Kimi Code CLI vs Letta

Kimi Code CLI 85

Framework reading. The kimi web server serves /openapi.json and /asyncapi.json, generated from its runtime validation schemas, but only from a running server behind auth, and the API is marked experimental. The ACP server's methods and capabilities are tabled (20). llms.txt indexes every page and each page is served as Markdown (10). The permission-mode, goal-mode and MCP pages say when to use each mode and what to avoid (16). The config reference gives type and default for each key, with enums for permission modes, output formats and rule decisions (13). Many examples, the server's error-code bands and ACP error codes are documented, but print-mode exit codes are documented only for goal runs (11). A dated changelog in the docs plus the technical changelog in the repository (15). Unchanged on 2 November; llms.txt now indexes 60 pages in two languages.

Letta 70

Harness reading. docs.letta.com serves llms.txt and a Markdown version of every page, with an applies_to block saying which backend and interface each page covers (10). TypeScript types for the Agent SDK and a documented App Server WebSocket protocol, but no JSON Schema or OpenAPI for the harness (15 of 25). Pages say when to use local or cloud backends, subagents and channels (14 of 20). Permission modes and options are typed in the SDK (12 of 15). Example applications and a remote client reference (11 of 15). Releases most days but no changelog file (8 of 15). Total 70.

Kimi Code CLI 72

2.4.1 on 30 October 2026 (30). 30 stable tags from 0.32.0 on 4 August to 2.4.1 on 30 October, plus canary builds since 29 October (20). The 18 October counts from shields.io badges are struck. The clone shows the pace directly, 95 commits from 13 authors between 18 October and 2 November and pull requests numbered past #4600, with the changelog crediting outside contributors in each release. Issue reply times couldn't be read (11). No published SDK. A TypeScript SDK sits in the repository (@moonshot-ai/kimi-code-sdk 0.22.0) marked private, the ACP server and REST API ship inside the CLI, and Homebrew core is current at 2.4.1 (5). CI with a frozen lockfile, lint and a dependency check (sherif), canary and release workflows, no Dependabot or Renovate file, and the pass state unchecked (6). 30 + 20 + 11 + 5 + 6 = 72.

Letta 85

v0.34.42 on 6 November 2026 (30). Dozens of releases in 90 days (20). Pull requests are merged daily; recent issues from users have few replies (15 of 25). npm and PyPI packages and the Agent SDK track the releases (12 of 15). Lock files, CI and nightly smoke tests (8 of 10). Total 85.

Kimi Code CLI 68

Local-package reading. An install script that verifies a checksum, npm @moonshot-ai/kimi-code with Node 22.19.0 or newer stated, and Homebrew core at 2.4.1, for macOS, Linux and Windows (20). A public CI workflow runs the build, a smoke test, sharded tests on Linux, tests on Windows, lint and typecheck. GitHub's pages answer 403 in this session, so whether it passes on main wasn't checked (15). The 18 October issue and pull-request counts came from shields.io badges, a third-party copy of GitHub data this run bars, so they are struck. The clone shows 95 commits from 13 authors since 18 October and a changelog that credits merged pull requests up to #4553 in 2.4.1, but which open issues are crashes or regressions, and how fast they're answered, couldn't be read (8). Changesets changelog with Major, Minor and Patch headings and no breaking-change label since 0.28.0. 2.2.0 made executor = "kaos" configs fail validation, 2.3.0 stopped bare-name plugin skill calls and 2.3.2, a patch, removed swarms from kimi -p and ACP (10). 2.4.1, past 1.0 (15). 20 + 15 + 8 + 10 + 15 = 68.

Letta 58

Local-software lines, read for the harness. @letta-ai/letta-code on npm with Node.js 22.19 or newer, and PyPI wheels for glibc Linux, macOS 14 and Windows x64 with Python 3.9 or newer stated (20). ci.yml, nightly update smoke tests and Telegram live smoke tests exist, but GitHub's API answered with a rate limit, so run results were unread (15 of 25, unchecked). 332 open issues and pull requests, mostly pull requests; recent bug reports such as recall reading the wrong conversation have no reply yet (15 of 25). 398 tags at 0.34.x with release notes on GitHub, no changelog file, and breaking removals such as AgentFile announced in the README (8 of 15). Pre-1.0 (0). Total 58.

Kimi Code CLI 45

Harness reading of the framework checklist. 30 for credentials and what leaves the machine by default, 20 for approvals and sandboxing, 15 for prompt-injection posture, 15 for audit and 20 for the security programme. OAuth tokens sit in 0600 files and shell keys aren't read unless named. Telemetry is on by default and, in the 2.2.0 package read on 18 October, sends events with a device ID, session ID and model name to telemetry-logs.kimi.com. Auto-update is on by default (14). Interactive sessions ask before edits and commands, and a dangerous-command guard covers rm -rf and similar, but kimi -p runs under Never Ask, where everything is approved and the guard is off, with only static deny rules left. No sandbox found, and hooks fail open (7). The MCP page warns about untrusted servers and project .kimi-code/mcp.json entries, and since 2.1.0 project config waits for workspace trust, but no prompt-injection guidance was found for fetched web pages (6). Sessions on disk, kimi export, the kimi vis session visualiser, a diagnostic log and hooks for auditing (11). SECURITY.md names private GitHub advisories and an email, supports only the latest version and gives no response time. No security.txt was found on kimi.com, kimi.ai or moonshot.ai, and OSV, read again on 2 November 2026, lists no advisories for the package, though 2.1.0 shipped security fixes (7).

Letta 35

Harness reading of the framework checklist, as for the other harnesses. 30 for what leaves the machine by default, 20 for approvals and sandboxing, 15 for injection posture, 15 for audit and 20 for the security programme. Letta Cloud is the default backend, so agent state and conversations go to Letta's servers, and telemetry is on by default (10 of 30). The default permission mode is unrestricted; standard, acceptEdits and strict are opt-in, and cloud sandboxes exist for remote work (4 of 20). No prompt-injection guidance found for fetched pages or channel messages (5 of 15). Conversation search and git history of memory give an operator a record of what the agent saw and changed (10 of 15). SECURITY.md routes reports to support@letta.com and scopes out the retired server; no security.txt, bounty or certification found (6 of 20). Total 35.

Kimi Code CLI 62

MIT (30). The docs have no privacy page for the CLI. The Kimi terms (effective 13 August 2026, NOVASCENT PRIVATE LIMITED, Singapore) let Moonshot use content to train its services unless the user opts out by email, prospectively only, and the Kimi privacy policy says content is used for training. The Kimi Platform privacy policy keeps inputs while the account is active. Neither says which applies to CLI sessions (12). The kimi server tree prints a deprecation notice until the next major version, a table names each deprecated config key and the version that replaced it, and the Python Kimi CLI was archived with a migration guide, though its notice gives no date for when old installations stop working (13). Telemetry is documented as on, with a config key and an environment variable to turn it off, but what it collects isn't listed, and print mode ignored the opt-out until 0.41.0 (9).

Letta 55

Apache-2.0 (30). The privacy policy has no date, no legal entity and no retention periods, and says hosted message data may train future models (8 of 30). The README and docs mark AgentFile, the Electron app and the V1 server as deprecated or retired, without dated notice periods (12 of 20). Telemetry is described in the privacy policy only as basic and opt-out when supported; the LETTA_CODE_TELEM=0 switch appears only in the source (5 of 20). Total 55.