v1.0.3

Fixes a timing problem in the credential file write lock. The server's tools and responses are unchanged from v1.0.2.

Fixes

• Concurrent trello-mcp auth saves retried the credential write lock every 100 ms in lockstep, so with many writers most of the 3 second timeout went to waiting, and slow Windows machines could time out. Retries now wait a random 10 to 20 ms, capped by the remaining deadline. The timeout, ownership checks, the rule that a stale lock is never removed automatically, and Windows permission retries are unchanged.

Upgrading from v1.0.2

• No migration is needed: the binary, configuration, tools, responses and health fields are unchanged apart from the reported version.
• Desktop: download trello-mcp_desktop.mcpb below, verify it against checksums.txt and install it. Desktop extensions update manually, and settings retention is not guaranteed.

Verification

• CI on Linux, macOS and Windows, including native Windows credential lock tests repeated 20 times; release publication waits for those tests on the tagged commit.
• New virtual-time tests cover lock contention and the exact deadline.
• The registry job publishes version 1.0.3 to the official MCP Registry after the GitHub release, from verified public assets.

Install or upgrade: curl -fsSL https://raw.githubusercontent.com/avhn/trello-mcp/main/install.sh | sh (Windows: irm https://raw.githubusercontent.com/avhn/trello-mcp/main/install.ps1 | iex). Desktop: download trello-mcp_desktop.mcpb below.

v1.0.2

Clearer onboarding. The installers print numbered next steps, the README leads with a sourced comparison, and the Claude Desktop extension instructions are four short steps. The server itself is unchanged from v1.0.1.

Changes since v1.0.1

• install.sh and install.ps1 print the installed version, then numbered steps: save your Trello key and token privately, register with Claude Code, reconnect. Each command sits on its own line. Interactive terminals get restrained color; NO_COLOR, TERM=dumb and captured output stay plain.
• The POSIX installer's PATH warning suggests the exact line for bash, zsh or fish, and says the printed commands work without PATH changes.
• The README is about a third of its former length and opens with token savings and a dated feature comparison against the official Atlassian server and the Node server.
• The Claude Desktop extension page and setup guide section are four numbered steps; field help is one sentence each. Detailed platform, storage and lifecycle notes live in docs/configuration.md.

Upgrading from v1.0.1

• No migration is needed: the binary, configuration, tools, responses and health fields are unchanged apart from the reported version.
• Desktop: download trello-mcp_desktop.mcpb below, verify it against checksums.txt and install it. Desktop extensions update manually, and settings retention is not guaranteed.

Verification

• CI on Linux, macOS and Windows, including offline installer tests under PowerShell 7 and Windows PowerShell 5.1.
• The registry job publishes version 1.0.2 to the official MCP Registry after the GitHub release, from verified public assets.

Install or upgrade: curl -fsSL https://raw.githubusercontent.com/avhn/trello-mcp/main/install.sh | sh (Windows: irm https://raw.githubusercontent.com/avhn/trello-mcp/main/install.ps1 | iex). Desktop: download trello-mcp_desktop.mcpb below.

v1.0.1

v1.0.1

Corrects the official MCP Registry entry. Registry version 1.0.0 was published from the repository's metadata-only template, so it lists the server without an installable package. Registry versions cannot be changed, so the owner publishes this release's validated metadata, with the Claude Desktop bundle, as registry version 1.0.1 and deprecates registry 1.0.0 in its favor. The server itself is unchanged from v1.0.0.

Changes since v1.0.0

• The metadata-only registry template moved from the repository root to packaging/registry/server.template.json, so publishing from a checkout can no longer pick it up by default. Release assets keep the generated server.json name.
• The release runbook covers any owner-authorized registry publication, requires the absolute path of the downloaded, generated server.json, and documents deprecating a version.

