## Problem
Coderd can expose an MCP server at `/api/experimental/mcp/http` (we have
this enabled on dogfood). Its workspace tools dialed agents through a
per-call client-side tailnet stack. Every tool call re-created a
WireGuard device, netstack, magicsock + UDP sockets, DERP connection,
coordinator websocket, and their goroutines — in a process that already
runs a long-lived shared tailnet. The duplicate stacks drove up resource
usage under load.
## Fix
Route this server's tool calls through the existing shared tailnet, so
none of those transports are reconstructed per call. Closing an
`AgentConn` now releases a tunnel reference instead of tearing down a
transport.
## Potential follow-up
`coder exp mcp server` still builds a fresh tailnet per call. It pays
per-call latency and causes coordinator/DERP churn. A shared CLI tailnet
is more involved — unlike coderd, the CLI has no existing shared tailnet
to reuse, so it would need a new long-lived client-side tailnet with
reconnect, sleep/wake, and idle-destination handling. There's less
motivation to optimize this, given the client-side MCP does not compete
for resources with coderd.
Closes CODAGT-199
> Generated by mux, but reviewed by a human
Fixes three classes of edit_files bugs and adds structured per-file
diff output for tool callers:
- New IncludeDiff flag on FileEditRequest; when set, the agent
returns FileEditResponse.Files[]{Path, Diff} with unified diffs
computed via go-udiff v0.4.1 Lines + ToUnified (not Unified,
which calls log.Fatalf on internal error).
- Fuzzy match comparators split each line into leading whitespace,
body, trailing whitespace, and ending. The splice substitutes at
each position: on agreement between search and replace the file's
bytes win; on disagreement the replacement's bytes are spliced
verbatim. Carve-outs for empty-body lines, multi-line EOF splices,
and level-aware indent translation for inserted lines.
- Indent-unit detection (GCD for spaces, tab-priority) lets a 4sp
LLM search insert correctly into tab or 2sp files. Falls back to
the previous cLead-inheritance path when units can't be detected
cleanly.
- Empty search is rejected with "search string must not be empty".
- Duplicate file paths in one request are rejected; symlink aliases
resolved via api.resolvePath before the dedup check.
- Frontend EditFilesRenderer consumes the structured files array by
explicit path (no label munging) with per-file synthetic fallback
for older agents or mismatched paths. On error, no diff is
rendered so the synthetic fallback doesn't misrepresent a
rejected edit as applied.
Breaking change: AgentConn.EditFiles changes from (ctx, req) error
to (ctx, req) (FileEditResponse, error) in codersdk/workspacesdk.
Source-breaking for external Go consumers; no compat shim per plan
owner.
Out of scope (tracked in CODAGT-214): level-aware indent for
middle-substituted splice lines. Locked in
TestEditFiles_FuzzyIndent_InsertionLevelAware's Lock_* cases plus
TestEditFiles_ReplaceAll_FuzzyIndentGap.
> This PR was authored by Mux on behalf of Mike.
## Summary
- add persistent plan mode for chats and the chat-specific plan file
flow
- add structured planning tools such as `ask_user_question` and
`propose_plan`
- keep `write_file` and `edit_files` constrained to the chat-specific
plan file during plan turns
- allow shell exploration in plan mode, including subagents, via
`execute` and `process_output`
- block implementation-oriented, provider-native, MCP, dynamic, and
computer-use tools during plan turns
- update the chat UI, tests, and docs for the new planning flow
The agents chat interface displays thumbnails for videos recorded by the
computer use agent. Currently, to display a thumbnail, the frontend
downloads the entire video and shows the first frame. This PR starts
storing a new thumbnail file in the database for every recorded video,
and exposes the file id in the `wait_agent` tool result alongside the
recording file id, so the frontend can fetch just the thumbnail.
Piggybacks on #23878. Moves instruction file reading and skill discovery
from `chatd` (server-side, via multiple `LS`/`ReadFile` round-trips
through the agent connection) to the agent itself (local filesystem
access).
