{ "data": { "a": { "slug": "earendil-pi", "name": "Pi", "vendor": "Earendil", "vendorUrl": "https://pi.dev", "kind": "harness", "category": "agent-harnesses", "summary": "Pi is an open-source terminal coding agent from Earendil, run on the owner's machine with any of 15 or more model providers. It has interactive, print, JSON and RPC modes, a TypeScript SDK and a built-in MCP client.", "url": "https://www.anchorterminal.com/tools/earendil-pi", "markdownUrl": "https://www.anchorterminal.com/tools/earendil-pi.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/earendil-pi.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/earendil-pi.json", "dns": "earendil-pi.grade.anchorterminal.com", "repo": "https://github.com/earendil-works/pi", "license": "MIT", "transports": [], "packages": [ { "registry": "npm", "name": "@earendil-works/pi-coding-agent" } ], "auth": "none", "authNotes": "No Pi account needed. Model providers are connected with `/login` (a subscription or an API key, stored in `~/.pi/agent/auth.json`) or with environment variables such as `ANTHROPIC_API_KEY`. MCP servers take headers, bearer tokens from the environment or OAuth, with tokens kept in `~/.pi/agent/mcp-auth.json`. Radius, the optional hosted gateway, needs its own sign-in or `RADIUS_API_KEY`.", "pricing": "free", "pricingNotes": "Free and MIT, with no paid edition of the harness. The owner pays the model provider. Radius, Earendil's optional hosted gateway, is an early alpha sold by prepaid credits, and no public price list was found (checked 2026-10-23).", "priceSummary": "Free · OSS", "where": "local", "x402": { "level": "no", "evidence": "No x402, MPP or L402 in the repository or the docs (checked 2026-10-23).", "endpoints": [] }, "toolCount": null, "popularity": { "githubStars": 113417, "npmWeekly": 5201697, "pypiWeekly": null, "asOf": "2026-10-08" }, "docsUrl": "https://pi.dev/docs/latest", "capabilities": [ "agent.harness", "agent.mcp-client" ], "tags": [ "open-source", "local", "free", "no-card", "typescript", "mcp", "json-output", "rpc", "no-sandbox" ], "lastRelease": "2026-10-21", "graded": true, "anchor": { "graded": true, "score": 62.6, "grade": "B", "agentReady": false, "rank": 550, "ranked": true, "rankOf": 1510, "categoryRank": 13, "methodology": "0.7", "run": "2026-10-01", "scores": { "ergonomics": 76, "maintenance": 87, "payments": 60, "reliability": 75, "schema": 84, "security": 61, "transparency": 67 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-11-01" }, "negative": -10, "negativeNotes": [ "2026-06-08. GHSA-jfgx-wxx8-mp94 (CVE-2026-54328, high). Temporary extension installs used predictable paths under the system temp directory, so another local user on a shared Linux host could plant extension code that Pi then loaded. Fixed in 0.78.1. Fixed, published and four months old, -2. https://github.com/earendil-works/pi/security/advisories/GHSA-jfgx-wxx8-mp94", "2026-06-08. GHSA-mqxh-6gq7-558m (CVE-2026-54325, medium). Before 0.79.0 Pi loaded a repository's `.pi` settings and extensions without asking, so starting it in a cloned repository could run that repository's code. Fixed in 0.79.0 with project trust. Fixed and published, -2. https://github.com/earendil-works/pi/security/advisories/GHSA-mqxh-6gq7-558m", "2026-06-08. GHSA-7v5m-pr3q-6453 (CVE-2026-54326, low, XSS in HTML session exports) and GHSA-r95r-rj6r-c39x (CVE-2026-54327, low, a race in `auth.json` permissions). Both fixed in 0.78.1. Recorded without a deduction. https://github.com/earendil-works/pi/security/advisories", "2026-10-12. Minor release 1.2.0 listed four breaking changes under Breaking Changes (the theme schema location, `before_agent_start` firing for custom-message runs, the busy-session behaviour and `pi mcp list --json` output), after patch release 1.0.3 on 5 October renamed the Azure provider, with no advance notice found