Upgrading from v1.0.0

• No migration is needed: the binary, configuration, tools, responses and health fields are unchanged apart from the reported version.
• Registry clients: use version 1.0.1 once it is listed; 1.0.0 has no package.
• Desktop: download trello-mcp_desktop.mcpb below, verify it against checksums.txt, install it, then check your settings. Desktop extensions update manually, and settings retention is not guaranteed.

Verification

• CI on Linux, macOS and Windows, including native Windows credential lock tests repeated 20 times; release publication waits for those tests on the tagged commit.
• Generated registry metadata is validated with the pinned official publisher before GitHub publication, and the downloaded public bytes are validated again before registry publication.

Install or upgrade: curl -fsSL https://raw.githubusercontent.com/avhn/trello-mcp/main/install.sh | sh (Windows: irm https://raw.githubusercontent.com/avhn/trello-mcp/main/install.ps1 | iex). Desktop: download trello-mcp_desktop.mcpb below.

v1.0.0

v1.0.0

v1.0.0 is the first stable release. The documented tools, arguments, defaults, responses, configuration, auth commands, saved-data reads and release naming covered by the compatibility and versioning policy no longer break without a major version: fixes ship as patches, additions as minors. One exception: an urgent security fix may break compatibility in a patch or minor release, always with a breaking-change notice and concrete migration guidance. The policy lists what is not covered, including local rate limits and deadlines, upstream Trello changes, and supported MCP protocol revisions and minimum OS versions, which follow the MCP Go SDK and Go toolchain.

Changes since v0.9.0

• Concurrent credential saves on Windows no longer fail intermittently with a misleading "check directory permissions" error: a transient permission denial while another writer releases the lock is retried until the lock deadline. A lasting permission problem is still reported with the same guidance once the 3-second lock deadline passes. Linux and macOS behavior is unchanged.
• The compatibility policy is now binding and states one current rule set; the pre-1.0 transition text is gone.
• Release publication now waits for native Windows credential and lock tests on the tagged commit.

Upgrading from v0.9.x

• No migration is needed: configuration, tool names, arguments, responses and health fields are unchanged.
• Reconnect or restart your client after updating, then call workspace_find {} for a real Trello read.
• Desktop: download trello-mcp_desktop.mcpb below, verify it against checksums.txt, install it, then check your settings. Desktop extensions update manually, and settings retention is not guaranteed.

Verification

• CI on Linux, macOS and Windows, race tests and golangci-lint; site validator and browser checks; native Windows lock tests repeated 20 times.
• Live on a scratch board: 47 of 48 tools exercised (board creation is never run) with all checks passing and every created object archived or deleted.
• Native Claude Desktop install and update were not re-run for this release.

Install or upgrade: curl -fsSL https://raw.githubusercontent.com/avhn/trello-mcp/main/install.sh | sh (Windows: irm https://raw.githubusercontent.com/avhn/trello-mcp/main/install.ps1 | iex). Desktop: download trello-mcp_desktop.mcpb below.

v0.9.0

Release candidate for v1.0.0: the compatibility policy is final, activity and position contracts are exact, and recovery messages no longer assume trello-mcp is on PATH.