This intentionally drops backward compatibility with older agents that
don't support the context-config endpoint. Agents and server are
deployed together; there is no rolling-update contract to maintain here.
## What changed
The agent's `GET /api/v0/context-config` response now returns
`[]ChatMessagePart` directly — the same types chatd persists. This
eliminates intermediate type conversions and makes the protocol
extensible.
| Field | Type | Description |
|---|---|---|
| `parts` | `[]ChatMessagePart` | Context-file and skill parts, ready to
persist |
| `working_dir` | `string` | Agent's resolved working directory |
Removed from the response: `instructions_dirs`, `instructions_file`,
`skills_dirs`, `skill_meta_file`, `mcp_config_files` — the agent reads
files locally and returns their content as parts.
Removed from chatd: all legacy `LS`/`ReadFile` fallback code
(`readHomeInstructionFile`, `readInstructionDirFile`, `DiscoverSkills`
via LS, etc).
## Why
The previous architecture had the agent resolve paths, serve them over
HTTP, then `chatd` make N+1 round-trips back through the agent
connection to read files. The agent has direct filesystem access and
should just read the files.
## Key design decisions
- **Agent returns `ChatMessagePart` directly** — same types chatd
persists. No intermediate `InstructionFileEntry`/`SkillEntry` types
needed.
- **`SkillMeta.MetaFile`** — persisted via `ContextFileSkillMetaFile` on
the skill part, so custom meta file names
(`CODER_AGENT_EXP_SKILL_META_FILE`) survive across chat turns.
- **No pre-read body** — `read_skill` always dials the workspace to
fetch the skill body on demand. Simpler than caching the body in the
response.
- **MCP config paths kept agent-internal** — `MCPConfigFiles()` getter,
not sent over the wire.
- **No backward compat fallback** — old agents that don't support
context-config get no instruction files. This is acceptable since agent
and server deploy together.
This PR introduces screen recording of the computer use agent using the
virtual desktop.
- Screen recording is triggered by a `wait_agent` tool call. Recording
is stopped by a successful `wait_agent` tool call or when there hasn't
been any desktop activity for 10 minutes.
- Recordings are handled by the `portabledesktop` cli via the `record`
command. The videos are sped up in periods of inactivity.
- Recordings are saved to the database to the `chat_files` table.
There's a hard limit of 100MB per recording. Larger recordings are
dropped.
- A successful `wait_agent` on a computer use subagent tool call returns
a `recording_file_id`, later allowing the frontend to display the
corresponding video.
Replace hardcoded paths for instruction files, skills, and MCP config
with
values read from `CODER_AGENT_EXP_*` environment variables. Template
authors
configure paths via the existing `coder_agent` `env` block. The agent
resolves `~`, relative, and absolute paths locally, then serves the
resolved config over `GET /api/v0/context-config`. `chatd` fetches this
once per workspace attach and falls back to today's defaults for older
agents.
All path env vars are comma-separated, allowing multiple directories:
| Env Var | Default | Controls |
|---|---|---|
| `CODER_AGENT_EXP_INSTRUCTIONS_DIRS` | `~/.coder` | Dirs containing the
instruction file |
| `CODER_AGENT_EXP_INSTRUCTIONS_FILE` | `AGENTS.md` | Instruction file
name |
| `CODER_AGENT_EXP_SKILLS_DIRS` | `.agents/skills` | Skills directories
|
| `CODER_AGENT_EXP_SKILL_META_FILE` | `SKILL.md` | Skill metadata file
name |
| `CODER_AGENT_EXP_MCP_CONFIG_FILES` | `.mcp.json` | MCP config files |
### Example
```hcl
resource "coder_agent" "main" {
os = "linux"
arch = "amd64"
env = {
CODER_AGENT_EXP_INSTRUCTIONS_DIRS = "/opt/company/agent-config,~/.coder"
CODER_AGENT_EXP_INSTRUCTIONS_FILE = "CLAUDE.md"
CODER_AGENT_EXP_SKILLS_DIRS = "/opt/company/ai-skills,.agents/skills"
CODER_AGENT_EXP_MCP_CONFIG_FILES = "/opt/company/mcp.json,.mcp.json"
}
}
```
<details>
<summary>Implementation Details</summary>
### Architecture
Follows the same pattern as MCP tool discovery:
agent resolves locally → exposes via HTTP → chatd consumes.
