neo4j-migration-skill

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name: neo4j-migration-skill description: Migrates Neo4j driver code and Cypher queries from older versions (4.x, 5.x) to current (2025.x/2026.x, Cypher 25). Covers Python, JavaScript/Node.js, Java, .NET, and Go drivers — package renames, removed APIs, version requirements, diff-ready fixes. Also handles Cypher syntax migration — QPE paths, CALL subqueries, id() → elementId(), PERIODIC COMMIT → CALL IN TRANSACTIONS, and all Cypher 25 removals. Does NOT write new Cypher queries — use neo4j-cypher-skill. Does NOT cover DB administration or server ops — use neo4j-cli-tools-skill. Does NOT provision new Neo4j instances — use neo4j-getting-started-skill. allowed-tools: WebFetch Bash version: 1.0.11

When to Use

• Upgrading driver dependency from 4.x or 5.x to 6.x
• Migrating Cypher queries to Cypher 25 syntax
• Fixing deprecated API warnings after a driver or Neo4j version bump
• Auditing a codebase for removed/deprecated Neo4j APIs before upgrading

When NOT to Use

• Writing new Cypher queries → neo4j-cypher-skill
• DB admin (backup, restore, import, cypher-shell) → neo4j-cli-tools-skill
• Starting fresh → neo4j-getting-started-skill
• GDS algorithm migration — not covered here; consult GDS release notes

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Entry Criteria

Before starting, ask:

1. Target Neo4j version — needed to select Cypher dialect and driver version
2. Languages in use — scan package.json, requirements.txt, pom.xml, *.csproj, go.mod
3. Current driver versions — read from dependency files; do NOT guess

If target is >= 2025.06: ask whether Cypher 5 or Cypher 25 dialect will be used (both supported; Cypher 25 is the new default).

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Step 1 — Scan Codebase

# Find Cypher strings (queries embedded in source)
grep -rn "MATCH\|MERGE\|CREATE\|CALL\|RETURN" --include="*.py" --include="*.js" \
  --include="*.ts" --include="*.java" --include="*.cs" --include="*.go" \
  --include="*.cypher" --include="*.cql" . | grep -v ".git"

# Find dependency files
find . -name "requirements*.txt" -o -name "package.json" -o -name "pom.xml" \
  -o -name "*.csproj" -o -name "go.mod" | grep -v ".git" | grep -v node_modules

Collect findings before modifying anything. List all deprecated patterns found.

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Step 2 — Cypher Migration (4.x / 5.x → Cypher 25)

Apply to every Cypher string, .cypher file, OGM/SDN @Query annotation, and template literal.

Complete Substitution Table

Old syntax	Cypher 25 replacement	Notes
[:REL*1..5]	(()-[:REL]->()){1,5}	QPE quantifier group
[:REL*]	(()-[:REL]->()){1,}	Unbounded QPE
[:REL*0..5]	(()-[:REL]->()){0,5}	Zero-hop allowed
shortestPath((a)-[*]->(b))	SHORTEST 1 (a)(()-[]->()){1,}(b)	QPE shortest path
allShortestPaths((a)-[*]->(b))	ALL SHORTEST (a)(()-[]->()){1,}(b)	QPE all-shortest
id(n)	elementId(n)	Returns string, not int
CALL { WITH x ... }	CALL (x) { ... }	Explicit import syntax
PERIODIC COMMIT	CALL (...) { ... } IN TRANSACTIONS OF 1000 ROWS	Batched writes
-- comment	// comment	SQL comment invalid
SET n = r (structural val)	SET n = properties(r)	Extract map first
MERGE (a {x:1})-[:T]->(b {x:a.x})	Rewrite — cross-entity MERGE refs disallowed	Split into MATCH+MERGE
CREATE INDEX ... OPTIONS { indexProvider: ... }	Remove indexProvider from OPTIONS	Provider selection removed
db.create.setVectorProperty(...)	Use native VECTOR property type	Procedure removed
dbms.upgrade() / dbms.upgradeStatus()	Use cypher-shell :sysinfo	Procedures removed
USE composite.'1'	USE `composite.1`	Backtick entire qualified name
RETURN 1 as my$Identifier	RETURN 1 as `my$Identifier`	$ removed from unescaped ids

