Ethan 181e103201 fix: reuse shared tailnet for coderd-hosted MCP workspace tools (#24460) ...

## 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

2026-04-21 11:37:10 +10:00

..

agentapi

feat: runtime user secrets injection into workspaces (#24313)

2026-04-17 16:55:24 -06:00

agentmetrics

chore: remove unnecessary redeclarations in for loops (#18440)

2025-06-20 13:16:55 -06:00

aibridge

feat: add chatgpt support for aibridge proxy (#23826)

2026-03-31 12:54:38 -04:00

aiseats

feat: track ai seat usage (#22682)

2026-03-16 12:36:26 -05:00

apidoc

feat: support multiple agents with shared instance-identity auth (#24325)

2026-04-16 13:59:09 +02:00

apikey

fix: initialize API key LastUsed to Unix epoch instead of zero time (#22327)

2026-03-02 16:02:01 +01:00

appearance

fix: make cli respect deployment --docs-url (#14568)

2024-09-18 21:47:53 +10:00

audit

chore: add audit log entry when ai seat is consumed (#22683)

2026-03-16 15:30:25 -05:00

autobuild

fix: use "idle timeout" as task auto-pause reason (#22287)

2026-02-24 16:45:56 +00:00

awsidentity

…

azureidentity

chore: update azure certs (#21265)

2025-12-15 13:44:44 -09:00

boundaryusage

fix: make boundary usage telemetry collection atomic (#21907)

2026-02-06 09:52:17 -07:00

cachecompress

fix(site): avoid duplicating bin download headers (#22981)

2026-03-13 00:22:55 +11:00

chatfiles

feat(coderd/x/chatd): agent-created file attachments in chat (#24280)

2026-04-20 18:04:35 +10:00

coderdtest

feat: add CLI commands for managing chat context from workspaces (#24105)

2026-04-09 16:33:00 +02:00

connectionlog

feat: batch connection logs to avoid DB lock contention (#23727)

2026-04-03 15:47:26 -05:00

cryptokeys

chore: arrange imports in a standard way (#21452)

2026-01-08 15:24:11 +04:00

database

feat: allow renaming of agent chat title (#24489)

2026-04-20 14:00:46 +01:00

devtunnel

chore: remove unnecessary loop variable captures (#22180)

2026-02-19 09:02:19 +00:00

dynamicparameters

refactor: replace sort.Strings with slices.Sort (#23457)

2026-03-23 23:19:23 +02:00

entitlements

feat: add Prometheus metrics for license warnings and errors (#21749)

2026-01-29 13:50:15 +01:00

externalauth

fix(coderd/externalauth): save refreshed token before validation (#24332)

2026-04-18 14:28:29 +03:00

files

chore: arrange imports in a standard way (#21452)

2026-01-08 15:24:11 +04:00

gitsshkey

chore: arrange imports in a standard way (#21452)

2026-01-08 15:24:11 +04:00

healthcheck

feat: wire DERPTLSConfig through CLI, SDK, tailnet, VPN, agent, and health checks (#24435)

2026-04-16 12:46:52 -04:00

httpapi

fix: prioritize context cancellation in WebSocket sendEvent (#23756)

2026-03-29 20:11:30 -04:00

httpmw

fix(coderd): omit frame-ancestors CSP for embed routes (#24529)

2026-04-20 15:38:52 +02:00

idpsync

test: remove unnecessary dbauthz.AsSystemRestricted calls in tests (#22663)

2026-03-05 20:29:49 +00:00

jobreaper

refactor: extract test helpers in coderd/jobreaper to reduce duplication (#23001)

2026-03-19 21:51:26 +00:00

jwtutils

chore: remove unnecessary redeclarations in for loops (#18440)

2025-06-20 13:16:55 -06:00

mcp

fix: reuse shared tailnet for coderd-hosted MCP workspace tools (#24460)

2026-04-21 11:37:10 +10:00

metricscache

chore: arrange imports in a standard way (#21452)

2026-01-08 15:24:11 +04:00

notifications

refactor: replace sort.Strings with slices.Sort (#23457)

2026-03-23 23:19:23 +02:00

oauth2provider

fix: OAuth2 cancel button in the authorization page not working (#24058)

2026-04-10 12:49:22 +03:00

oauthpki

fix(coderd): support string type for oidc response's expires_in json property (#20152)

2025-10-15 17:37:37 +00:00

portsharing

fix: properly convert max port share level for oss (#13261)

2024-05-13 14:37:51 -04:00

pproflabel

chore: add tallyman events for ai seat tracking (#22689)

