vs 37769 (~24x)
- set_pou_code FAILED in both modes -- bench harness param-shape issue
(multi-line code passed verbatim to triple-quoted-string interpolation
doesn't survive the round-trip). Tool itself works fine through the
MCP tool call path; bench needs to escape newlines / use the same
prepareScriptWithHelpers shape the server uses. Filed for follow-up.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
TEST_OVERVIEW.md: complete tool inventory (37 tools), each tagged
working / broken with status notes and per-mode timing characteristics.
Mode primer up top explains the per-call vs first-call cost asymmetry.
Deep-dive on every broken tool with proposed fixes:
- create_folder: parent_object.create_folder() not exposed in SP21+;
fall back to create_object(typeUuid=...) or types.IecFolder.
- compile_project / get_compile_messages: IronPython 2.7 json.dumps
can't serialize System.Int64 (line_number / position fields).
Fix is a _coerce_int helper applied uniformly.
- connect_to_device: SP21+ may expose the login enum as LoginMode
instead of OnlineChangeOption. Extend the candidate sweep over
multiple enum sources, with priority on TryOnlineChange-equivalents.
- open_project (cross-project switch): ensure_project_open has the
"close prior project" branch commented out; uncomment with a
save+close+delay sequence and silent-mode guard.
list_project_libraries is flagged as ✅ working in current SP22
(historical entries in the project memory should be cleared).
bench.mjs: standalone benchmark harness driving HeadlessExecutor and
CodesysLauncher directly (no MCP server in the loop). Copies the source
.project to a temp dir so write tools don't mutate the original. Covers
9 tools (read-only + write-revertible) with configurable iterations,
emits markdown to stdout + JSON to --out.
Run with:
node tests/bench.mjs --modes headless,persistent --iterations 2
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
v0.3.0 returning-watcher architecture — background thread polls for commands
and marshals execution onto the CODESYS UI thread, keeping the IDE fully
responsive between operations. File-based IPC with atomic writes, async mutex
command serialization, headless fallback, and 35 passing tests.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
