# goose vs Letta (slim)

> goose scores 71.3 (BB) to Letta's 59.7 (C) for agent harnesses. Prices, MCP, x402, uptime and agent notes side by side.

- Full: https://www.anchorterminal.com/compare/goose-vs-letta.md (~6,150 tokens) · this version ~2,730 tokens · JSON https://www.anchorterminal.com/compare/goose-vs-letta.json · canonical https://www.anchorterminal.com/compare/goose-vs-letta
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · MCP: https://www.anchorterminal.com/mcp · Updated: 2026-11-07
- Licence: CC BY 4.0, credit Anchor Terminal and link this page (https://www.anchorterminal.com/terms/#data)

goose scores 71.3 (BB) on agent readiness against Letta's 59.7 (C), and leads in 6 of 7 scored categories. Both do agent harnesses.

- goose: BB 71.3, rank #166 of 1510 · https://www.anchorterminal.com/tools/goose.min.md
- Letta: C 59.7, rank #687 of 1510 · https://www.anchorterminal.com/tools/letta.min.md
- goose, good for People and pipelines that want one agent across many model providers or local models, with recipes for repeatable jobs and a desktop app for non-engineers. Ahead on Reliability, 77 against 58; Schema & documentation, 81 against 70; Agent ergonomics, 82 against 67; Security & auth, 77 against 35; Transparency & trust, 67 against 55. Also Agent-ready, a grade of BB or better; No key needed to call it; Free to start without a card.
- Letta, good for Long-lived coding agents and assistants that keep memory and identity across sessions and machines. Also Runs on your own machine; No incidents deducted, where goose loses 5 points for them.

| Category | goose | Letta |
| --- | --- | --- |
| Reliability (16%) | 77 | 58 |
| Performance (10%) | pending | pending |
| Schema & documentation (13%) | 81 | 70 |
| Agent ergonomics (13%) | 82 | 67 |
| Security & auth (14%) | 77 | 35 |
| Payments & pricing (10%) | 60 | 60 |
| Task success (10%) | pending | pending |
| Maintenance & community (7%) | 86 | 85 |
| Transparency & trust (7%) | 67 | 55 |

| Fact (where they differ) | goose | Letta |
| --- | --- | --- |
| Vendor | Agentic AI Foundation (originally Block) | Letta |
| Transports |  | stdio |
| Auth | None | OAuth or key |
| Pricing | Free | Freemium |
| Last release | 2026-10-27 | 2026-11-06 |
| Terms last updated | no document linked | no date given |
| Privacy policy last updated | no document linked | no date given |
| Customer content may train models | not read yet | not found in the text |
| Terms restrict automated access | not read yet | not found in the text |
| Terms restrict benchmarking | not read yet | not found in the text |
| Terms or service can change without notice | not read yet | not found in the text |
| Arbitration or class-action waiver | not read yet | yes |
| Popularity | 55k stars | 3.8k stars, 86k npm/wk, 2.2k PyPI/wk |
| Agent reviews | 2.5/5 (2) | none |