**Agent-side** (`agent/agentcontextconfig/`):
- `ResolvePath` / `ResolvePaths` handle `~`, relative, and absolute path
forms; returns `""` for relative paths when baseDir is empty
- `Config` reads env vars, falls back to defaults, resolves all paths
- `GET /api/v0/context-config` serves the resolved config as JSON
**chatd-side** (`coderd/x/chatd/`):
- Calls `conn.ContextConfig()` once on first workspace attach
- Falls back to hardcoded defaults on 404 (older agents)
- Iterates instruction dirs, skills dirs using resolved absolute paths
- `LSRelativityRoot` everywhere — no more home/root juggling
### Key design decisions
- **`EXP_` prefix**: env vars use `CODER_AGENT_EXP_*` to indicate
experimental status
- **Plural names**: comma-separated vars use plural names (`DIRS`,
`FILES`); single-value vars use singular (`FILE`)
- **Defaults in `workspacesdk`**: default constants live in
`codersdk/workspacesdk/` so both agent and server reference them without
cross-layer imports
- **`skillMetaFile` persistence**: stored on context-file parts via
`ContextFileSkillMetaFile` and restored on subsequent chat turns so
custom values survive across turns
- **Working dir dedup**: `slices.Contains` guard prevents reading the
same instruction file from both `InstructionsDirs` and the working
directory
- **MCP server dedup**: first-occurrence-wins dedup prevents leaking
duplicate connections from overlapping config files
- **ResolvePath safety**: returns `""` for relative paths when `baseDir`
is empty, so `ResolvePaths` filters them out
### Files changed
| File | Change |
|---|---|
| `agent/agentcontextconfig/` | New package — path resolution + HTTP
endpoint |
| `codersdk/workspacesdk/agentconn.go` | `ContextConfigResponse` type,
default constants, client method |
| `agent/agent.go` + `agent/api.go` | Wire up endpoint, pass config to
MCP |
| `agent/x/agentmcp/manager.go` | Accept `[]string` MCP config paths,
dedup by name |
| `coderd/x/chatd/chatd.go` | Fetch config, thread through, named
returns |
| `coderd/x/chatd/instruction.go` | Accept configurable dir + file name,
`skillMetaFileFromParts` |
| `coderd/x/chatd/chattool/skill.go` | Accept configurable dirs + meta
file |
| `codersdk/chats.go` | `ContextFileSkillMetaFile` field for persistence
|
### Test coverage
- `TestConfig` (4 cases): defaults, custom env vars, whitespace
trimming, comma-separated dirs
- `TestResolvePath` / `TestResolvePaths`: including empty baseDir edge
case
- `TestPersistInstructionFilesFallbackOnOlderAgent`: backward-compat
path when `ContextConfig` returns 404
- `TestChatMessagePartVariantTags`: updated exclusion list for new
internal field
### Backward compatibility
Older agents return 404 for the new endpoint. `chatd` catches this and
falls back to today's defaults via `readHomeInstructionFile` (using
`LSRelativityHome`). Existing workspaces work with no changes.
</details>
Coder's chat (chatd) can now discover and use MCP servers configured in
a workspace's `.mcp.json` file. This brings project-specific tooling
(GitHub, databases, docs servers, etc.) into the chat without any manual
configuration.
## How it works
The workspace agent reads `.mcp.json` from the workspace directory (same
format Claude Code uses), connects to the declared MCP servers —
spawning child processes for stdio servers and connecting over the
network for HTTP/SSE — and caches their tool lists. Two new agent HTTP
endpoints expose this:
- `GET /api/v0/mcp/tools` returns the cached tool list (supports
`?refresh=true`)
- `POST /api/v0/mcp/call-tool` proxies calls to the correct server
On each chat turn, chatd calls `ListMCPTools` through the existing
`AgentConn` tailnet connection, wraps each tool as a
`fantasy.AgentTool`, and adds them to the LLM's tool set alongside
built-in and admin-configured MCP tools. Tool names are prefixed with
the server name (`github__create_issue`) to avoid collisions.
