kubo/docs/changelogs/v0.40.md

# Kubo changelog v0.40

<a href="https://ipshipyard.com/"><img align="right" src="https://github.com/user-attachments/assets/39ed3504-bb71-47f6-9bf8-cb9a1698f272" /></a>

This release was brought to you by the [Shipyard](https://ipshipyard.com/) team.

- [v0.40.0](#v0400)

## v0.40.0

- [Overview](#overview)
- [🔦 Highlights](#-highlights)
  - [🔢 UnixFS CID Profiles (IPIP-499)](#-unixfs-cid-profiles-ipip-499)
  - [🧹 Automatic cleanup of interrupted imports](#-automatic-cleanup-of-interrupted-imports)
  - [Routing V1 HTTP API now exposed by default](#routing-v1-http-api-now-exposed-by-default)
  - [Track total size when adding pins](#track-total-size-when-adding-pins)
  - [IPIP-523: `?format=` takes precedence over `Accept` header](#ipip-523-format-takes-precedence-over-accept-header)
  - [IPIP-524: Gateway codec conversion disabled by default](#ipip-524-gateway-codec-conversion-disabled-by-default)
  - [Improved IPNS over PubSub validation](#improved-ipns-over-pubsub-validation)
  - [New `ipfs diag datastore` commands](#new-ipfs-diag-datastore-commands)
  - [🔍 New `ipfs swarm addrs autonat` command](#-new-ipfs-swarm-addrs-autonat-command)
  - [🚇 Improved `ipfs p2p` tunnels with foreground mode](#-improved-ipfs-p2p-tunnels-with-foreground-mode)
  - [Improved `ipfs dag stat` output](#improved-ipfs-dag-stat-output)
  - [🔑 `ipfs key` improvements](#-ipfs-key-improvements)
  - [Accelerated DHT Client and Provide Sweep now work together](#accelerated-dht-client-and-provide-sweep-now-work-together)
  - [🌐 No unnecessary DNS lookups for AutoTLS addresses](#-no-unnecessary-dns-lookups-for-autotls-addresses)
  - [⏱️ Configurable gateway request duration limit](#️-configurable-gateway-request-duration-limit)
  - [🔧 Recovery from corrupted MFS root](#-recovery-from-corrupted-mfs-root)
  - [📡 RPC `Content-Type` headers for binary responses](#-rpc-content-type-headers-for-binary-responses)
  - [🔖 New `ipfs name get|put` commands](#-new-ipfs-name-getput-commands)
  - [📋 Long listing format for `ipfs ls`](#-long-listing-format-for-ipfs-ls)
  - [🖥️ WebUI Improvements](#-webui-improvements)
  - [📢 libp2p announces all interface addresses](#-libp2p-announces-all-interface-addresses)
  - [🗑️ Badger v1 datastore slated for removal this year](#-badger-v1-datastore-slated-for-removal-this-year)
  - [🐹 Go 1.26](#-go-126)
  - [📦️ Dependency updates](#-dependency-updates)
- [📝 Changelog](#-changelog)
- [👨‍👩‍👧‍👦 Contributors](#-contributors)

### Overview

### 🔦 Highlights

#### 🔢 UnixFS CID Profiles (IPIP-499)

[IPIP-499](https://github.com/ipfs/specs/pull/499) CID Profiles are presets that pin down how files get split into blocks and organized into directories. Useful when you need the same CID for the same data across different software or versions.

**New configuration [profiles](https://github.com/ipfs/kubo/blob/master/docs/config.md#profiles)**

- `unixfs-v1-2025`: modern CIDv1 profile with improved defaults
- `unixfs-v0-2015` (alias `legacy-cid-v0`): best-effort legacy CIDv0 behavior

Apply with: `ipfs config profile apply unixfs-v1-2025`

The `test-cid-v1` and `test-cid-v1-wide` profiles have been removed. Use `unixfs-v1-2025` or manually set specific `Import.*` settings instead.