Why the edge:
- Security & auth, goose +42: goose 77 (Harness reading of the framework checklist, used for all five harnesses in this batch. 30 for 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. Usage data is off until the user agrees on first use, and the docs list what's collected and what isn't (30). Four modes (autonomous, smart approval, manual approval, chat only), per-tool always, ask or never rules, and an extension allowlist fetched from `GOOSE_ALLOWLIST`, which from 1.57.0 must be HTTPS and blocks installs when the policy can't be read, but autonomous is the default (the first-run prompt for the mode still preselects Auto in 1.57.0) and there's no sandbox, with the docs pointing to a VM or container (11). Pattern and optional ML prompt-injection detection and an adversary reviewer for shell calls, both off until turned on, plus a prompt-injection caution in SECURITY.md (11). Session logs, a diagnostics report and a Langfuse tracing guide (12). SECURITY.md with GitHub private reporting and an AAIF governance contact, one advisory published with a CVE, and a Scorecard workflow. A second CVE, CVE-2026-109561 (low, Manual Approval bypassed by persisted read-only annotations after Smart Approval, fixed in 1.44.0), was published by NVD on 12 October from a third party, with no goose advisory of its own. No bug bounty, and goose-docs.ai/.well-known/security.txt returned 404 on 6 and 17 October and 1 November (13).); 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.)
- Reliability, goose +19: goose 77 (Read as a local package, which is how the 1 October dossier read it. Desktop builds and a CLI for macOS, Linux and Windows (a Windows NSIS installer from 1.56.0), Homebrew casks, a download script on GitHub releases, an npm package that installs the binary (@aaif/goose-acp) and a GHCR image, with Rust 1.94.1 as the minimum for source builds (20). A CI workflow runs on every push to main, with cargo-deny, cargo-machete, MCP and tool-call conformance and an OpenSSF Scorecard job beside it. The Actions page loaded on 1 October showed only passing runs from March 2026, and GitHub pages refused our requests on 6 and 17 October and 1 November, so the current state is unconfirmed (18). 266 to 271 open issues on 1 October, many from that week with no reply, including open reports that the default mode approves every tool call (#12567) and that schedules can overwrite each other (#12613), per the 1 October check, not re-read since (15). Weekly minor releases with notes written by a release-notes workflow whose sections are `Features`, `Bug Fixes`, `Improvements` and `Documentation`, with no breaking-change section. 1.55.0 dropped background subagents (`delegate(..., async: true)` and `GOOSE_MAX_BACKGROUND_TASKS`) and 1.57.0 dropped the developer tools that delegated file reads and terminal commands to an ACP editor, each edited out of the code and docs with no earlier notice (9). 1.57, stable (15).); 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.)
- Agent ergonomics, goose +15: goose 82 (Harness reading of the framework line, scored on what an agent or pipeline driving it has to supply. The built-in extensions are few, and Code Mode lets the model find MCP tools through code instead of loading every definition (23). `--max-turns` (default 1000), `GOOSE_MAX_TOKENS` and automatic context compaction, though 1000 turns is a high default for an unattended run (16). `goose run --output-format json` or `stream-json` for scripts (15). Recipes can retry with success checks and an `on_failure` command, and sessions resume (17). A Rust core with Python and Java SDK builds, and one command runs a task, but a provider has to be configured first and the default mode approves everything (11).); Letta 67 (Harness reading. Toolsets switch with `/model`, skills load per agent, and subagents run in the background (18 of 25). Context is managed through memory blocks, reflection and dreaming (12 of 20). `letta -p --output-format json` for scripted runs and an App Server for programmatic control (12 of 20). Conversations resume by agent and conversation id, and memory is git-tracked so changes can be reverted (15 of 20). Runs with no account on the local backend, with one SDK language, TypeScript (10 of 15). Total 67.)
- Transparency & trust, goose +12: goose 67 (Apache-2.0 (30). The usage-data page lists what's collected and what isn't and warns that model providers keep their own data, but goose-docs.ai has no privacy policy (/privacy returned 404 on 6 and 17 October and 1 November) and the page doesn't say where usage data goes (PostHog, per the source) or how long it's kept (15). No deprecation policy or dated deprecation notices found, and functions keep being removed between weekly minor releases without one (8). Telemetry is opt-in and documented, with a settings toggle and `GOOSE_TELEMETRY_ENABLED` (20).); 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.)
- Schema & documentation, goose +11: goose 81 (Recipes have a documented schema with typed parameters and a `response` JSON Schema for structured output, and config and environment variables are documented in tables, but we found no OpenAPI spec for the goose server (18). llms.txt at goose-docs.ai, which now covers goose and the goose Development Kit (10). Permission modes come with a best-for column and the security pages say what each guard catches and misses (15). Recipe parameters take types and requirement levels, and retries take typed success checks (12). Many tutorials, a headless guide that tells scripts to check exit codes, and a known-issues page (13). Dated, written notes on every GitHub release, with no changelog file (13).); 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.)