Failed server connections are logged and skipped — they never block the
agent or break the chat. Child stdio processes are terminated on agent
shutdown.
This PR changes agents desktop resolution from 1366x768 to 1920x1080.
Anthropic requires the that the resolution of desktop screenshots fits
in 1,150,000 total pixels, so we downscale screenshots to 1280x720
before sending them to the LLM provider.
Resolution scaling was already implemented, but our code didn't exercise
it. The resolution bump showed that there were some bugs in the scaling
logic - this PR fixes these bugs too.
Replace the 200ms polling loop in chatd's execute and
process_output tools with server-side blocking via sync.Cond
on HeadTailBuffer.
The agent's GET /{id}/output endpoint accepts ?wait=true to
block until the process exits or a 5-minute server cap expires.
The process_output tool blocks by default for 10s (overridable
via wait_timeout), and falls back to a non-blocking snapshot on
timeout. The execute tool's foreground path makes a single
blocking call instead of polling.
Related #23316
## Problem
The `edit_files` tool used `strings.ReplaceAll` for exact substring
matches, silently replacing **every** occurrence. When an LLM's search
string wasn't unique in the file, this caused unintended edits. Fuzzy
matches (passes 2 and 3) only replaced the first occurrence, creating
inconsistent behavior. Zero matches were also silently ignored.
## Investigation
Investigated how **coder/mux** and **openai/codex** handle this:
| Tool | Multiple matches | No match | Flag |
|---|---|---|---|
| **coder/mux** `file_edit_replace_string` | Error (default
`replace_count=1`) | Error | `replace_count` (int, default 1, -1=all) |
| **openai/codex** `apply_patch` | Uses first match after cursor
(structural disambiguation via context lines + `@@` markers) | Error |
None (different paradigm) |
| **coder/coder** `edit_files` (before) | Exact: replaces all. Fuzzy:
replaces first. | Silent success | None |
## Solution
Adopted the mux approach (error on ambiguity) with a simpler
`replace_all: bool` instead of `replace_count: int`:
- **Default (`replace_all: false`)**: search string must match exactly
once. Multiple matches → error with guidance: *"search string matches N
occurrences. Include more surrounding context to make the match unique,
or set replace_all to true"*
- **`replace_all: true`**: replaces all occurrences (opt-in for
intentional bulk operations like variable renames)
- **Zero matches**: now returns an error instead of silently succeeding
Chose `bool` over `int` count because:
1. LLMs are bad at counting occurrences
2. The real intent is binary (one specific spot vs. all occurrences)
3. Simpler error recovery loop for the LLM
## Changes
| File | Change |
|---|---|
| `codersdk/workspacesdk/agentconn.go` | Add `ReplaceAll bool` to
`FileEdit` struct |
| `agent/agentfiles/files.go` | Count matches before replacing; error if
>1 and not opted in; error on zero matches; add `countLineMatches`
helper |
| `codersdk/toolsdk/toolsdk.go` | Expose `replace_all` in tool schema
with description |
| `agent/agentfiles/files_test.go` | Update existing tests, add
`EditEditAmbiguous`, `EditEditReplaceAll`, `NoMatchErrors`,
`AmbiguousExactMatch`, `ReplaceAllExact` |
Implement the backend for the desktop feature for agents.
- Adds a new `/api/experimental/chats/$id/desktop` endpoint to coderd
which exposes a VNC stream from a
[portabledesktop](https://github.com/coder/portabledesktop) process
running inside the workspace
- Adds a new `spawn_computer_use_agent` tool to chatd, which spawns a
subagent that has access to the `computer` tool which lets it interact
with the `portabledesktop` process running inside the workspace
- Adds the plumbing to make the above possible
There's a follow up frontend PR here:
https://github.com/coder/coder/pull/23006
Adds real-time git status watching for workspace agents, so the frontend
can subscribe over WebSocket and show
git file changes in near real-time.