**New [`Import.*`](https://github.com/ipfs/kubo/blob/master/docs/config.md#import) options**

- `Import.UnixFSHAMTDirectorySizeEstimation`: estimation mode (`links`, `block`, or `disabled`)
- `Import.UnixFSDAGLayout`: DAG layout (`balanced` or `trickle`)

**New [`ipfs add`](https://docs.ipfs.tech/reference/kubo/cli/#ipfs-add) CLI flags**

- `--dereference-symlinks` resolves all symlinks to their target content, replacing the deprecated `--dereference-args` which only resolved CLI argument symlinks
- `--empty-dirs` / `-E` controls inclusion of empty directories (default: true)
- `--hidden` / `-H` includes hidden files (default: false)
- `--trickle` implicit default can be adjusted via `Import.UnixFSDAGLayout`

**`ipfs files write` fix for CIDv1 directories**

When writing to MFS directories that use CIDv1 (via `--cid-version=1` or `ipfs files chcid`), single-block files now produce raw block CIDs (like `bafkrei...`), matching the behavior of `ipfs add --raw-leaves`. Previously, MFS would wrap single-block files in dag-pb even when raw leaves were enabled. CIDv0 directories continue to use dag-pb.

**Block size limit raised to 2MiB**

`ipfs block put`, `ipfs dag put`, and `ipfs dag import` now accept blocks up to 2MiB without `--allow-big-block`, matching the [bitswap spec](https://specs.ipfs.tech/bitswap-protocol/#block-sizes). The previous 1MiB limit was too restrictive and broke `ipfs dag import` of 1MiB-chunked non-raw-leaf data (protobuf wrapping pushes blocks slightly over 1MiB). The max `--chunker` value for `ipfs add` is `2MiB - 256 bytes` to leave room for protobuf framing. IPIP-499 profiles use lower chunk sizes (256KiB and 1MiB) and are not affected.

**HAMT Threshold Fix**

HAMT directory sharding threshold changed from `>=` to `>` to match the Go docs and JS implementation ([ipfs/boxo@6707376](https://github.com/ipfs/boxo/commit/6707376002a3d4ba64895749ce9be2e00d265ed5)). A directory exactly at 256 KiB now stays as a basic directory instead of converting to HAMT. This is a theoretical breaking change, but unlikely to impact real-world users as it requires a directory to be exactly at the threshold boundary. If you depend on the old behavior, adjust [`Import.UnixFSHAMTShardingSize`](https://github.com/ipfs/kubo/blob/master/docs/config.md#importunixfshamtshardingsize) to be 1 byte lower.

#### 🧹 Automatic cleanup of interrupted imports

If you cancel `ipfs add` or `ipfs dag import` mid-operation, Kubo now automatically cleans up incomplete data on the next daemon start. Previously, interrupted imports would leave orphan blocks in your repository that were difficult to identify and remove without pins and running explicit garbage collection.

Batch operations also use less memory now. Block data is written to disk immediately rather than held in RAM until the batch commits.

Under the hood, the block storage layer (flatfs) was rewritten to use atomic batch operations via a temporary staging directory. See [go-ds-flatfs#142](https://github.com/ipfs/go-ds-flatfs/pull/142) for details.

#### Routing V1 HTTP API now exposed by default

The [Routing V1 HTTP API](https://specs.ipfs.tech/routing/http-routing-v1/) is now exposed by default at `http://127.0.0.1:8080/routing/v1`. This allows light clients in browsers to use Kubo Gateway as a delegated routing backend instead of running a full DHT client. Support for [IPIP-476: Delegated Routing DHT Closest Peers API](https://github.com/ipfs/specs/pull/476) is included. Can be disabled via [`Gateway.ExposeRoutingAPI`](https://github.com/ipfs/kubo/blob/master/docs/config.md#gatewayexposeroutingapi).

#### Track total size when adding pins

Adds total size progress tracking of pinned nodes during `ipfs pin add --progress`. The output now shows the total size of the pinned dag.

Example output:

```
Fetched/Processed 336 nodes (83 MB)
```

#### IPIP-523: `?format=` takes precedence over `Accept` header

[IPIP-523](https://github.com/ipfs/specs/pull/523) simplifies HTTP content negotiation by making the `?format=` URL query parameter always take priority over the `Accept` HTTP header when both are present.

This ensures deterministic HTTP caching behavior and protects against CDNs that commingle different response types under the same cache key. It also allows browsers to use `?format=` reliably even when they send `Accept` headers with specific content types.