2026-03-18 09:30:22 -05:00

prebuilds

fix: make prebuild claiming durable and idempotent (#23108)

2026-04-02 23:51:02 +02:00

prometheusmetrics

feat: add coder_build_info metric (#24365)

2026-04-15 12:48:38 +00:00

promoauth

fix!: remove deprecated prometheus metrics (#21788)

2026-01-30 13:30:06 +01:00

provisionerdserver

feat: support multiple agents with shared instance-identity auth (#24325)

2026-04-16 13:59:09 +02:00

provisionerkey

chore!: ensure consistent secret token generation and hashing (#20388)

2025-10-23 15:38:49 -05:00

proxyhealth

feat: add csp headers for embedded apps (#18374)

2025-06-17 09:00:32 -08:00

pubsub

refactor: send raw typed payloads over chat WebSockets (#24148)

2026-04-10 10:47:30 +01:00

rbac

perf(coderd): cheaper chatd org membership checks (#24361)

2026-04-16 00:12:54 +10:00

render

chore: remove unnecessary redeclarations in for loops (#18440)

2025-06-20 13:16:55 -06:00

runtimeconfig

chore(coderd/runtimeconfig): remove dbmem from tests (#18790)

2025-07-08 14:31:05 +00:00

schedule

chore: remove unnecessary loop variable captures (#22180)

2026-02-19 09:02:19 +00:00

searchquery

perf: cap count queries and emit native UUID comparisons for audit/connection logs (#23835)

2026-04-07 07:24:53 -07:00

taskname

fix(coderd): strip markdown code fences from Anthropic task name responses (#23024)

2026-03-13 17:35:26 +00:00

telemetry

feat(coderd): add PR status summary to telemetry snapshots (#24379)

2026-04-17 21:56:11 +10:00

testdata

feat: add flag to disable template insights (#20940)

2025-12-14 03:00:03 +00:00

tracing

fix: StatusWriter Unwrap and process output error recovery (#23383)

2026-03-20 20:00:55 +00:00

updatecheck

chore: arrange imports in a standard way (#21452)

2026-01-08 15:24:11 +04:00

usage

chore: add tallyman events for ai seat tracking (#22689)

2026-03-18 09:30:22 -05:00

userpassword

chore: remove unnecessary redeclarations in for loops (#18440)

2025-06-20 13:16:55 -06:00

util

fix(coderd): actually wire the chat template allowlist into tools (#23626)

2026-03-25 22:15:27 +00:00

webpush

fix(coderd): validate webpush subscription endpoints (#24347)

2026-04-15 11:31:43 +02:00

workspaceapps

perf(coderd): cheaper chatd org membership checks (#24361)

2026-04-16 00:12:54 +10:00

workspacestats

feat: add Prometheus metrics for chatd subsystem (#24371)

2026-04-15 19:53:10 +01:00

wsbuilder

fix(coderd): auto-update workspace to active template version on chat start (#24424)

2026-04-17 00:16:37 +10:00

wspubsub

feat: add WatchAllWorkspaceBuilds endpoint for autostart scaletests (#22057)

2026-03-13 20:37:41 -07:00

x

feat(coderd): accept parameters in start_workspace tool (#24434)

2026-04-21 11:36:20 +10:00

activitybump_test.go

test: add testutil.WaitBuffer and replace time.Sleep in tests (#22922)

2026-03-12 18:07:52 +02:00

aitasks_internal_test.go

fix: set codersdk.Task current_state during task initialization (#20692)

2025-11-17 13:24:12 +00:00

aitasks_test.go

fix: return 409 Conflict instead of 502 when task agent is busy (#23424)

2026-03-23 09:52:34 +00:00

aitasks.go

fix: return 409 Conflict instead of 502 when task agent is busy (#23424)

2026-03-23 09:52:34 +00:00

apikey_scopes_validation_test.go

feat: add multi-scope support to API keys (#19917)

2025-09-26 11:56:34 +02:00

apikey_test.go

fix: persist session cookie to disk to prevent PWA logout (#23746)

2026-04-01 09:54:59 -04:00

apikey.go

fix: persist session cookie to disk to prevent PWA logout (#23746)

2026-04-01 09:54:59 -04:00

apiroot.go

…

audit_internal_test.go

chore: add sql filter to fetching audit logs (#14070)

2024-08-01 12:07:19 -05:00

audit_test.go

chore: arrange imports in a standard way (#21452)

2026-01-08 15:24:11 +04:00

audit.go

perf: cap count queries and emit native UUID comparisons for audit/connection logs (#23835)