Changes

• String pos values must now be decimal numbers. "16384.5" and "1e5" still work, but hex ("0x1p4"), digit separators ("1_000"), a sign ("+5"), a bare dot ("5.", ".5"), leading zeros and padding are rejected locally instead of reaching Trello, where they could place a card unpredictably. JSON numbers, top and bottom are still accepted. The range 0 < pos <= 1e20 (a local bound) is checked after conversion to a double, and Trello receives that double as a plain decimal, so "1e5" and 1e5 are both sent as 100000.
• Activity tools state the real name semantics: an omitted card or list name reuses the last name supplied for that id in the same page, otherwise it is unknown. Each page starts fresh, and the server never fetches names to fill gaps.
• Clearer tool descriptions: open-only list_find, summary-only includeDesc:false, Markdown omitting metadata in card_get, and checklist item due/memberId that may be unconfirmed. tools/list shrank from 20,801 to 20,694 characters.
• trello-mcp auth status and credential storage errors point to the installer's absolute-path auth command instead of a bare trello-mcp auth. When validation fails, the recovery matches the credential source: environment credentials must be updated or unset where they are set, a dedicated saved file is renewed with --file and its path, and the shared ~/.secrets.env store is superseded by running auth without --file or updated privately (or, when TRELLO_MCP_CREDENTIALS names that store, updated privately or replaced by pointing the override at a dedicated file). The 401 troubleshooting docs also cover credentials set in a client config.
• Every upstream HTTP failure now carries the trello API: HTTP <status> marker: nested ownership lookups report the parent request's status instead of a generic "temporary error; retry", and a 429 with a Retry-After over 30 seconds reads trello API: HTTP 429; rate limit exceeded; retry delay exceeds 30 seconds; retry later. Later calls during that 429 cooldown now fail fast with the same error instead of waiting 45 seconds for a bare deadline error.
• A comment action whose card moved to another board is refused as an ownership policy denial instead of a retryable "temporary error".
• When a wait would hold a request past its deadline, the call now fails at once instead of waiting 45 seconds for a bare deadline error: a Trello 429 cooldown reports trello API: HTTP 429; rate limit exceeded; retry after <N>s, and a local quota or header-reported exhaustion reports local rate limit: request quota exhausted; retry after <N>s (no HTTP marker, no request sent). Nested ownership checks use fixed wording for these, so they never name a resolved parent.
• Builds without a release stamp, such as go install, now report the release tag format (v0.9.0) in --version, MCP serverInfo and metadata health, matching release binaries.
• card_find rejects date-shaped before values such as 2026-10-15 or 20261015 before any request, as documented, instead of fetching the board snapshot first.
• limit accepts integral JSON numbers written as 20.0 or 2e1, matching its advertised integer schema.

Docs

• The compatibility and versioning policy is final for review and becomes binding at v1.0.0. It now covers an explicit security exception (urgent fixes may break compatibility in a patch or minor release with a bold notice and migration), upstream capability loss, and documented cursors, lists every write result shape, and covers the {error} envelope with its access denied by <policy>: and trello API: HTTP <status> markers.
• The mutation table lists the required and optional input of all 29 write and transfer tools, and the site validator checks it against the code.
• Text-limit evidence cites Trello's API reference (up to 16384 characters for board, list, checklist, check item and label names and board descriptions at creation; 256 for attachment names). Local limits are unchanged.
• The 60-second tool-call deadline and its effect on large batches are documented; local rate limits, quotas and deadlines are listed as not covered by the compatibility policy.
• Card and checklist response keys are listed, including idMembersVoted for extraFields: ["votes"], and card_get documents that start and dateLastActivity are full-detail only.
• Read-only and profile-hidden tools are documented as absent from tools/list; calling one is rejected by the MCP layer as an unknown tool.
• Activity documentation covers label and member. README is shorter; install and quick start come first.
• Official MCP registry metadata lists only the supported Desktop bundle (macOS universal, Windows amd64). Linux bundles stay owner-untested beta downloads; Linux users can also use the CLI installer.

Upgrading from v0.8.x

• Only the stricter string pos is incompatible: send a JSON number, or a string in JSON number syntax (no leading sign, leading zeros, whitespace, hex, separators or bare dot; an exponent sign such as "1e+5" is fine). Apart from source builds now reporting vX.Y.Z like release binaries and limit accepting integral forms such as 20.0, nothing else in configuration, tool names, arguments or health fields changes.
• Reconnect or restart your client after updating, then call workspace_find {} for a real Trello read.
• Desktop: download trello-mcp_desktop.mcpb below, verify it against checksums.txt, install it, then check your settings.

Verification

• CI on Linux, macOS and Windows, race tests and golangci-lint; site validator and browser checks; historical saved-state fixtures read without the current writer.
• Live on a scratch board: 47 of 48 tools exercised (board creation is never run) with all checks passing and every created object archived or deleted.
• Native Claude Desktop install and update were not re-run for this release.