The only breaking change is for edge cases where a client sends both a specific `Accept` header and a different `?format=` value for an explicitly supported format (`tar`, `raw`, `car`, `dag-json`, `dag-cbor`, etc.). Previously `Accept` would win. Now `?format=` always wins.

#### IPIP-524: Gateway codec conversion disabled by default

Codec conversion is now disabled by default per [IPIP-524](https://github.com/ipfs/specs/pull/524).
Requests for a format that differs from the block's codec will return `406 Not Acceptable`.

**Migration**: Clients should fetch raw blocks (`?format=raw` or `Accept: application/vnd.ipld.raw`)
and convert client-side using libraries like [@helia/verified-fetch](https://www.npmjs.com/package/@helia/verified-fetch).

This change removes gateways from a gatekeeping role: new codecs can now be adopted by clients
immediately without waiting for gateway operator updates. Set [`Gateway.AllowCodecConversion`](https://github.com/ipfs/kubo/blob/master/docs/config.md#gatewayallowcodecconversion)
to `true` to restore previous behavior.

#### Improved IPNS over PubSub validation

[IPNS over PubSub](https://specs.ipfs.tech/ipns/ipns-pubsub-router/) implementation in Kubo is now more reliable. Duplicate messages are rejected even in large networks where messages may cycle back after the in-memory cache expires.

Kubo now persists the maximum seen sequence number per peer to the datastore ([go-libp2p-pubsub#BasicSeqnoValidator](https://pkg.go.dev/github.com/libp2p/go-libp2p-pubsub#BasicSeqnoValidator)), providing stronger duplicate detection that survives node restarts. This addresses message flooding issues reported in [#9665](https://github.com/ipfs/kubo/issues/9665).

Kubo's pubsub is optimized for IPNS use case. For custom pubsub applications requiring different validation logic, use [go-libp2p-pubsub](https://github.com/libp2p/go-libp2p-pubsub) directly in a dedicated binary.

#### New `ipfs diag datastore` commands

New experimental commands for low-level datastore inspection:

- `ipfs diag datastore get <key>` - Read raw value at a datastore key (use `--hex` for hex dump)
- `ipfs diag datastore count <prefix>` - Count entries matching a datastore prefix

The daemon must not be running when using these commands. Run `ipfs diag datastore --help` for usage examples.

#### 🔍 New `ipfs swarm addrs autonat` command

The new `ipfs swarm addrs autonat` command shows the network reachability status of your node's addresses as verified by AutoNAT V2. AutoNAT V2 leverages other nodes in the IPFS network to test your node's external public reachability, providing a self-service way to debug connectivity.

Public reachability is important for:

- **Direct data fetching**: Other nodes can fetch data directly from your node without NAT hole punching.
- **Browser access**: Web browsers can connect to your node directly for content retrieval.
- **DHT participation**: Your node can act as a DHT server, helping to maintain the distributed hash table and making content routing more robust.

The command displays:

- Overall reachability status (public, private, or unknown)
- Per-address reachability showing which specific addresses are reachable, unreachable, or unknown

Example output:
```
AutoNAT V2 Status:
  Reachability: public

Per-Address Reachability:
  Reachable:
    /ip4/203.0.113.42/tcp/4001
    /ip4/203.0.113.42/udp/4001/quic-v1
  Unreachable:
    /ip6/2001:db8::1/tcp/4001
  Unknown:
    /ip4/203.0.113.42/udp/4001/webrtc-direct
```

This helps diagnose connectivity issues and understand if your node is publicly reachable. See the [AutoNAT V2 spec](https://github.com/libp2p/specs/blob/master/autonat/autonat-v2.md) for more details.

#### 🚇 Improved `ipfs p2p` tunnels with foreground mode

P2P tunnels can now run like SSH port forwarding: start a tunnel, use it, and it cleans up automatically when you're done.