2026-04-07 07:24:53 -07:00

authorize_test.go

feat: add an organization member permission level (#19953)

2025-10-27 17:14:16 -06:00

authorize.go

feat: show friendly alert for missing agents-access role (#23831)

2026-03-31 17:26:58 +01:00

client_test.go

…

coderd_internal_test.go

chore: remove unnecessary redeclarations in for loops (#18440)

2025-06-20 13:16:55 -06:00

coderd_test.go

chore: switch agent gone response from 502 to 404 (#23090)

2026-03-25 09:57:28 -04:00

coderd.go

fix(coderd): omit frame-ancestors CSP for embed routes (#24529)

2026-04-20 15:38:52 +02:00

csp.go

chore: arrange imports in a standard way (#21452)

2026-01-08 15:24:11 +04:00

debug_test.go

feat(coderd): add consolidated /debug/profile endpoint for pprof collection (#22892)

2026-03-13 14:09:39 +00:00

debug.go

feat(coderd): add consolidated /debug/profile endpoint for pprof collection (#22892)

2026-03-13 14:09:39 +00:00

deployment_test.go

fix(coderd): mark provisioner daemon psk as secret (#12322)

2024-02-27 16:33:32 +00:00

deployment.go

chore: remove chats experiment (#18535)

2025-06-25 13:03:32 +00:00

deprecated.go

chore!: remove deprecated agent v1 routes (#13486)

2024-06-11 12:22:59 +10:00

exp_chats_internal_test.go

feat(coderd): accept parameters in start_workspace tool (#24434)

2026-04-21 11:36:20 +10:00

exp_chats_test.go

feat: allow renaming of agent chat title (#24489)

2026-04-20 14:00:46 +01:00

exp_chats.go

feat(coderd): accept parameters in start_workspace tool (#24434)

2026-04-21 11:36:20 +10:00

experiments_test.go

chore: revert dynamic params as a safe experiment (#17510)

2025-04-22 16:21:15 +00:00

experiments.go

fix: do not warn on valid known experiments (#18514)

2025-06-24 09:14:41 +01:00

export_test.go

feat: add CLI commands for managing chat context from workspaces (#24105)

2026-04-09 16:33:00 +02:00

externalauth_test.go

feat(coderd/rbac): make organization-member a per-org system custom role (#21359)

2026-01-12 18:19:19 -08:00

externalauth.go

feat!: support PKCE in the oauth2 client's auth/exchange flow (#21215)

2025-12-15 17:41:47 +00:00

files_test.go

test: share coderdtest instances to stop paying the startup tax 22 times (#23454)

2026-03-23 19:54:43 +00:00

files.go

chore: arrange imports in a standard way (#21452)

2026-01-08 15:24:11 +04:00

gitsshkey_test.go

chore: distinct operations for provisioner's 'parse', 'init', 'plan', 'apply', 'graph' (#21064)

2025-12-15 11:26:41 -06:00

gitsshkey.go

feat: add API key scope to restrict access to user data (#17692)

2025-05-15 15:32:52 +01:00

inboxnotifications_internal_test.go

chore: remove unnecessary redeclarations in for loops (#18440)

2025-06-20 13:16:55 -06:00

inboxnotifications_test.go

chore: remove unnecessary redeclarations in for loops (#18440)

2025-06-20 13:16:55 -06:00

inboxnotifications.go

fix(coderd): ensure inbox WebSocket is closed when client disconnects (#21652)

2026-01-26 09:24:45 +00:00

initscript_test.go

test: share coderdtest instances to stop paying the startup tax 22 times (#23454)

2026-03-23 19:54:43 +00:00

initscript.go

feat(coderd): add support for external agents to API's and provisioner (#19286)

2025-08-19 10:41:33 +02:00

insights_internal_test.go

chore: remove unnecessary redeclarations in for loops (#18440)

2025-06-20 13:16:55 -06:00

insights_test.go

fix(coderd): fix flaky TestGetUserStatusCounts timezone boundary (#22639)

2026-03-04 18:01:56 -08:00

insights.go

fix: user status change chart accommodates DST (#22191)

2026-03-04 12:54:39 +02:00

latencycheck.go

…

mcp_http.go

fix: reuse shared tailnet for coderd-hosted MCP workspace tools (#24460)

2026-04-21 11:37:10 +10:00

mcp_test.go

feat: add organization scoping to chats (#23827)

2026-04-13 12:31:25 +01:00

mcp.go

feat: add model_intent option to MCP server configs (#23717)