Install or upgrade: curl -fsSL https://raw.githubusercontent.com/avhn/trello-mcp/main/install.sh | sh (Windows: irm https://raw.githubusercontent.com/avhn/trello-mcp/main/install.ps1 | iex). Desktop: download trello-mcp_desktop.mcpb below.

v0.8.0

Clearer recovery when Trello rejects a token, more precise partial-failure errors, and a published compatibility policy ahead of v1.0.0.

Changes

• A configured HTTP 401 or 403 no longer says credentials are missing. The error lists the likely causes (expired or revoked token, missing write scope, no access to the object) and uses workspace_find {} to tell them apart: if that read succeeds, the token is valid. trello-mcp auth validation failures use a CLI-specific message and still save nothing.
• Checklist item partial failures name the fields Trello did not confirm (for example due, memberId) and suggest checking advanced checklist availability. Item ids and progress are kept.
• customfield_set on an unknown or inaccessible custom field explains the 404 instead of returning only the raw status.
• Tool names, arguments, descriptions, TRELLO_TOOLS syntax and the health field set are unchanged; tools/list stays at 20,801 characters.

Docs

• New compatibility and versioning policy in docs/tools.md: what is covered, what is not, and how changes are signalled. It becomes binding at v1.0.0; until then the v0.7.0 stability intent applies.
• New response conventions: an absent card field means empty, false or unset, with the activity-name reuse and upload-URL redaction exceptions spelled out. Batch partial results and skipped checklists after unconfirmed card fields are documented.
• VS Code setup prefers the personal ~/.copilot/mcp-config.json (mcpServers), notes that it is shared with Copilot CLI, and warns that a root .mcp.json is also read by Claude Code. .vscode/mcp.json stays supported.
• The comparison with the official Atlassian Trello MCP server is dated and cites both the Atlassian repository and its support page, which currently disagree on coverage and workspace support.
• Read-only token scope versus TRELLO_READ_ONLY, unconfigured health, and attachment download name collisions (-1 to -100) are clarified. The README now puts install and quick start before the comparison.
• Desktop extension help covers checksum verification, manual updates, Windows amd64 only (Windows on Arm is not claimed) and that settings retention across updates is not guaranteed.
• The site checks copy buttons on every content page and validates that each FAQ answer matches its structured data.

Upgrading from v0.7.x

• No configuration changes and no breaking changes. Existing VS Code and client configurations keep working.
• Reconnect or restart your client after updating, then call workspace_find {} for a real Trello read.
• Desktop: download trello-mcp_desktop.mcpb below, verify it against checksums.txt, install it, then check your settings. macOS (universal) and Windows amd64 are supported; Linux bundles remain beta.

Verification

• CI on Linux, macOS and Windows, race tests and golangci-lint; site validator and browser checks.
• Live on a scratch board: 47 of 48 tools exercised (board creation is never run) with all checks passing and every created object archived or deleted; the new checklist and custom-field messages and a real 401 were observed live. The custom-field check used a missing field because the board has none.
• Native Claude Desktop install and update were not re-run for this release.

Install or upgrade: curl -fsSL https://raw.githubusercontent.com/avhn/trello-mcp/main/install.sh | sh (Windows: irm https://raw.githubusercontent.com/avhn/trello-mcp/main/install.ps1 | iex). Desktop: download trello-mcp_desktop.mcpb below.

v0.7.0

Claude Desktop extension is supported, and agents get a clearer way to verify Trello access.

Claude Desktop

• The Desktop extension is now supported on macOS (universal) and Windows amd64, attached to this release as trello-mcp_desktop.mcpb. It was validated on the v0.6.0 bundles; v0.7.0 was not re-run natively. Linux amd64 and arm64 bundles remain beta.
• Updating from the desktop-v0.6.0 preview to this bundle keeps the same extension identity, but settings retention was not verified: check your settings after updating.
• On Windows, local path uploads and attachment downloads stay refused even when the directory settings are filled in. Base64 uploads and URL attachments still work.
• The release now carries all bundles, a generated server.json and one checksums.txt covering every asset.