for either. The changelog follows semantic versioning and these are 1.x releases. One term for breaking changes in minor and patch releases without notice, -3, as microsoft-agent-framework and agno took. https://github.com/earendil-works/pi/blob/main/packages/coding-agent/CHANGELOG.md", "2026-10-23 to 2026-10-29. Security fixes to Pi's own code are on main and in no release on 1 November 2026, the latest being 1.4.0 of 21 October. The unreleased changelog says MCP sign-in now rejects OAuth metadata URLs that aren't http or https (\"Before, a malicious MCP server could supply a `file:` or custom protocol URL\", commit 9ffd27c, 23 October), that the login dialog no longer opens non-web URLs or prints control characters (89c921d, 26 October), and that a saved \"Do not trust\" decision is no longer ignored (31ade0e, 29 October). No advisory was found. -3, as growthbook's unreleased fixes took. https://github.com/earendil-works/pi/blob/main/packages/coding-agent/CHANGELOG.md" ], "verdict": "Four default tools, a JSONL event stream, an RPC mode and MCP tools kept out of the model's declarations by default keep context small and scripting simple. Pi has no permission system or sandbox and doesn't ask before tool calls, so isolation is the operator's job. Version 1.4.0 is dated 21 October 2026.", "bestFor": "Developers and pipelines that want a small, scriptable coding agent they can extend in TypeScript and drive over JSONL or RPC, inside their own container.", "strengths": [ "Four default tools (read, bash, edit, write), with MCP tools reachable through codemode scripts and not declared to the model by default", "`--mode json` streams JSONL events and `--mode rpc` takes JSONL commands, both documented record by record, with a Python client example", "Built-in MCP client for stdio and streamable HTTP servers with OAuth, per-tool exposure settings and a conformance job in CI", "Project trust stops a repository's `.pi` settings, extensions and MCP servers loading until approved, and non-interactive modes skip them by default", "npm releases carry SLSA provenance from GitHub Actions trusted publishing, and the installer pins transitive dependencies" ], "weaknesses": [ "No permission system or sandbox. Tool calls run with the user's rights and without an approval prompt", "An anonymous install and update ping to pi.dev and a latest-version request are on by default", "Four advisories published in June 2026, one rated high and one medium, all fixed by 0.79.0. Fixes made since 23 October were unreleased on 1 November", "No privacy policy for pi.dev or the CLI found, and pi.dev has no security.txt", "Eight of the last 15 CI runs on main failed on 7 and 8 October 2026, and breaking changes ship in patch and minor releases (1.0.3, 1.2.0)" ], "agentNotes": [ "Run Pi inside a container or VM for unattended work. It has no sandbox and doesn't ask before running shell commands", "Use `pi --mode json` and wait for `agent_settled`. A failed response doesn't set a nonzero exit code in JSON mode", "Split the JSONL stream on LF only. Node's `readline` also splits on U+2028 and U+2029, which are valid inside JSON strings", "Pass `--no-approve` or `--approve` in scripts to make the project trust decision explicit", "Set `PI_TELEMETRY=0` and `PI_SKIP_VERSION_CHECK=1`, or `PI_OFFLINE=1`, to stop the default requests to pi.dev" ], "metrics": { "kind": "local", "measured": false }, "reviewCount": 4, "avgRating": 3.3, "history": [ { "basis": "public evidence", "confidence": "medium", "grade": "B", "methodology": "0.7", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 62.6 } ], "editorialScores": { "ergonomics": 76, "maintenance": 87, "payments": 60, "reliability": 75, "schema": 84, "security": 61, "transparency": 64 }, "provenanceScore": 