1. Subscription is scoped to a **chat** via `GET
/api/experimental/chats/{chat}/git/watch`.
2. The workspace agent automatically determines which paths to watch
based on tool calls made by the chat (and its ancestor chats).
3. Workspace agent polls subscribed repo working trees on a 30s
interval, on tools calls, and on explicit `refresh` from the client.
4. Scans are rate-limited to at most once per second.
5. Edited paths are tracked **in-memory** inside the workspace agent.
There is no database persistence — state is lost on agent restart. This
will be addresses in a future PR.
6. Messages sent over WebSocket include a full-repo snapshot (unified
diff, branch, origin). A new message is emitted only when the snapshot
changes.
This PR was implemented with AI with me closely controlling what it's
doing. The code follows a plan file that was updated continuously during
implementation. Here's the file if you'd like to see it:
[project.md](https://gist.github.com/hugodutka/8722cf80c92f8a56555f7bc595b770e2).
It reflects the current state of the PR.
## Summary
Adds a new agent-side process management HTTP API and rewrites the chat
execute tool to use it instead of SSH sessions.
## What changed
### New agent/agentproc/ package
- **headtail.go** — Thread-safe io.Writer with bounded memory (16KB head
+ 16KB tail ring buffer). Provides LLM-ready output with truncation
metadata and long-line truncation at 2048 bytes.
- **headtail_test.go** — 16 tests including race detector coverage for
concurrent writes.
- **process.go** — Manager + Process types for lifecycle management
using agentexec.Execer for proper OOM/nice scores.
- **api.go** — HTTP API following the agentfiles chi router pattern. 4
endpoints: start, list, output, signal.
### Agent wiring (agent/agent.go, agent/api.go)
Mounts the process API at /api/v0/processes, mirroring how agentfiles is
mounted.
### SDK (codersdk/workspacesdk/agentconn.go)
4 new AgentConn interface methods + 7 request/response types:
- StartProcess, ListProcesses, ProcessOutput, SignalProcess
### Execute tool rewrite (coderd/chatd/chattool/execute.go)
- SSH to Agent API: conn.StartProcess() + conn.ProcessOutput() polling
- New parameters: workdir, run_in_background
- Structured response: success, exit_code, wall_duration_ms, error,
truncated, note, background_process_id
- Non-interactive env vars: GIT_EDITOR=true, TERM=dumb, NO_COLOR=1,
PAGER=cat, etc.
- Output truncation: HeadTailBuffer caps at 32KB for LLM consumption
- File-dump detection with advisory notes suggesting read_file
- Default timeout: 60s to 10s
- Foreground polling: 200ms intervals until exit or timeout
## Architecture
State lives on the agent, surviving coderd failover and instance
changes. Any coderd replica can query any agent via HTTP over tailnet.
## Summary
Adds a new line-based file reading endpoint to the workspace agent,
replacing the unbounded byte-based approach for the `read_file` chat
tool and `coder_workspace_read_file` MCP tool.
**Problem**: The current `read_file` tool returns the entire file
contents with no limits, which can blow up LLM context windows and cause
OOM issues with large files.
**Solution**: Inspired by [`coder/mux`](https://github.com/coder/mux)
and [`openai/codex`](https://github.com/openai/codex), implement a
line-based reader with safety limits.