Changes

• server_health reports "access":"unverified; call workspace_find": it checks local configuration, not Trello. Call workspace_find for a real read. Desktop users need no CLI for this.
• Both installers also print a Logout: command with the absolute path. On Windows, a relative INSTALL_DIR now resolves against the PowerShell location.
• Tool descriptions say that board_find and card_find return open items only.

Docs

• Fixed the Claude Code read-only profile command (--env is variadic, so another option such as --transport must follow it before the server name), source-install paths, PowerShell rollback that keeps an existing version pin, and separate CLI and Desktop uninstall steps.
• Documented open-only discovery, card projections, the Markdown view, the 8 MiB upstream response cap and live-tested text limits. The comparison with the official Atlassian server is dated and sourced.

Upgrading from v0.6.x

• No configuration changes. Writes stay enabled by default; profiles and allowlists are unchanged.
• Reconnect or restart your client after updating. Removing the binary or extension does not revoke its Trello token; revoke access in your Trello account settings.

Install or upgrade: curl -fsSL https://raw.githubusercontent.com/avhn/trello-mcp/main/install.sh | sh (Windows: irm https://raw.githubusercontent.com/avhn/trello-mcp/main/install.ps1 | iex). Desktop: download trello-mcp_desktop.mcpb below.

v0.6.0

Lighter card listings, clearer setup handoffs, a Claude Desktop extension preview, and a license change.

License

• trello-mcp is now licensed under GPL-3.0-or-later. Releases up to and including v0.5.0 remain available under MIT. If you redistribute v0.6.0 or later, or a modified version, GPL-3.0-or-later applies.

Changes

• card_find takes includeDesc: false to leave out description previews. Across 265 real cards it cut the response by about 49% with identical ids, cursors and other fields. It cannot be combined with detail: "full".
• Text inputs have explicit limits, counted in Unicode code points: card descriptions follow Trello's documented 16,384, and other human text (names, comments, checklist items, custom-field text, nameFilter) has a local 16,384 ceiling. Over-limit values are rejected before any request, with an error that names the limit. Checklist items were previously capped at 4,096 bytes.
• server_health reports credentialSource (env, file or none) without revealing secrets or paths.
• TRELLO_READ_ONLY also accepts true and false.
• The installers print quoted, absolute-path commands for auth, read-only auth, status, version and Claude Code registration, so setup does not depend on PATH. PowerShell output escapes every single-quote character, including typographic quotes.
• The missing-credentials hint separates CLI installs (run the printed auth command) from Claude Desktop extensions (use extension settings).
• The tool catalog stays within its size budget (20,771 characters by default).

Claude Desktop extension (preview)

• MCPB bundles are built by the release workflow and published separately on the desktop-v0.6.0 pre-release, pending testing on macOS and Windows: one bundle for macOS (universal) and Windows amd64, plus Linux amd64 and arm64 betas. They are not attached to this release and are not in any directory yet.
• Credentials go into the extension's masked settings; no terminal is needed. See setup.

Docs and site

• docs/tools.md has a parameter table for every read tool and a text-limit section; the site validator checks the table against the code.
• Setup, configuration, README and site updated for the above, including clearer allowlist guidance (workspace ids or canonical names, not display names).

Upgrading from v0.5.x

• No configuration or credential changes are needed.
• Agents that list many cards can pass includeDesc: false when they do not need previews.

Install or upgrade: curl -fsSL https://raw.githubusercontent.com/avhn/trello-mcp/main/install.sh | sh (Windows: irm https://raw.githubusercontent.com/avhn/trello-mcp/main/install.ps1 | iex).