Vector Index Queries (version-branched)

Version	Syntax
Neo4j < 2026.01	CALL db.index.vector.queryNodes(idx, k, $emb) YIELD node, score
Neo4j >= 2026.01	SEARCH n IN (VECTOR INDEX idx FOR $emb LIMIT k) SCORE AS score

Cypher Dialect Prefix Rule

• Target >= 2025.06, dialect = Cypher 25: prepend CYPHER 25 to every top-level query
• Target >= 2025.06, dialect = Cypher 5: prepend CYPHER 5 (keeps deprecated forms working)
• Target 4.x or 5.x: no prefix needed; fetch changelog per references/cypher-queries.md

id(n) → elementId(n) Caveats

elementId() returns a string (e.g., "4:abc123:0"), not an integer. Fix downstream code that stores or compares it as int. Do NOT use elementId() values for numeric operations.

- WHERE id(n) = $nodeId   # $nodeId was integer
+ WHERE elementId(n) = $nodeId  # $nodeId must now be string

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Step 3 — Driver Migration

Pick the section(s) matching languages found in Step 1.

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Python Driver (5.x → 6.x)

Min requirements: Python >= 3.10, neo4j package (6.0+, released Jan 12 2026)

Package Rename — do this first

# requirements.txt
- neo4j-driver>=5.0.0
+ neo4j>=6.0.0

neo4j-driver package is deprecated since 6.0 and receives no further updates.

Removed APIs

Old	New	Notes
session.read_transaction(fn)	session.execute_read(fn)
session.write_transaction(fn)	session.execute_write(fn)
session.last_bookmark()	session.last_bookmarks()	Returns Bookmarks (plural)
Bookmark class	Bookmarks class
TRUST_ALL_CERTIFICATES	trusted_certificates=TrustAll()
TRUST_SYSTEM_CA_SIGNED_CERTIFICATES	trusted_certificates=TrustSystemCAs()
neo4j.conf, neo4j.data modules	Removed — use top-level neo4j.*

Resource Management Change

Drivers and sessions no longer auto-close on GC. Add explicit cleanup:

- driver = GraphDatabase.driver(URI, auth=(USER, PASS))
- # used without explicit close
+ with GraphDatabase.driver(URI, auth=(USER, PASS)) as driver:
+     with driver.session(database="neo4j") as session:
+         ...

Or call .close() explicitly. Repeated .close() is a no-op.

Error Handling Changes

Old exception	New exception	Trigger
ClientError (for timeout)	ConnectionAcquisitionTimeoutError	Acquisition timeout
AuthError (invalid config)	ConfigurationError	Invalid auth params
ValueError raised for Query obj	TypeError	Passing Query to Transaction.run

Key APIs Unchanged

execute_query(), GraphDatabase.driver(), neo4j+s:// URI, auth=(user, pw), session run().

Full changelog: references/python-driver.md

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JavaScript / Node.js Driver (5.x → 6.x)

Min requirements: Node.js >= 18 (check engines in driver's package.json); package neo4j-driver

Removed APIs

Old	New	Notes
session.readTransaction(fn)	session.executeRead(fn)
session.writeTransaction(fn)	session.executeWrite(fn)
session.lastBookmark()	session.lastBookmarks()	Returns array
resultSummary.updateStatistics	resultSummary.counters
driver.verifyConnectivity() → ServerInfo	driver.getServerInfo() → ServerInfo	verifyConnectivity() now returns void

Deprecated in 6.0 (will be removed in 7.0)

Old	New
isRetriableError(err)	isRetryable(err)
neo4jError.retriable	neo4jError.retryable
notificationCategory	notificationClassification

Integer Handling

Neo4j integers map to neo4j.Integer (64-bit). Use .toNumber() or .toInt() for arithmetic. Large values (> 2^53) lose precision — store as string with .toString().

