Two defects found during live-cluster audit shakedown.
1. SQL validator false-positives on string literals
The forbidden-keyword check tokenized the entire query, including
contents of single-quoted string literals. CSS names like
'Call Forward-CSS', DN descriptions containing 'DELETE', or partition
names with 'INSERT' all tripped the validator even though the SQL
itself was clean read-only. Found while running impact analysis on
"Call Forward-CSS".
Fix: strip string literals (single-quoted, with '' as escape) into
whitespace before the forbidden-keyword tokenization. The cleaned
query returned to the caller still contains the literals — they're
only invisible to the analysis pass.
7 new tests covering: words inside literals (Call/Drop/Delete/etc.),
escaped quotes, multiple literals, and the critical case where a
forbidden keyword appears immediately after a literal.
2. CSS impact analysis missed primary device CSS + 7 other refs
Running route_devices_using_css("E911CSS") returned total=0 even
though E911CSS is configured in the cluster. Root cause: our
enumeration covered device.fkcallingsearchspace_{reroute,restrict,
refer,rdntransform} but not the primary device.fkcallingsearchspace
itself — the column the GUI sets when assigning a CSS to a phone.
The simple unsuffixed name didn't match our earlier "%css%" schema
filter (the actual column spells out "callingsearchspace").
Added 8 new reference categories:
device_primary_css — the big one
device_cgpn_unknown_css — calling-party-unknown
line_monitoring_css — devicenumplanmap monitoring CSS
gateway_h323_called_xform_css — H.323 gateway transform
gateway_sip_called_xform_css — SIP trunk transform
huntpilot_max_wait_css — hunt pilot queue handling
huntpilot_no_agent_css — hunt pilot queue handling
huntpilot_queue_full_css — hunt pilot queue handling
Re-running on live cluster:
Internal-CSS: 146 -> 163 refs (16 new device_primary_css matches)
Call Forward-CSS: previously rejected by validator -> 150 refs
E911CSS: still 0 — high-confidence orphan finding now
mcp-cucm-axl
Read-only MCP server for Cisco Unified CM 15 AXL — built for LLM-driven cluster auditing, with a particular focus on the Route Plan Report: partitions, calling search spaces, route patterns, translation patterns, called/calling party transformations, and digit-discard instructions.
Why this exists
CUCM's admin UI is great for one-config-at-a-time work but painful for audit/discovery questions like:
- "Which translation patterns rewrite the calling party number, and why?"
- "Which CSSs include the
Internal_PTpartition, in what order?" - "Show me every route pattern targeting the SIP trunk to the carrier."
- "Are there partitions defined but unreachable from any CSS?"
This server gives an LLM SQL access to CUCM's Informix data dictionary,
plus focused tools that bake in the right joins for routing-audit work.
Pair it with the sibling mcp-cisco-docs server and the LLM
gets vendor documentation alongside live cluster state — answering
"is our config consistent with Cisco's recommended baseline?" in a single
conversation.
Read-only by structural guarantee
The server never registers AXL write methods. There is no
executeSQLUpdate, no add*/update*/remove*/apply*/reset*/
restart* tool. Read-only is enforced by absence of write operations,
not by runtime sanitization. Defense-in-depth: SQL queries are also
client-side validated to begin with SELECT or WITH.
Setup
1. Configure environment
Edit .env (already gitignored):
AXL_URL=https://cucm-pub:8443/axl
AXL_USER=AxlUser
AXL_PASS=...
AXL_VERIFY_TLS=false # CUCM ships self-signed certs; default off
AXL_CACHE_TTL=3600 # 1 hour; 0 disables caching
AXL_WSDL_PATH= # optional explicit WSDL location
CISCO_DOCS_INDEX_PATH= # optional override for prompt enrichment
2. Bootstrap the AXL WSDL
Download the Cisco AXL Toolkit from your CUCM admin UI:
Application → Plugins → Find → "Cisco AXL Toolkit" → Download
Drop the resulting axlsqltoolkit.zip into the project directory. On first
launch, the server auto-extracts schema/15.0/ into ~/.cache/mcp-cucm-axl/wsdl/15.0/.
The zip is gitignored (Cisco-licensed; not redistributable).
Alternatives (in resolution order):
# A: explicit zip elsewhere
export AXL_WSDL_ZIP=/path/to/axlsqltoolkit.zip
# B: explicit WSDL file
export AXL_WSDL_PATH=/path/to/schema/15.0/AXLAPI.wsdl
# C: pre-populated cache directory
mkdir -p ~/.cache/mcp-cucm-axl/wsdl/15.0/
cp /path/to/schema/15.0/* ~/.cache/mcp-cucm-axl/wsdl/15.0/
3. Install + run
uv sync
uv run mcp-cucm-axl
Or via the bundled .mcp.json, automatically registered when Claude Code
opens this directory.
Tool surface
Foundational
| Tool | Purpose |
|---|---|
axl_version() |
Cluster version sanity check |
axl_sql(query) |
Execute a SELECT against Informix data dictionary |
axl_list_tables(pattern=None) |
Discover Informix tables |
axl_describe_table(name) |
Column metadata for one table |
cache_stats(), cache_clear(pattern=None) |
Cache plumbing |
Route plan
| Tool | Purpose |
|---|---|
route_partitions() |
All partitions with pattern + CSS-member counts |
route_calling_search_spaces(name=None) |
CSS list with ordered partitions |
route_patterns(kind=None, partition=None, filter=None) |
Route Plan Report — patterns + transformations |
route_inspect_pattern(pattern, partition=None) |
Deep dive: transforms, route filter, reachable-from CSS, full destination chain (route list → groups → gateways) |
route_lists_and_groups(name=None) |
Route list → route group → gateway chain (annotates Local Route Group placeholders) |
route_translation_chain(number, css_name=None) |
Wildcard-aware pattern matcher: evaluates X / ! / [0-9] / @ / \+ against the number and returns matches sorted by specificity |
route_digit_discard_instructions() |
DDI catalog |
route_device_pool_route_groups(device_pool_name=None) |
How each device pool resolves Local Route Group placeholders to actual gateway-bearing groups |
route_devices_using_css(css_name) |
Impact analysis: every reference to a CSS across line CFA/CFB/CFNA/CFUR/translation/MWI/shared, device-level CSSs, voicemail pilots, route lists |
route_filters(name=None) |
Route filter clauses + member rules (composed with @-pattern routes) |
Prompts
Schema-grounded conversation seeds. They pull relevant chunks from the
sibling cisco-docs index and embed them inline:
route_plan_overview— fresh audit conversation seedinvestigate_pattern(pattern, partition=None)— deep-dive a specific patternaudit_routing(focus="full")— comprehensive audit walkthroughcucm_sql_help(question)— catch-all for arbitrary SQL questions
Cache
Responses are cached in SQLite at ~/.cache/mcp-cucm-axl/responses/axl_responses.sqlite.
Cache survives restarts. Clear with cache_clear() after a known config change.
Notes
route_translation_chaindoes literal/prefix matching only. CUCM's actual matcher evaluates wildcards (X,!,[0-9], etc.) and selects the longest match. Treat results as "patterns to investigate" rather than "definitive route."- Pattern type codes (
tkpatternusage) used byroute_patterns(kind=...)are stable across CUCM versions but enumerated against thetypepatternusagetable at query time, so any cluster-specific custom types still work.