Desktop extension preview (v0.6.0)

Claude Desktop extension preview for trello-mcp v0.6.0. Not yet supported: these bundles are published for testing on macOS and Windows before they are offered generally. The CLI release is v0.6.0.

Bundles

• trello-mcp_desktop.mcpb: macOS (universal, Intel and Apple silicon) and Windows amd64. Windows on Arm is not claimed.
• trello-mcp_linux_amd64.mcpb, trello-mcp_linux_arm64.mcpb: Linux Desktop beta; pick the one for your CPU. Secure storage on Linux is unverified.
• Compare the SHA-256 of the file you download with checksums.txt on this page before installing.

Install

1. In your browser open https://trello.com/power-ups/admin and generate a personal API key (create a personal Power-Up first if needed).
2. In your browser only, replace YOUR_KEY in https://trello.com/1/authorize?key=YOUR_KEY&scope=read,write&expiration=30days&name=trello-mcp&response_type=token, open it, approve and copy the token. Use scope=read for a read-only token.
3. Claude Desktop: Settings > Extensions > Advanced settings > Extension Developer > Install Extension, select the .mcpb file and approve it.
4. Paste the key and token into the masked fields. Optionally set allowed workspaces (ids or canonical names, not display names), read-only mode and directories. Save, then restart the extension.

Never paste the key, token or your personalized authorization URL into a chat.

Test checklist

1. Ask Claude to call server_health. Expect ok and credentialSource env.
2. Ask a read question, for example "list my Trello boards" and "find cards on board X without descriptions".
3. Ask for one small write on a board you use for scratch (create and then archive a card).
4. Turn on read-only in the extension settings, restart, and confirm write tools are gone.
5. Report which OS and bundle you used, what worked, and any error text.

Full guide: setup, Claude Desktop extension.

v0.5.0

Accuracy, agent-first setup and a leaner site.

Fixes

• Clearing a card's due or start, or a label's color, now persists. Trello ignored the JSON null used before; clears now use query parameters, verified live.
• Writes are checked against Trello's response. If Trello does not apply a requested field, the tool returns an error that names the confirmed id and the unconfirmed inputs instead of reporting success. Checklist item due and memberId currently land here, because Trello ignored them in live tests.
• checklist_get with a name that does not exist lists the checklists that do.
• A group-writable home directory no longer stops the server when ~/.secrets.env is absent. auth logout says when there was nothing to remove.

Changes

• board_activity takes a filter (for example commentCard). Reading the latest 20 comments on a busy board dropped from about 338k to 14k characters.
• card_find summaries no longer include url; detail: "full" and card_get still do. Breaking.
• Tool descriptions are tighter and match each tool's real scope; the full tool list is smaller than in v0.4.2, and a test keeps it there.
• trello-mcp --help and auth --help have no side effects. The not-configured hint tells the human to run trello-mcp auth in a private terminal and reconnect.
• Installers handle --help first, reject unknown arguments, and fail instead of silently building @latest from source. Breaking for anyone relying on the source fallback.

Docs and site

• docs/setup.md: one runbook an agent can follow end to end, covering seven clients, verification, update, rollback and uninstall. docs/configuration.md: variables, precedence and security.
• README rewritten: shorter, sourced comparison with the official and other Trello MCP servers, and a line you can paste to your agent.
• Site reduced to four pages, with a copy button on every command.
• server.json adds MCP Registry metadata.

Upgrading from v0.4.x

• Agents that read url from card_find results: pass detail: "full", or call card_get.
• Installers no longer fall back to a source build. If a release asset is missing, install explicitly with go install github.com/avhn/trello-mcp/cmd/trello-mcp@v0.5.0.
• No configuration or credential changes are needed.

Install or upgrade: curl -fsSL https://raw.githubusercontent.com/avhn/trello-mcp/main/install.sh | sh (Windows: irm https://raw.githubusercontent.com/avhn/trello-mcp/main/install.ps1 | iex).