## Changes
### Agent (`agent/agentfiles/`)
- New `/read-file-lines` endpoint with `HandleReadFileLines` handler
- Line-based `offset` (1-based line number, default: 1) and `limit`
(line count, default: 2000)
- Safety constants:
| Constant | Value | Purpose |
|---|---|---|
| `MaxFileSize` | 1 MB | Reject files larger than this at stat |
| `MaxLineBytes` | 1,024 | Per-line truncation with `... [truncated]`
marker |
| `MaxResponseLines` | 2,000 | Max lines per response |
| `MaxResponseBytes` | 32 KB | Max total response size |
| `DefaultLineLimit` | 2,000 | Default when no limit specified |
- Line numbering format: `1\tcontent` (tab-separated)
- Structured JSON response: `{ success, file_size, total_lines,
lines_read, content, error }`
- Hard errors when limits exceeded — tells the LLM to use
`offset`/`limit`
- Existing byte-based `/read-file` endpoint preserved (used by
`instruction.go`)
### SDK (`codersdk/workspacesdk/`)
- `ReadFileLinesResponse` type added
- `ReadFileLines` method added to `AgentConn` interface
- Mock regenerated
### Chat tool (`coderd/chatd/chattool/`)
- `read_file` tool now uses `conn.ReadFileLines()` instead of
`conn.ReadFile()`
- Updated tool description to document line-based parameters
- Response includes `file_size`, `total_lines`, `lines_read` metadata
### MCP tool (`codersdk/toolsdk/`)
- `coder_workspace_read_file` updated to use line-based reading
- Schema descriptions updated for line-based offset/limit
- Removed `maxFileLimit` constant (agent handles limits now)
### Tests
- 13 new test cases for `TestReadFileLines`:
- Path validation (empty, relative, non-existent, directory, no
permissions)
- Empty file handling
- Basic read, offset, limit, offset+limit combinations
- Offset beyond file length
- Long line truncation (>1024 bytes)
- Large file rejection (>1MB)
- All existing tests pass unchanged
## Design decisions
| Decision | Rationale |
|---|---|
| Line-based, not byte-based | Both coder/mux and openai/codex use
line-based — matches how LLMs reason about code |
| Default limit of 2000 | Matches codex; prevents accidental full-file
dumps while being generous |
| 32 KB response cap | Compromise between mux (16 KB) and codex (no cap)
|
| 1024 byte/line truncation with marker | More generous than codex
(500), marker helps LLM know data is missing |
| Hard errors on overflow | Matches mux; forces LLM to paginate rather
than getting partial data |
| Preserve byte-based endpoint | `instruction.go` needs raw byte access
for AGENTS.md |
Fixes all our Go file imports to match the preferred spec that we've _mostly_ been using. For example:
```
import (
"context"
"time"
"github.com/prometheus/client_golang/prometheus"
"golang.org/x/xerrors"
"gopkg.in/natefinch/lumberjack.v2"
"cdr.dev/slog/v3"
"github.com/coder/coder/v2/codersdk/agentsdk"
"github.com/coder/serpent"
)
```
3 groups: standard library, 3rd partly libs, Coder libs.
This PR makes the change across the codebase. The PR in the stack above modifies our formatting to maintain this state of affairs, and is a separate PR so it's possible to review that one in detail.
Upgrades to slog v3 which includes a small, but backward incompatible API change to the acceptible call arguments when logging. This change allows us to verify via compile time type checking that arguments are correct and won't cause a panic, as was possible in slog v1, which this replaces (v2 was tagged but never used in coder/coder).
It also updates dependencies that also use slog and were updated.
I've left the `aibridge` dependency as a commit SHA, under the assumption that the team there (cc @pawbana @dannykopping ) will tag and update the dependency soon and on their own schedule.
Other dependencies, I pushed new tags.
Follows similarly to the bash tool (and some code to connect to an agent
was extracted from it).
There are two main parts: a new agent endpoint, and then a new MCP tool
that consumes that endpoint.
Fixes https://github.com/coder/internal/issues/907
We convert `workspacesdk.AgentConn` to an interface and generate a mock
for it. This allows writing `coderd` tests that rely on the agent's HTTP
api to not have to set up an entire tailnet networking stack.
Fixes https://github.com/coder/coder/issues/19372
We increase the read limit to 4MiB (we use this limit elsewhere). We
also make sure to stop sending messages when `containersCh` becomes
closed.
This PR replaces the use of the **container** ID with the
**devcontainer** ID. This is a breaking change. This allows rebuilding a
devcontainer when there is no valid container ID.
This change introduces a refactor of the devcontainers recreation logic
which is now handled asynchronously rather than being request scoped.