// Safe pattern
const count = record.get('count').toNumber()

Full changelog: references/javascript-driver.md

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Java Driver (5.x → 6.x)

Min requirements: Java 21; Maven org.neo4j.driver:neo4j-java-driver:6.x

Maven Coordinates

<dependency>
  <groupId>org.neo4j.driver</groupId>
  <artifactId>neo4j-java-driver</artifactId>
- <version>5.x.x</version>
+ <version>6.0.0</version>
</dependency>

Removed APIs

Removed	Replacement	Notes
RxSession / RxTransaction	Use async AsyncSession or sync Session	Reactive API removed
Bookmark multi-value constructor	Bookmark.from(iterable)
session.readTransaction(fn)	session.executeRead(fn)
session.writeTransaction(fn)	session.executeWrite(fn)
TrustStrategy.certFile()	TrustStrategy.trustCustomCertificateSignedBy(path)
Notification.severity()	Notification.severityLevel()	Returns typed enum

Dependency Note (BOM)

neo4j-java-driver-bom no longer imports netty-bom as of 6.0.1. If using Netty native transport, add explicit netty-bom import.

Logging

Legacy Logging API deprecated → configure System.Logger instead.

Full changelog: references/java-driver.md

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.NET Driver (5.x → 6.x)

Min requirements: .NET 8, 9, or 10 (.NET Standard 2.1 dropped); NuGet Neo4j.Driver 6.x

NuGet Package

- <PackageReference Include="Neo4j.Driver" Version="5.*" />
+ <PackageReference Include="Neo4j.Driver" Version="6.*" />

Neo4j.Driver.Signed no longer receives updates — switch to Neo4j.Driver (now signed).

Removed APIs

Removed	Replacement	Notes
ILogger	INeo4jLogger	Interface renamed
ConfigBuilder.WithIpv6Enabled()	Remove call — IPv6 always enabled
Config.Ipv6Enabled property	Remove — always true
Simple driver	Use standard IDriver	Removed entirely

Full changelog: references/dotnet-driver.md

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Go Driver (5.x → 6.x)

Min requirements: Go 1.24; module github.com/neo4j/neo4j-go-driver/v6

go.mod Update

- require github.com/neo4j/neo4j-go-driver/v5 v5.x.x
+ require github.com/neo4j/neo4j-go-driver/v6 v6.x.x

Update all imports from /v5/ to /v6/.

Removed APIs and Replacements

Old	New	Notes
neo4j.NewDriver(...)	neo4j.NewDriverWithContext(...)	Context-aware; or just use neo4j.NewDriver (now has context)
neo4j.Config struct	config.Config	Import github.com/neo4j/neo4j-go-driver/v6/neo4j/config
neo4j.ServerAddressResolver	config.ServerAddressResolver
neo4j.LogLevel / neo4j.ERROR etc.	log.Level / log.ERROR	Import neo4j/log sub-package
log.Console	log.ToConsole
log.Void	log.ToVoid
neo4j.Single[T]	neo4j.SingleT[T] (still present; context variant preferred)
neo4j.Driver interface	neo4j.DriverWithContext	*WithContext variants are now primary
neo4j.Session interface	neo4j.SessionWithContext
Config.RootCAs field	Config.TlsConfig	Pass *tls.Config directly
Notification constants (old pkg)	notifications.* equivalents	Import neo4j/notifications

Context API Consolidation

In v6, neo4j.NewDriverWithContext is the canonical constructor. The old *WithContext method names are deprecated (targeted for removal in v7) — base names now include context by default.

- driver, err := neo4j.NewDriver(uri, neo4j.BasicAuth(user, pass, ""))
+ driver, err := neo4j.NewDriverWithContext(uri, neo4j.BasicAuth(user, pass, ""))

Full migration guide: references/go-driver.md

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Step 4 — Version Compatibility Matrix

Neo4j version	Cypher dialect	Driver 6.x compatible	Notes
4.4 LTS	Cypher 4	Yes (bolt compat)	Support ended Nov 2025
5.26 LTS	Cypher 5	Yes	Supported until Nov 2028
2025.01–2025.05	Cypher 5	Yes	CalVer era begins
2025.06+	Cypher 5 or 25	Yes	Cypher 25 new default
2026.01+	Cypher 25	Yes	SEARCH clause available
2026.07.0	Cypher 25	Yes	Skip this patch — block-format UTF-8 regression makes trim() fail queries and corrupt stored strings; upgrade target is 2026.07.1
2026.08+	Cypher 25	Yes	UUID type + string interpolation added; UUID properties require driver >= 6.2 (Python >= 6.3) — older drivers return placeholder MAP and warn 03N95; 2026.08 bundles Java driver 6.2.1; skip 2026.08.0 (query-failure bug) — target 2026.08.1+
2026.09+	Cypher 25	Yes	SEARCH clause accepts FULLTEXT INDEX; page cache reserves full server.memory.pagecache.size at startup

Store format: no changes between 4.4 and 2026.x. block format default for new Enterprise dbs since 5.22. high_limit and standard deprecated in 5.23, removed after 2026 LTS — Neo4j refuses to start on a high_limit store after that LTS; run offline neo4j-admin database migrate --to-format=block <db> on or before the LTS.