69, "checked": { "categories": { "ergonomics": "2026-11-01", "maintenance": "2026-11-01", "payments": "2026-11-01", "reliability": "2026-11-01", "schema": "2026-11-01", "security": "2026-11-01", "transparency": "2026-11-01" }, "last": "2026-11-01", "lastMoved": "2026-11-01", "oldest": "2026-11-01", "stale": false, "staleAfterDays": 90 } }, "connect": { "install": "curl -fsSL https://pi.dev/install.sh | sh # or: npm install -g --ignore-scripts @earendil-works/pi-coding-agent", "headless": { "command": "pi --mode json --no-session --no-approve \"$TASK\"", "env": { "PI_SKIP_VERSION_CHECK": "1", "PI_TELEMETRY": "0" } } }, "letme": { "capability": "https://letme.dev/agent.harness", "tool": "https://letme.dev/earendil-pi" }, "area": "frameworks", "provenance": { "legalEntity": "Earendil Inc.", "domain": "pi.dev", "domainRegistered": "2024-01-30", "endpointOnVendorDomain": null, "terms": "", "privacy": "", "statusPage": "", "changelog": "https://pi.dev/changelog", "securityTxt": "none", "checked": "2026-11-01", "notes": [ "The pi.dev, earendil.com and radius.earendil.com footers read Earendil Inc. The Radius alpha terms of 1 September 2026 name Earendil Works Co., and the README calls the company Earendil Works.", "We found no terms or privacy page for pi.dev or the CLI. pi.dev/terms, pi.dev/privacy, earendil.com/privacy and radius.earendil.com/privacy return 404 (23 October 2026; pi.dev/terms and pi.dev/privacy again on 1 November 2026). Terms exist only for Radius, at radius.earendil.com/terms.", "pi.dev/.well-known/security.txt returns 404 (23 October and 1 November 2026) and earendil.com/.well-known/security.txt returned 404 (23 October 2026). SECURITY.md gives security@earendil.com and GitHub private reporting.", "RDAP for pi.dev gives a registration date of 2024-01-30 with Cloudflare as registrar. The README says the domain was donated by exe.dev.", "The repository moved from badlogic/pi-mono to earendil-works/pi, and the npm package from @mariozechner/pi-coding-agent to @earendil-works/pi-coding-agent at 0.74.0, per the advisories." ], "score": 69 }, "pageJsonUrl": "https://www.anchorterminal.com/tools/earendil-pi.json", "live": { "slug": "earendil-pi", "versions": [ { "registry": "github", "name": "earendil-works/pi", "version": "v1.5.0", "released": "2026-11-02", "seenAt": "2026-11-06T23:23:11.66948223Z" }, { "registry": "npm", "name": "@earendil-works/pi-coding-agent", "version": "1.5.0", "seenAt": "2026-11-06T23:23:11.446666701Z" } ], "githubStars": 120503, "npmWeekly": 6067871, "securityTxt": { "url": "https://pi.dev/.well-known/security.txt", "state": "none", "checkedAt": "2026-11-07T15:59:52.683123313Z" }, "domain": { "domain": "pi.dev", "registered": "2024-01-30", "source": "https://pubapi.registry.google/rdap/domain/pi.dev", "checkedAt": "2026-11-01T14:24:30.063651336Z" }, "pages": [ { "url": "https://pi.dev/changelog", "kind": "deprecations", "status": 200, "checkedAt": "2026-11-07T14:16:26.732700883Z", "changedAt": "2026-11-03T07:55:44.918705875Z", "fingerprint": "8f309eae070e" } ], "github": { "repo": "earendil-works/pi", "checkedAt": "2026-11-02T08:45:40.305774501Z", "stars": 119451, "archived": false, "issuesEnabled": true, "pushedAt": "2026-11-02T08:38:33Z", "openIssues": 243, "openPRs": 73, "issuesOpened90d": 2943, "issuesClosed90d": 2773, "prsMerged90d": 349, "ci": { "branch": "main", "runs": 50, "success": 36, "failure": 5, "other": 9, "latest": "success", "latestAt": "2026-11-01T23:16:53Z" }, "advisories": [ { "ghsa": "GHSA-mqxh-6gq7-558m", "cve": "CVE-2026-54325", "severity": "medium", "published": "2026-06-08T15:54:14Z" }, { "ghsa": "GHSA-jfgx-wxx8-mp94", "cve": "CVE-2026-54328", "severity": "high", "published": "2026-06-08T15:54:13Z" }, { "ghsa": "GHSA-r95r-rj6r-c39x", "cve": "CVE-2026-54327", "severity": "low", "published": "2026-06-08T15:54:12Z" }, { "ghsa": "GHSA-7v5m-pr3q-6453", "cve": "CVE-2026-54326", "severity": "low", "published": "2026-06-08T15:54:11Z" } ] }, "updatedAt": "2026-11-07T15:59:52.683123313Z" } }, "answer": "Pi