The new `--foreground` (`-f`) flag for `ipfs p2p listen` and `ipfs p2p forward` keeps the command running until interrupted. When you Ctrl+C, send SIGTERM, or stop the service, the tunnel is removed automatically:

```console
$ ipfs p2p listen /x/ssh /ip4/127.0.0.1/tcp/22 --foreground
Listening on /x/ssh, forwarding to /ip4/127.0.0.1/tcp/22, waiting for interrupt...
^C
Received interrupt, removing listener for /x/ssh
```

Without `--foreground`, commands return immediately and tunnels persist until explicitly closed (existing behavior).

See [docs/p2p-tunnels.md](https://github.com/ipfs/kubo/blob/master/docs/p2p-tunnels.md) for usage examples.

#### Improved `ipfs dag stat` output

The `ipfs dag stat` command has been improved for better terminal UX:

- Progress output now uses a single line with carriage return, avoiding terminal flooding
- Progress is auto-detected: shown only in interactive terminals by default
- Human-readable sizes are now displayed alongside raw byte counts

Example progress (interactive terminal):
```
Fetched/Processed 84 blocks, 2097152 bytes (2.1 MB)
```

Example summary output:
```
Summary
Total Size: 2097152 (2.1 MB)
Unique Blocks: 42
Shared Size: 1048576 (1.0 MB)
Ratio: 1.500000
```

Use `--progress=true` to force progress even when piped, or `--progress=false` to disable it.

#### 🔑 `ipfs key` improvements

`ipfs key ls` is now the canonical command for listing keys, matching `ipfs pin ls` and `ipfs files ls`. The old `ipfs key list` still works but is deprecated.

Listing also became more resilient: bad keys are now skipped with an error log instead of failing the entire operation.

#### Accelerated DHT Client and Provide Sweep now work together

Previously, provide operations could start before the Accelerated DHT Client discovered enough peers, causing sweep mode to lose its efficiency benefits. Now, providing waits for the initial network crawl (about 10 minutes). Your content will be properly distributed across DHT regions after initial DHT map is created. Check `ipfs provide stat` to see when providing begins.

#### 🌐 No unnecessary DNS lookups for AutoTLS addresses

Kubo no longer makes DNS queries for [AutoTLS](https://web.archive.org/web/20260112031855/https://blog.libp2p.io/autotls/) addresses like `1-2-3-4.peerid.libp2p.direct`. Since the IP is encoded in the hostname (`1-2-3-4` means `1.2.3.4`), Kubo extracts it locally. This reduces load on the public good DNS servers at `libp2p.direct` run by [Shipyard](https://ipshipyard.com), reserving them for web browsers which lack direct DNS access and must rely on the browser's resolver.

To disable, set [`AutoTLS.SkipDNSLookup`](https://github.com/ipfs/kubo/blob/master/docs/config.md#autotlsskipdnslookup) to `false`.

#### ⏱️ Configurable gateway request duration limit

[`Gateway.MaxRequestDuration`](https://github.com/ipfs/kubo/blob/master/docs/config.md#gatewaymaxrequestduration) sets an absolute deadline for gateway requests. Unlike `RetrievalTimeout` (which resets on each data write and catches stalled transfers), this is a hard limit on the total time a request can take.

The default 1 hour limit (previously hardcoded) can now be adjusted to fit your deployment needs. This is a fallback that prevents requests from hanging indefinitely when subsystem timeouts are misconfigured or fail to trigger. Returns 504 Gateway Timeout when exceeded.

#### 🔧 Recovery from corrupted MFS root

If your daemon fails to start because the MFS root is not a directory (due to misconfiguration, operational error, or disk corruption), you can now recover without deleting and recreating your repository in a new `IPFS_PATH`.

The new `ipfs files chroot` command lets you reset the MFS (Mutable File System) root or restore it to a known valid CID:

```console
# Reset MFS to an empty directory
$ ipfs files chroot --confirm

# Or restore from a previously saved directory CID
$ ipfs files chroot --confirm QmYourBackupCID
```

See `ipfs files chroot --help` for details.

