Coco MCP 0.5.1

What's Changed

New

• Tell users when a newer release is out, with the upgrade command for their install by @camiloazula in #126

Fixed

• JSON trees: a string is drawn as its JSON literal, on one line by @camiloazula in #110
• Response panel: the split takes what is left under the header, not the whole pane by @camiloazula in #112

Full Changelog: v0.4.0...v0.5.1

Coco MCP 0.4.0

What's Changed

New

• Server pane: a failure is shown in the settings, and said once by @camiloazula in #52
• Lists: faint rows say why they do not open by @camiloazula in #96

Fixed

• Connect: a server that answered the handshake is not reported as unreachable by @camiloazula in #81
• Server form: names its server by id, and keeps the keyring entry the server has now by @camiloazula in #82
• OAuth: an insufficient-scope refusal is a refusal, not an unreachable server by @camiloazula in #83
• Subscriptions: a failed event stream is told in plain words, without type names by @camiloazula in #84
• Server form: Connect with the settings as saved just connects, and Authorize never drops a change by @camiloazula in #86
• Server form: Save & reconnect follows the session as it is by @camiloazula in #87
• Server pane: the settings stay while their server connects by @camiloazula in #88
• Edit server: goes to the settings the pane already shows by @camiloazula in #89
• Status bar: gives the reason for a failure whenever it is not on screen by @camiloazula in #90
• Errors: an OS error in the middle of a message no longer cuts off the rest by @camiloazula in #85
• Lists: a failed reconnect keeps the last connection's lists by @camiloazula in #92
• Keyboard: Enter in a list that opens nothing goes to the settings by @camiloazula in #93
• Server view: the Settings row stays usable without a session by @camiloazula in #94
• History: Open in form waits for a session by @camiloazula in #95
• Authorize: a sign-in that does not complete keeps the server wanting one by @camiloazula in #97
• Calls: an OAuth server that refuses the login mid-session asks for a sign-in by @camiloazula in #98
• Connect: a connect that stops keeps no earlier refusal by @camiloazula in #99
• OAuth: new settings forget the old server's authorization challenge by @camiloazula in #100
• Errors: failure sentences start with a capital, and an IPv6 host stays by @camiloazula in #101
• Log: a server that ends the session is a failure there too by @camiloazula in #102
• Connect: a session that ends while its lists are read is not shown connected by @camiloazula in #103
• HTTP: a server on this machine is never reached through a proxy by @camiloazula in #106

Full Changelog: v0.3.2...v0.4.0

Coco MCP 0.3.2

What's Changed

New

• Server form: stays open until the saved server connects by @camiloazula in #48
• import-config: a file lands whole or not at all, and no keyring entry is left behind by @camiloazula in #49

Fixed

• Schema tab: a capped tree takes its rows' height beside other blocks by @camiloazula in #44
• Trees: a wheel over a capped tree is the tree's until it reaches an end by @camiloazula in #46
• Errors reach the pane as a sentence, and a refused token names the setting by @camiloazula in #47

Documentation

• README: npx coco-mcp, and the npm step of a release by @camiloazula in #39

Full Changelog: v0.3.1...v0.3.2

Coco MCP 0.3.1

What's Changed

Fixed

• Release workflow: draft, attach the binaries, then publish by @camiloazula in #37

Full Changelog: v0.3.0...v0.3.1

Coco MCP 0.2.0

What's Changed

New

• Log drawer: zoom to the full window, buttons for zoom, show/hide and clear by @camiloazula in #11
• Log drawer: rows open independently instead of one at a time by @camiloazula in #16
• Large responses: drawn as they arrive, in a detail pane split between input and response by @camiloazula in #24

Fixed

• Theme: the raw JSON editor takes its colours from the theme by @camiloazula in #14

Documentation

• Release notes: grouped by label, one line per merged PR by @camiloazula in #12

Full Changelog: v0.1.0...v0.2.0

Coco MCP 0.1.0

The first stable version of Coco MCP: debug Model Context Protocol servers in depth, from the command line or a native window. One Rust binary, coco-mcp: --cli runs a command, --desktop opens the window, both over the same crates.

Install

The archives below carry the binary for macOS (arm64 and x86_64), Linux (x86_64) and Windows (x86_64), with SHA256SUMS to check them against. Unpack one and put coco-mcp on your PATH; a file saved by a browser is quarantined on macOS until you allow it or run xattr -d com.apple.quarantine coco-mcp.

Homebrew, on macOS and Linux:

brew install camiloazula/coco/coco-mcp

Cargo builds the same tag from source (Rust 1.90 or newer):

cargo install --locked --git https://github.com/camiloazula/coco-mcp --tag v0.1.0 coco-mcp

What is in it

• Protocol. Stdio and streamable HTTP servers over rmcp, speaking both the initialize handshake (2024-11-05 to 2025-11-25) and the sessionless 2026-07-28 revision, chosen per server. Sampling, elicitation and roots answered through dialogs; keepalive, cancellation, progress, list-change and resource-update notifications.
• Window. Drawn by GPUI on the GPU: tools, resources, prompts and history with schema-generated forms, foldable JSON trees under a drawing budget, a filterable wire log, a command palette, native menus, dark and light themes. Every screen renders headless in tests, and the tour above is assembled from those frames.
• Command line. snapshot, call, read, prompt, history, diff with exit codes for breaking changes, and import and export of mcpServers configs.
• Storage. SQLite for servers, snapshots and call history; the OS keyring for bearer tokens and OAuth 2.1 credentials (PKCE, dynamic registration, loopback redirect with state check). Tokens are redacted from every export.
• Hardening. Only http(s) URLs are ever opened, list pagination and child stderr are bounded, the database file is owner-only, terminal output is sanitised.
• Quality. No unsafe code, no unwrap outside tests, every dependency under a permissive licence with cargo-deny in CI.

Licensed under MIT OR Apache-2.0.