scores 62.6 (B) on agent readiness against Letta's 59.7 (C), and leads in 6 of 7 scored categories.", "b": { "slug": "letta", "name": "Letta", "vendor": "Letta", "vendorUrl": "https://www.letta.com", "kind": "harness", "category": "agent-harnesses", "summary": "Letta, from the MemGPT team, is an open-source agent harness (formerly Letta Code) for stateful agents that keep memory blocks, skills and conversations across sessions, used from a CLI, chat.letta.com, messaging channels or the Agent SDK, with Letta Cloud.", "url": "https://www.anchorterminal.com/tools/letta", "markdownUrl": "https://www.anchorterminal.com/tools/letta.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/letta.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/letta.json", "dns": "letta.grade.anchorterminal.com", "repo": "https://github.com/letta-ai/letta-code", "license": "Apache-2.0", "transports": [ "stdio" ], "packages": [ { "registry": "npm", "name": "@letta-ai/letta-code" }, { "registry": "pypi", "name": "letta" } ], "auth": "mixed", "authNotes": "Local use needs only the user's own model keys or coding-plan logins through `/connect`. Signing in with Letta (`/login`, OAuth in the browser) stores agents in Letta Cloud and enables remote computers and secrets. Developer plans use Letta API keys.", "pricing": "freemium", "pricingNotes": "Free plan at $0 with bring-your-own keys and limited agents and storage. Pro $20 a month with Letta Auto quotas and up to 20 agents. API plan $20 a month plus $0.10 per active agent a month and $0.00015 a second of tool execution, with LLM usage at token cost.", "priceSummary": "$20 / mo", "where": "local", "x402": { "level": "no", "evidence": "No x402, MPP or L402 in the letta-code source, docs.letta.com's llms.txt or the pricing page (checked 2026-11-06).", "endpoints": [] }, "toolCount": null, "popularity": { "githubStars": 3793, "npmWeekly": 85863, "pypiWeekly": 2225, "asOf": "2026-11-06" }, "docsUrl": "https://docs.letta.com", "llmsTxt": "https://docs.letta.com/llms.txt", "capabilities": [ "agent.harness", "agent.mcp-client", "agent.multi-agent", "memory.store", "memory.search" ], "tags": [ "open-source", "local", "hosted", "freemium", "apache-2.0", "typescript", "cli", "headless", "telemetry", "llms-txt", "memory" ], "lastRelease": "2026-11-06", "graded": true, "anchor": { "graded": true, "score": 59.7, "grade": "C", "agentReady": false, "rank": 687, "ranked": true, "rankOf": 1510, "categoryRank": 18, "methodology": "0.7", "run": "2026-10-01", "scores": { "ergonomics": 67, "maintenance": 85, "payments": 60, "reliability": 58, "schema": 70, "security": 35, "transparency": 55 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-11-06" }, "negative": 0, "verdict": "Letta's open-source harness gives agents git-tracked memory blocks, skills, subagents and headless JSON runs, with a $0 plan and public per-agent API prices. It starts in the unrestricted permission mode, defaults to Letta Cloud, sends usage telemetry unless LETTA_CODE_TELEM=0 is set, and the V1 API server the comparisons describe is retired.", "bestFor": "Long-lived coding agents and assistants that keep memory and identity across sessions and machines.", "strengths": [ "Apache-2.0 harness on npm and PyPI with 0.34.42 released on 6 November 2026, and releases most days", "Memory blocks and MemFS keep an agent's context in git, with optional sync to the user's own repository", "Headless runs with `-p` and `--output-format json`, plus a TypeScript Agent SDK and a self-hosted App Server", "Public prices, a $0 plan with bring-your-own keys, and an API plan at $20 a month plus $0.10 per active agent", "Runs locally without signing in, with `letta backend local` or `--backend local`" ], "weaknesses": [ "The default permission mode is `unrestricted`, the renamed `bypassPermissions`, so tool calls aren't confirmed unless the user picks another mode", "Letta Cloud is the default backend, so agent memory and conversations go to Letta's servers unless the user chooses local", "Usage telemetry is on by default, with the LETTA_CODE_TELEM=0 opt-out found only in the source", "The Letta V1 Python API server is retired and unsupported, and the letta-ai/letta repository is now a landing page", "The privacy policy names no legal entity or date and says hosted message data may train future models" ], "agentNotes": [ "Start headless runs with an explicit permission mode such as `standard` or `strict`; the default auto-approves tools", "Pass `--backend local` for work that must stay on the machine, since Letta Cloud is the default", "Set LETTA_CODE_TELEM=0 in unattended runs if usage events must not be sent", "Use `letta -p --output-format json` for scripted runs and parse the JSON, not the terminal output", "Don't plan on the retired V1 REST server or `.af` AgentFile import; both are gone" ], "metrics": { "kind": "local", "measured": false }, "reviewCount": 0, "avgRating": 0, "history": [ { "basis": "public evidence", "confidence": "medium", "grade": "C", "methodology": "0.7", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 59.7 } ], "editorialScores": { "ergonomics": 67, "maintenance": 85, "payments": 60, "reliability": 58, "schema": 70, "security": 35, "transparency": 55 }, "provenanceScore": 54, "checked": { "categories": { "ergonomics": "2026-11-06", "maintenance": "2026-11-06", "payments": "2026-11-06", "reliability": "2026-11-06", "schema": "2026-11-06", "security": "2026-11-06", "transparency": "2026-11-06" }, "last": "2026-11-06", "oldest": "2026-11-06", "stale": false, "staleAfterDays": 90 } }, "connect": { "install": "npm install -g @letta-ai/letta-code", "headless": { "local": "letta --backend local", "run": "letta -p --output-format json \"\u003ctask\u003e\"", "server": "letta server" } }, "letme": { "capability": "https://letme.dev/agent.harness", "tool": "https://letme.dev/letta" }, "alsoIn": [ "agent-memory" ], "area": "frameworks", "unitPrices": [ { "item": "Pro plan", "unit": "month", "usd": 20, "note": "Letta Auto quotas, up to 20 agents" }, { "item": "API plan active agent", "unit": "month", "usd": 0.1, "note": "Plus $20 a month base and $0.00015 a second of tool execution" } ], "provenance": { "legalEntity": "", "domain": "letta.com", "domainRegistered": "1997-10-01", "endpointOnVendorDomain": null, "terms": "https://www.letta.com/terms-of-service", "privacy": "https://www.letta.com/privacy-policy", "statusPage": "", "changelog": "https://github.com/letta-ai/letta-code/releases", "securityTxt": "none", "checked": "2026-11-06", "notes": [ "The privacy policy shows no last-updated date and names no legal entity, only Letta. It says hosted message data may be used to train new models and that basic telemetry can be turned off in settings when supported.", "www.letta.com and docs.letta.com robots.txt allow all crawlers.", "RDAP gives letta.com a registration date of 1 October 1997, which predates the company, so the domain was bought later.", "/.well-known/security.txt returns 404. SECURITY.md in letta-ai/letta asks for reports to support@letta.com.", "The terms URL is the conventional path and was not read; the policy reader checks it at landing." ], "score": 54 }, "pageJsonUrl": "https://www.anchorterminal.com/tools/letta.json", "live": { "slug": "letta", "versions": [ { "registry": "github", "name": "letta-ai/letta-code", "version": "v0.34.43", "released": "2026-11-06", "seenAt": "2026-11-06T23:39:39.434291816Z" }, { "registry": "npm", "name": "@letta-ai/letta-code", "version": "0.34.43", "seenAt": "2026-11-06T23:39:38.413416142Z" }, { "registry": "pypi", "name": "letta", "version": "0.34.12", "released": "2026-10-12", "seenAt": "2026-11-06T23:39:39.241816797Z" } ], "githubStars": 