#### 📡 RPC `Content-Type` headers for binary responses

HTTP RPC endpoints that return binary data now set appropriate `Content-Type` headers, making it easier to integrate with HTTP clients and tooling that rely on MIME types. On CLI these commands behave the same as before, but over HTTP RPC you now get proper headers:

| Endpoint               | Content-Type                              |
|------------------------|-------------------------------------------|
| `/api/v0/get`          | `application/x-tar` or `application/gzip` |
| `/api/v0/dag/export`   | `application/vnd.ipld.car`                |
| `/api/v0/block/get`    | `application/vnd.ipld.raw`                |
| `/api/v0/name/get`     | `application/vnd.ipfs.ipns-record`        |
| `/api/v0/diag/profile` | `application/zip`                         |

#### 🔖 New `ipfs name get|put` commands

You can now backup, restore, and share IPNS records without needing the private key.

```console
$ ipfs name get /ipns/k51... > record.bin
$ ipfs name get /ipns/k51... | ipfs name inspect
$ ipfs name put k51... record.bin
```

These are low-level tools primarily for debugging and testing IPNS.

The `put` command validates records by default. Use `--force` to skip validation and test how routing systems handle malformed or outdated records. Note that `--force` only bypasses this command's checks; the routing system may still reject invalid records.

#### 📋 Long listing format for `ipfs ls`

The `ipfs ls` command now supports `--long` (`-l`) flag for displaying Unix-style file permissions and modification times. This works with files added using `--preserve-mode` and `--preserve-mtime`. See `ipfs ls --help` for format details and examples.

#### 🖥️ WebUI Improvements

IPFS Web UI has been updated to [v4.11.0](https://github.com/ipfs/ipfs-webui/releases/tag/v4.11.0).

##### Search and filter files

You can now search and filter files directly in the Files screen. Type a name, CID, or file extension and the list narrows down in real time. Works in both list and grid view.

> ![Search and filter files](https://github.com/user-attachments/assets/cc266dbc-8424-4a8a-a6b7-a80a5a25683b)

##### DHT Provide diagnostic screen

New screen under Diagnostics that shows the health of DHT Provide operations. You can see reprovide cycle progress, worker utilization, queue status, and network throughput at a glance, without having to use the [`ipfs provide stat`](https://docs.ipfs.tech/reference/kubo/cli/#ipfs-provide-stat) CLI.

> ![DHT Provide diagnostic screen](https://github.com/user-attachments/assets/c577309a-2249-46f8-87d9-f0da42955f32)

##### Better path handling in Files

The Inspect button now resolves `/ipfs/` and `/ipns/` paths to their final CID before opening the IPLD Explorer. The Explore form also accepts `ipfs://` and `ipns://` protocol URLs. Previously, these would show a blank screen or an infinite spinner. Path resolution errors now also show better error pages:

> ![Better path handling in Files](https://github.com/user-attachments/assets/3494835b-0b93-4990-9971-078273671928)

#### 📢 libp2p announces all interface addresses

go-libp2p [v0.47.0](https://github.com/libp2p/go-libp2p/releases/tag/v0.47.0) includes a rewritten routing library ([`go-netroute`](https://github.com/libp2p/go-netroute/pull/64)) that fixes interop with VPN and WireGuard/Tailscale setups. A side effect: when listening on `0.0.0.0`, libp2p now returns addresses from all network interfaces instead of just the primary one ([go-libp2p#3460](https://github.com/libp2p/go-libp2p/issues/3460)).

This means easier connectivity and less manual configuration for most desktop, VPN, and self-hosted users. However, if you don't run with the [`server` profile](https://github.com/ipfs/kubo/blob/master/docs/config.md#server-profile) and have an empty [`Addresses.NoAnnounce`](https://github.com/ipfs/kubo/blob/master/docs/config.md#addressesnoannounce), your node may now announce internal addresses (e.g. Docker bridge `172.17.0.0/16` or Tailscale `100.64.0.0/10`) to the DHT. In the default setup, AutoNAT will probe and mark unreachable ones as offline and they won't be listed, but you can also filter them out explicitly.

To check what your node announces and filter out unwanted ranges:

```console
$ ipfs swarm addrs local
$ ipfs config --json Addresses.NoAnnounce '["/ip4/172.17.0.0/ipcidr/16"]'
```

The [`server` profile](https://github.com/ipfs/kubo/blob/master/docs/config.md#server-profile) already [filters common private ranges](https://github.com/ipfs/kubo/blob/master/config/profile.go#L24-L43) via `Addresses.NoAnnounce`.