Server JVM: 2026.x runs on Java SE 21 or 25; Java 21 support ends with the 2026 LTS — move servers to Java 25 [2026.08 deprecation].

No downgrades supported — take a backup before any server upgrade.

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Step 5 — Test After Migration

# Python: run with dev mode to surface all deprecation warnings
python -W error::DeprecationWarning -m pytest tests/

# JS: run tests
npm test

# Java
mvn test

# .NET
dotnet test

# Go
go test ./...

After test run: if any DeprecationWarning or deprecated-API log appears, treat as ERROR — fix before proceeding.

For Cypher: run each migrated query through EXPLAIN first:

# Via Query API v2
curl -X POST https://<host>/db/<database>/query/v2 \
  -u <user>:<password> -H "Content-Type: application/json" \
  -d '{"statement": "EXPLAIN <your query>"}'

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Common Migration Errors

Error	Cause	Fix
id(n) returns string, int comparison fails	elementId() returns string	Update stored IDs to string; fix WHERE clauses
Cannot merge node using null property value	MERGE key resolved to null	Validate params before MERGE
Neo4j.Driver.Exceptions.AuthenticationException	Wrong credential config after .NET rename	Update INeo4jLogger usage; verify config
TypeError: neo4j-driver is deprecated	Old package installed	Replace with neo4j>=6.0.0 in requirements
AttributeError: 'Session' has no 'read_transaction'	Python 5→6, method removed	Replace with execute_read()
RxSession not found	Java 6.x, Reactive API removed	Migrate to async or sync session
undefined is not a function (.readTransaction)	JS 6.x, method removed	Replace with executeRead()
Go: undefined: neo4j.Config	v5 import path still present	Update all imports to /v6/
PERIODIC COMMIT not supported	Cypher 25, clause removed	Use CALL (...) IN TRANSACTIONS
Unknown function id()	id() removed in Cypher 25	Replace with elementId()

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References

Load on demand — high discovery rate because explicitly linked:

• references/cypher-queries.md — version-branched Cypher changelog selection (4.x, 5.x, 2025.x)
• references/python-driver.md — Python changelog URLs, full version history
• references/javascript-driver.md — JS changelog URLs by version
• references/java-driver.md — Java changelog URLs by version
• references/dotnet-driver.md — .NET changelog URLs by version
• references/go-driver.md — Go migration guide with 5.0 and 6.0 sections

For any syntax not covered above, fetch: https://neo4j.com/docs/cypher-manual/25/deprecations-additions-removals-compatibility/

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Checklist

• Target Neo4j version confirmed; Cypher dialect selected (Cypher 5 or 25)
• Dependency files scanned; all driver versions identified
• Cypher substitution table applied to every query in codebase
• id(n) → elementId(n) and downstream int→string conversions fixed
• PERIODIC COMMIT → CALL IN TRANSACTIONS in all batch writes
• CALL { WITH x ... } → CALL (x) { ... } in all subqueries
• Package renames done (Python: neo4j-driver → neo4j)
• Deprecated session methods replaced (read_transaction/readTransaction → execute_read/executeRead)
• Resource cleanup added where missing (Python: context managers or .close())
• Bookmark API updated (last_bookmark → last_bookmarks, Bookmark → Bookmarks)
• Go imports updated from /v5/ to /v6/; neo4j.Config → config.Config
• Java: Java 21 confirmed; RxSession usages removed
• .NET: ILogger → INeo4jLogger; Neo4j.Driver.Signed → Neo4j.Driver
• Tests pass with no DeprecationWarnings
• EXPLAIN run on all migrated Cypher queries; no errors