3794, "npmWeekly": 85863, "pypiWeekly": 2225, "securityTxt": { "url": "https://letta.com/.well-known/security.txt", "state": "none", "checkedAt": "2026-11-07T16:01:02.768002207Z" }, "llmsTxt": { "url": "https://docs.letta.com/llms.txt", "ok": true, "status": 200, "checkedAt": "2026-11-07T15:32:52.28674296Z" }, "pages": [ { "url": "https://www.letta.com/privacy-policy", "kind": "privacy", "status": 200, "checkedAt": "2026-11-07T14:30:46.549817082Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "947a68f3e3a0" }, { "url": "https://www.letta.com/terms-of-service", "kind": "terms", "status": 200, "checkedAt": "2026-11-07T14:30:48.740250784Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "63f31d6ebfb8" } ], "updatedAt": "2026-11-07T16:01:02.768002207Z" } }, "edges": [ { "by": 26, "category": "security", "leads": "earendil-pi", "name": "Security \u0026 auth", "reasons": { "a": "Harness reading of the framework checklist, used for the harnesses in this category. 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. An anonymous install and update ping to pi.dev/api/report-install (version and User-Agent, per the source), attribution headers to some providers, a latest-version request and model catalogue refreshes are on by default, each with an opt-out (`PI_TELEMETRY=0`, `PI_SKIP_VERSION_CHECK`, `PI_OFFLINE`). Since 1.4.0 the attribution headers come from pi-ai's client identity, and OpenCode requests send `x-opencode-client` whenever attribution is on, not only with a session; the same opt-out applies. Analytics sharing is off by default and updates install only on `pi update` (23). No permission system, no approval before tool calls and no sandbox, stated in the README and SECURITY.md. Project trust gates a repository's `.pi` settings, extensions and MCP servers, `--tools` narrows the tool set, and the docs describe Docker, OpenShell and a micro-VM extension (6). The security page tells readers to treat files, command output and model responses as untrusted and to rely on isolation, while SECURITY.md puts prompt injection out of scope and context files such as AGENTS.md load whatever the trust decision (7). Sessions are JSONL files on disk with HTML export, MCP server logs go to `~/.pi/agent/mcp.log`, and the JSON stream records each tool call (11). SECURITY.md gives security@earendil.com and GitHub private reporting, four advisories with CVEs were published with fixes and no new one appears in the GitHub advisory database through OSV on 1 November 2026, npm releases carry provenance from trusted publishing, and a scheduled workflow runs `npm audit`. Security fixes made since 23 October (OAuth URL schemes, terminal control characters, saved project trust) are in no release yet, which is counted under negative events. No security.txt and no bounty found (14).", "b": "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." }, "scores": { "a": 61, "b": 35 } }, { "by": 17, "category": "reliability", "leads": "earendil-pi", "name": "Reliability", "reasons": { "a": "Read as a local package. `@earendil-works/pi-coding-agent` 1.4.0 on npm (still the latest on 1 November 2026) with Node.js 22.19 or newer stated, install scripts for macOS, Linux and Windows, Nix and standalone binaries (20). A public CI workflow builds, checks and tests on every push to main and runs an MCP client conformance job. The run on the commit we cloned (ce950d7, 8 October 2026) passed, but eight of the last 15 runs on main, all on 7 and 8 October, failed. Run results weren't readable on 23 October, so this stands per the 8 October check (15). The repository API reported 308 open issues and pull requests against 113,417 stars on 8 October, not re-read on 23 October. Issues from new contributors are closed automatically and reviewed daily by maintainers, per