#### 🗑️ Badger v1 datastore slated for removal this year

The `badgerds` datastore (based on badger 1.x) is slated for removal. Badger v1 has not been maintained by its upstream maintainers for years and has known bugs including startup timeouts, shutdown hangs, and file descriptor exhaustion. Starting with this release, every daemon start with a badger-based repository prints a loud deprecation error on stderr.

See the [`badgerds` profile documentation](https://github.com/ipfs/kubo/blob/master/docs/config.md#badgerds-profile) for migration guidance, and [#11186](https://github.com/ipfs/kubo/issues/11186) for background.

#### 🐹 Go 1.26

This release is built with [Go 1.26](https://go.dev/doc/go1.26).

You should see lower memory usage and reduced GC pauses thanks to the new Green Tea garbage collector (10-40% less GC overhead). Reading block data and API responses is faster due to `io.ReadAll` improvements (~2x faster, ~50% less memory). On 64-bit platforms, heap base address randomization adds a layer of security hardening.

#### 📦️ Dependency updates

- update `go-libp2p` to [v0.47.0](https://github.com/libp2p/go-libp2p/releases/tag/v0.47.0) (incl. [v0.46.0](https://github.com/libp2p/go-libp2p/releases/tag/v0.46.0))
  - Reduced WebRTC log noise by using debug level for pion errors ([go-libp2p#3426](https://github.com/libp2p/go-libp2p/pull/3426)).
  - Fixed mDNS discovery on Windows and macOS by filtering addresses to reduce packet size ([go-libp2p#3434](https://github.com/libp2p/go-libp2p/pull/3434)).
  - AutoTLS addresses no longer get marked unreachable when peers lack WebSockets support. Swarm heals over time ([go-libp2p#3435](https://github.com/libp2p/go-libp2p/pull/3435)).
  - Fixed `stream.Close()` blocking indefinitely on unresponsive peers ([go-libp2p#3448](https://github.com/libp2p/go-libp2p/pull/3448)).
- update `quic-go` to [v0.59.0](https://github.com/quic-go/quic-go/releases/tag/v0.59.0) (incl. [v0.58.0](https://github.com/quic-go/quic-go/releases/tag/v0.58.0) + [v0.57.0](https://github.com/quic-go/quic-go/releases/tag/v0.57.0))
- update `p2p-forge` to [v0.7.0](https://github.com/ipshipyard/p2p-forge/releases/tag/v0.7.0)
- update `go-ds-pebble` to [v0.5.9](https://github.com/ipfs/go-ds-pebble/releases/tag/v0.5.9)
  - updates `github.com/cockroachdb/pebble` to [v2.1.4](https://github.com/cockroachdb/pebble/releases/tag/v2.1.4) to enable Go 1.26 support
- update `go-libp2p-pubsub` to [v0.15.0](https://github.com/libp2p/go-libp2p-pubsub/releases/tag/v0.15.0)
- update `go-ipld-prime` to [v0.22.0](https://github.com/ipld/go-ipld-prime/releases/tag/v0.22.0)
- update `boxo` to [v0.37.0](https://github.com/ipfs/boxo/releases/tag/v0.37.0) (incl. [v0.36.0](https://github.com/ipfs/boxo/releases/tag/v0.36.0))
- update `go-libp2p-kad-dht` to [v0.38.0](https://github.com/libp2p/go-libp2p-kad-dht/releases/tag/v0.38.0) (includes [v0.37.1](https://github.com/libp2p/go-libp2p-kad-dht/releases/tag/v0.37.1), [v0.37.0](https://github.com/libp2p/go-libp2p-kad-dht/releases/tag/v0.37.0))
- update `ipfs-webui` to [v4.11.1](https://github.com/ipfs/ipfs-webui/releases/tag/v4.11.1) (incl. [v4.11.0](https://github.com/ipfs/ipfs-webui/releases/tag/v4.11.0))
- update `gateway-conformance` tests to [v0.10](https://github.com/ipfs/gateway-conformance/releases/tag/v0.10.0) (incl. [v0.9](https://github.com/ipfs/gateway-conformance/releases/tag/v0.9.0))

### 📝 Changelog

### 👨‍👩‍👧‍👦 Contributors