2026-03-27 14:23:25 +00:00

members_test.go

feat: make service accounts a Premium feature (#24020)

2026-04-07 12:25:32 -06:00

members.go

feat: display the AI add-on column in the UI on the Users and Organization Members tables (#23291)

2026-03-26 10:36:40 +00:00

notifications_test.go

chore: return 404, not 400 if missing or authz deny (#22069)

2026-02-13 08:19:07 -06:00

notifications.go

chore: arrange imports in a standard way (#21452)

2026-01-08 15:24:11 +04:00

oauth2_error_compliance_test.go

test: reduce number of coderdtest instances (#23463)

2026-03-25 09:53:06 +00:00

oauth2_metadata_test.go

refactor: add RFC-compliant enum types and use SDK as source of truth (#21468)

2026-01-15 12:41:28 +03:00

oauth2_metadata_validation_test.go

test: share coderdtest instances in OAuth2 validation tests (#23455)

2026-03-23 21:03:34 +00:00

oauth2_security_test.go

test: reduce number of coderdtest instances (#23463)

2026-03-25 09:53:06 +00:00

oauth2_test.go

fix(coderd): use dbtime.Now() instead of time.Now() in test assertions against DB timestamps (#22685)

2026-03-06 09:14:11 +00:00

oauth2.go

feat: implement oauth2 RFC 7009 token revocation endpoint (#20362)

2025-10-22 15:18:42 -05:00

organizations_test.go

chore: protect organization endpoints with license (#14001)

2024-07-25 16:07:53 -05:00

organizations.go

chore(coderd/database): remove deprecated db2sdk.List(Lazy)? methods (#21902)

2026-02-03 17:52:07 +00:00

pagination_test.go

feat: add connectionlogs API (#18628)

2025-07-15 14:55:34 +10:00

pagination.go

feat: add connectionlogs API (#18628)

2025-07-15 14:55:34 +10:00

parameters_test.go

feat: archive modules in size order until limit is hit (#21773)

2026-02-02 09:03:18 -06:00

parameters.go

chore(coderd/database): remove deprecated db2sdk.List(Lazy)? methods (#21902)

2026-02-03 17:52:07 +00:00

presets_test.go

chore: remove unnecessary loop variable captures (#22180)

2026-02-19 09:02:19 +00:00

presets.go

feat: support icon and description in preset (#18977)

2025-07-28 15:02:26 +01:00

provisionerdaemons_test.go

feat: add filtering options to provisioners list (#19378)

2025-08-21 16:03:34 -04:00

provisionerdaemons.go

chore(coderd/database): remove deprecated db2sdk.List(Lazy)? methods (#21902)

2026-02-03 17:52:07 +00:00

provisionerjobs_internal_test.go

chore: remove unnecessary redeclarations in for loops (#18440)

2025-06-20 13:16:55 -06:00

provisionerjobs_test.go

feat: add workspace build transition to provisioner job list (#24131)

2026-04-10 09:50:11 -05:00

provisionerjobs.go

feat: add workspace build transition to provisioner job list (#24131)

2026-04-10 09:50:11 -05:00

roles_test.go

chore: protect organization endpoints with license (#14001)

2024-07-25 16:07:53 -05:00

roles.go

feat: add chat-access site-wide role to gate chat creation (#23724)

2026-03-31 10:07:21 +01:00

scopes_catalog_api_test.go

feat: add external API key scopes (#19916)

2025-09-26 11:43:32 +02:00

scopes_catalog.go

feat: add external API key scopes (#19916)

2025-09-26 11:43:32 +02:00

tailnet_test.go

chore: remove unnecessary redeclarations in for loops (#18440)

2025-06-20 13:16:55 -06:00

tailnet.go

chore: arrange imports in a standard way (#21452)

2026-01-08 15:24:11 +04:00

templates_test.go

fix(coderd): allow template deletion when only prebuild workspaces remain (#23417)

2026-03-25 09:43:06 +02:00

templates.go

fix(coderd): allow template deletion when only prebuild workspaces remain (#23417)

2026-03-25 09:43:06 +02:00

templateversions_test.go

test: share coderdtest instances to stop paying the startup tax 22 times (#23454)

2026-03-23 19:54:43 +00:00

templateversions.go

feat: validate prebuild presets using dynamic parameter validation (#21858)

2026-03-03 16:50:18 +00:00

updatecheck_test.go

chore: remove unnecessary redeclarations in for loops (#18440)

2025-06-20 13:16:55 -06:00

updatecheck.go

…

userauth_test.go

test: reduce number of coderdtest instances (#23463)