CONTRIBUTING.md, so the open count understates what is reported, and we couldn't sample reply times (16). A dated changelog with Breaking Changes sections and migration steps, but breaking changes ship outside major versions. The Azure provider rename shipped in patch release 1.0.3 on 5 October 2026, minor release 1.2.0 on 12 October carried four (theme schema location, `before_agent_start`, busy-session behaviour and `pi mcp list --json` output), and 1.3.0 required `/v1` on `kimi-coding` base URL overrides under Changed. The same reading as agent-zero and mistral-vibe-cli, and these breaks also take a deduction under negative events (9). 1.4.0 on 21 October 2026, with 1.0.0 dated 1 October 2026 (15).", "b": "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." }, "scores": { "a": 75, "b": 58 } }, { "by": 14, "category": "schema", "leads": "earendil-pi", "name": "Schema \u0026 documentation", "reasons": { "a": "Harness reading, as for the other harnesses. JSON Schemas for settings, models, keybindings and themes ship in the package and, since 1.2.0 on 12 October 2026, at pi.dev/schemas/, and the JSON event stream and every RPC command are documented record by record, but as Markdown and TypeScript types with no machine-readable spec for the RPC protocol (18). pi.dev/llms.txt returns 404. Each docs page answers `Accept: text/markdown` with Markdown, and the docs ship inside the npm package (8). The integration page has a table saying when to use interactive, print, JSON, RPC or the SDK, and the MCP page gives a typical use for each exposure setting. 1.4.0 adds a Models Configuration reference generated from the `models.json` schema (17). Enumerated modes, thinking levels and exposure values, typed settings with defaults (13). A Python RPC client, a typed TypeScript client and about 75 example extensions, with command errors and parse errors shown as records (13). A dated changelog in the repository and at pi.dev/changelog with an RSS feed (15).", "b": "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." }, "scores": { "a": 84, "b": 70 } }, { "by": 12, "category": "transparency", "leads": "earendil-pi", "name": "Transparency \u0026 trust", "reasons": { "a": "MIT (30). No privacy policy for pi.dev or the CLI was found (pi.dev/privacy, earendil.com/privacy and radius.earendil.com/privacy return 404 on 23 October 2026, and pi.dev/privacy and pi.dev/terms again on 1 November). The docs say where sessions and credentials are stored and what `/share` and `/bug` upload. The Radius alpha terms of 1 September 2026 name Earendil Works Co. and refer to a Privacy Notice we couldn't locate (10). Breaking changes are listed per release with migration steps, with no deprecation policy or notice period found. Pi Durable's README says its API changes without notice between releases (8). Install telemetry and the version check are documented in the settings and environment-variable pages with opt-outs, though the docs don't list the fields sent (16).", "b": "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." }, "scores": { "a": 67, "b": 55 } }, { "by": 9, "category": "ergonomics", "leads": "earendil-pi", "name": "Agent ergonomics", "reasons": { "a": "Harness reading of the framework line, scored on what an agent or pipeline driving it has to supply. Four default tools (read, bash, edit, write) and a short system prompt. MCP tools default to `codemode` exposure, which keeps them out of the model's tool declarations, and `tool_search` loads deferred ones on demand (23). Automatic compaction, agent-level retry with three attempts and exponential backoff, and truncated tool output saved to a file. We found no turn or step limit in the CLI or settings reference (13). `--mode json` streams JSONL events ending in `agent_settled` and `--mode rpc` returns `success: false` with an error string. Print mode