The response was consequently changed from "No Content" to "Accepted" to
reflect this.
A new `Status` field was introduced to the devcontainer struct which
replaces `Running` (bool). This reflects that the devcontainer can now
be in various states (starting, running, stopped or errored).
The status field also protects against multiple concurrent recrations,
as long as they are initiated via the API.
Updates #16424
Closes https://github.com/coder/vscode-coder/issues/447
Closes https://github.com/coder/jetbrains-coder/issues/543
Closes https://github.com/coder/coder-jetbrains-toolbox/issues/21
This PR adds Coder Connect support to `coder ssh --stdio`.
When connecting to a workspace, if `--force-new-tunnel` is not passed, the CLI will first do a DNS lookup for `<agent>.<workspace>.<owner>.<hostname-suffix>`. If an IP address is returned, and it's within the Coder service prefix, the CLI will not create a new tailnet connection to the workspace, and instead dial the SSH server running on port 22 on the workspace directly over TCP.
This allows IDE extensions to use the Coder Connect tunnel, without requiring any modifications to the extensions themselves.
Additionally, `using_coder_connect` is added to the `sshNetworkStats` file, which the VS Code extension (and maybe Jetbrains?) will be able to read, and indicate to the user that they are using Coder Connect.
One advantage of this approach is that running `coder ssh --stdio` on an offline workspace with Coder Connect enabled will have the CLI wait for the workspace to build, the agent to connect (and optionally, for the startup scripts to finish), before finally connecting using the Coder Connect tunnel.
As a result, `coder ssh --stdio` has the overhead of looking up the workspace and agent, and checking if they are running. On my device, this meant `coder ssh --stdio <workspace>` was approximately a second slower than just connecting to the workspace directly using `ssh <workspace>.coder` (I would assume anyone serious about their Coder Connect usage would know to just do the latter anyway).
To ensure this doesn't come at a significant performance cost, I've also benchmarked this PR.
<details>
<summary>Benchmark</summary>
## Methodology
All tests were completed on `dev.coder.com`, where a Linux workspace running in AWS `us-west1` was created.
The machine running Coder Desktop (the 'client') was a Windows VM running in the same AWS region and VPC as the workspace.
To test the performance of specifically the SSH connection, a port was forwarded between the client and workspace using:
```
ssh -p 22 -L7001:localhost:7001 <host>
```
where `host` was either an alias for an SSH ProxyCommand that called `coder ssh`, or a Coder Connect hostname.
For latency, [`tcping`](https://www.elifulkerson.com/projects/tcping.php) was used against the forwarded port:
```
tcping -n 100 localhost 7001
```
For throughput, [`iperf3`](https://iperf.fr/iperf-download.php) was used:
```
iperf3 -c localhost -p 7001
```
where an `iperf3` server was running on the workspace on port 7001.
## Test Cases
### Testcase 1: `coder ssh` `ProxyCommand` that bicopies from Coder Connect
This case tests the implementation in this PR, such that we can write a config like:
```
Host codercliconnect
ProxyCommand /path/to/coder ssh --stdio workspace
```
With Coder Connect enabled, `ssh -p 22 -L7001:localhost:7001 codercliconnect` will use the Coder Connect tunnel. The results were as follows:
**Throughput, 10 tests, back to back:**
- Average throughput across all tests: 788.20 Mbits/sec
- Minimum average throughput: 731 Mbits/sec
- Maximum average throughput: 871 Mbits/sec
- Standard Deviation: 38.88 Mbits/sec
**Latency, 100 RTTs:**
- Average: 0.369ms
- Minimum: 0.290ms
- Maximum: 0.473ms
### Testcase 2: `ssh` dialing Coder Connect directly without a `ProxyCommand`
This is what we assume to be the 'best' way to use Coder Connect
**Throughput, 10 tests, back to back:**
- Average throughput across all tests: 789.50 Mbits/sec
- Minimum average throughput: 708 Mbits/sec
- Maximum average throughput: 839 Mbits/sec
- Standard Deviation: 39.98 Mbits/sec
**Latency, 100 RTTs:**
- Average: 0.369ms
- Minimum: 0.267ms
- Maximum: 0.440ms
### Testcase 3: `coder ssh` `ProxyCommand` that creates its own Tailnet connection in-process
This is what normally happens when you run `coder ssh`:
**Throughput, 10 tests, back to back:**
- Average throughput across all tests: 610.20 Mbits/sec
- Minimum average throughput: 569 Mbits/sec
- Maximum average throughput: 664 Mbits/sec
- Standard Deviation: 27.29 Mbits/sec
**Latency, 100 RTTs:**
- Average: 0.335ms
- Minimum: 0.262ms
- Maximum: 0.452ms
## Analysis
Performing a two-tailed, unpaired t-test against the throughput of testcases 1 and 2, we find a P value of `0.9450`. This suggests the difference between the data sets is not statistically significant. In other words, there is a 94.5% chance that the difference between the data sets is due to chance.