2026-03-25 09:53:06 +00:00

userauth.go

refactor: replace sort.Strings with slices.Sort (#23457)

2026-03-23 23:19:23 +02:00

users_test.go

fix: revert auto-assign agents-access role enabled (#24170)

2026-04-08 20:56:17 +01:00

users.go

fix: revert auto-assign agents-access role enabled (#24170)

2026-04-08 20:56:17 +01:00

usersecrets_test.go

feat: add secret value and file path validation (#24269)

2026-04-13 07:24:34 -06:00

usersecrets.go

fix: relax secrets env var denylist for model providers (#24344)

2026-04-14 12:44:55 -06:00

webpush_internal_test.go

fix(coderd): validate webpush subscription endpoints (#24347)

2026-04-15 11:31:43 +02:00

webpush_test.go

fix(coderd): validate webpush subscription endpoints (#24347)

2026-04-15 11:31:43 +02:00

webpush.go

fix(coderd): validate webpush subscription endpoints (#24347)

2026-04-15 11:31:43 +02:00

workspaceagentportshare_test.go

feat(coderd/rbac): make organization-member a per-org system custom role (#21359)

2026-01-12 18:19:19 -08:00

workspaceagentportshare.go

docs: fix swagger documentation for DELETE port share endpoint (#18426)

2025-06-18 14:07:53 +00:00

workspaceagents_active_chat_internal_test.go

chore: add client_type field to chats and telemetry (#24342)

2026-04-16 23:57:05 +10:00

workspaceagents_chat_context_internal_test.go

feat: add CLI commands for managing chat context from workspaces (#24105)

2026-04-09 16:33:00 +02:00

workspaceagents_chat_context_test.go

chore: add client_type field to chats and telemetry (#24342)

2026-04-16 23:57:05 +10:00

workspaceagents_internal_test.go

fix(coderd): enforce workspace authz on watchChatGit (#24477)

2026-04-20 21:33:35 +10:00

workspaceagents_test.go

fix: mark connecting agents as unhealthy instead of healthy (#24044)

2026-04-09 13:21:28 +05:00

workspaceagents.go

fix: exclude subagent chats from sidebar pagination (#24404)

2026-04-20 13:19:59 +03:00

workspaceagentsrpc_internal_test.go

test: use not before in TestAgentConnectionMonitor_* (#21332)

2025-12-22 10:21:39 +04:00

workspaceagentsrpc_test.go

test: add testutil.WaitBuffer and replace time.Sleep in tests (#22922)

2026-03-12 18:07:52 +02:00

workspaceagentsrpc.go

fix: limit calls to GetWorkspaceAgentByID in agentapi (#23015)

2026-03-20 15:42:05 -05:00

workspaceapps_test.go

chore: remove unnecessary redeclarations in for loops (#18440)

2025-06-20 13:16:55 -06:00

workspaceapps.go

feat: add multi-scope support to API keys (#19917)

2025-09-26 11:56:34 +02:00

workspacebuilds_test.go

feat: add link for viewing raw build logs in workspace and template build jobs (#21727)

2026-02-03 09:45:23 +00:00

workspacebuilds.go

feat: add WatchAllWorkspaceBuilds endpoint for autostart scaletests (#22057)

2026-03-13 20:37:41 -07:00

workspaceproxies_test.go

fix: allow ports in wildcard url configuration (#11657)

2024-01-18 09:44:05 -06:00

workspaceproxies.go

feat: add MCP server configuration backend for chats (#23227)

2026-03-19 14:07:36 +00:00

workspaceresourceauth_test.go

feat: support multiple agents with shared instance-identity auth (#24325)

2026-04-16 13:59:09 +02:00

workspaceresourceauth.go

feat: support multiple agents with shared instance-identity auth (#24325)

2026-04-16 13:59:09 +02:00

workspaces_scoped_test.go

chore: add permissions to coder:workspace.* scopes for functionality (#23515)

2026-03-25 13:46:58 -05:00

workspaces_test.go

fix: mark connecting agents as unhealthy instead of healthy (#24044)

2026-04-09 13:21:28 +05:00

workspaces.go

fix: limit calls to GetWorkspaceAgentByID in agentapi (#23015)

2026-03-20 15:42:05 -05:00

workspaceupdates_test.go

chore: update testutil chan helpers (#17408)

2025-04-16 10:37:09 -06:00

workspaceupdates.go

chore: arrange imports in a standard way (#21452)

2026-01-08 15:24:11 +04:00