## Conclusion
From the t-test, and by comparison to the status quo (regular `coder ssh`, which uses gvisor, and is noticeably slower), I think it's safe to say any impact on throughput or latency by the `ProxyCommand` performing a bicopy against Coder Connect is negligible. Users are very much unlikely to run into performance issues as a result of using Coder Connect via `coder ssh`, as implemented in this PR.
Less scientifically, I ran these same tests on my home network with my Sydney workspace, and both throughput and latency were consistent across testcases 1 and 2.
</details>
- Update go.mod to use Go 1.24.1
- Update GitHub Actions setup-go action to use Go 1.24.1
- Fix linting issues with golangci-lint by:
- Updating to golangci-lint v1.57.1 (more compatible with Go 1.24.1)
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
---------
Co-authored-by: Claude <claude@anthropic.com>
Fixes: https://github.com/coder/internal/issues/377
Added an additional SSH listener on port 22, so the agent now listens on both, port one and port 22.
---
Change-Id: Ifd986b260f8ac317e37d65111cd4e0bd1dc38af8
Signed-off-by: Thomas Kosiewski <tk@coder.com>
Builds on top of https://github.com/coder/coder/pull/16623/ and wires up
the ReconnectingPTY server. This does nothing to wire up the web
terminal yet but the added test demonstrates the functionality working.
Other changes:
* Refactors and moves the `SystemEnvInfo` interface to the
`agent/usershell` package to address follow-up from
https://github.com/coder/coder/pull/16623#discussion_r1967580249
* Marks `usershellinfo.Get` as deprecated. Consumers should use the
`EnvInfoer` interface instead.
---------
Co-authored-by: Mathias Fredriksson <mafredri@gmail.com>
Co-authored-by: Danny Kopping <danny@coder.com>
Fixes https://github.com/coder/coder/issues/16268
- Adds `/api/v2/workspaceagents/:id/containers` coderd endpoint that allows listing containers
visible to the agent. Optional filtering by labels is supported.
- Adds go tools to the `coder-dylib` CI step so we can generate mocks if needed
re: #14715
This PR introduces the Coder service prefix: `fd60:627a:a42b::/48` and refactors our existing code as calling the Tailscale service prefix explicitly (rather than implicitly).
Removes the unused `Addresses` agent option. All clients today assume they can compute the Agent's IP address based on its UUID, so an agent started with a custom address would break things.
First PR to address #14244.
Adds common potential reasons as to why a direct connection to the workspace agent couldn't be established to `coder ping`:
- If the Coder deployment administrator has blocked direction connections (`CODER_BLOCK_DIRECT`).
- If the client has no STUN servers within it's DERP map.
- If the client or agent appears to be behind a hard NAT, as per Tailscale `netInfo.MappingVariesByDestIP`
Also adds a warning if the client or agent has a network interface below the 'safe' MTU for tailnet. This warning is always displayed at the end of a `coder ping`.
Currently, importing `codersdk` just to interact with the API requires
importing tailscale, which causes builds to fail unless manually using
our fork.
Ethan