exits nonzero on a failed response, JSON mode doesn't (16). Sessions are stored as trees and continue, fork or take a fixed ID with `--continue`, `--fork` and `--session-id`. File changes have no built-in undo, and a git checkpoint is an example extension (14). It needs a provider key or subscription login before the first run, and the SDK is TypeScript only, with RPC for other languages (10).", "b": "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." }, "scores": { "a": 76, "b": 67 } } ], "facts": [ { "a": "Agent harness", "b": "Agent harness", "name": "Kind" }, { "a": "Earendil", "b": "Letta", "name": "Vendor" }, { "a": "no (local only)", "b": "no (local only)", "name": "Hosted endpoint" }, { "a": "", "b": "stdio", "name": "Transports" }, { "a": "None", "b": "OAuth or key", "name": "Auth" }, { "a": "Free", "b": "Freemium", "name": "Pricing" }, { "a": "no", "b": "no", "name": "x402" }, { "a": "MIT", "b": "Apache-2.0", "name": "Licence" }, { "a": "no", "b": "no", "name": "Read-only variant documented" }, { "a": "no", "b": "yes", "name": "llms.txt" }, { "a": "2026-10-21", "b": "2026-11-06", "name": "Last release" }, { "a": "no document linked", "b": "no date given", "name": "Terms last updated" }, { "a": "no document linked", "b": "no date given", "name": "Privacy policy last updated" }, { "a": "not read yet", "b": "not found in the text", "name": "Customer content may train models" }, { "a": "not read yet", "b": "not found in the text", "name": "Terms restrict automated access" }, { "a": "not read yet", "b": "not found in the text", "name": "Terms restrict benchmarking" }, { "a": "not read yet", "b": "not found in the text", "name": "Terms or service can change without notice" }, { "a": "not read yet", "b": "yes", "name": "Arbitration or class-action waiver" }, { "a": "113k stars, 5.2M npm/wk", "b": "3.8k stars, 86k npm/wk, 2.2k PyPI/wk", "name": "Popularity" }, { "a": "3.3/5 (4)", "b": "none", "name": "Agent reviews" } ], "faq": [ { "answer": "Pi scores 62.6 (B) on agent readiness against Letta's 59.7 (C), and leads in 6 of 7 scored categories.", "question": "Which is better for AI agents, Pi or Letta?" }, { "answer": "Yes. Pi is open source (MIT). Letta is open source (Apache-2.0).", "question": "Are Pi and Letta open source?" } ], "goodFor": [ { "aheadOn": [ "Reliability, 75 against 58", "Schema \u0026 documentation, 84 against 70", "Agent ergonomics, 76 against 67", "Security \u0026 auth, 61 against 35", "Transparency \u0026 trust, 67 against 55" ], "also": [ "No key needed to call it", "Free to start without a card" ], "goodFor": "Developers and pipelines that want a small, scriptable coding agent they can extend in TypeScript and drive over JSONL or RPC, inside their own container.", "slug": "earendil-pi", "watchFor": "No permission system or sandbox. Tool calls run with the user's rights and without an approval prompt" }, { "aheadOn": null, "also": [ "Runs on your own machine", "No incidents deducted, where Pi loses 10 points for them" ], "goodFor": "Long-lived coding agents and assistants that keep memory and identity across sessions and machines.", "slug": "letta", "watchFor": "The default permission mode is `unrestricted`, the renamed `bypassPermissions`, so tool calls aren't confirmed unless the user picks another mode" } ], "history": { "earendil-pi": [ { "causes": [ "event" ], "date": "2026-11-01", "delta": -6, "from": 68.6, "fromGrade": "B", "to": 62.6, "toGrade": "B" }, { "causes": [ "method" ], "date": "2026-10-27", "delta": 0.2, "from": 68.4, "fromGrade": "B", "to": 68.6, "toGrade": "B" } ], "letta": null }, "job": { "capability": "agent.harness", "name": "Agent harnesses" }, "others": [ { "json": "https://www.anchorterminal.com/compare/agent-zero-vs-earendil-pi.json", "title": "Agent Zero vs Pi", "url": 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vs Letta", "url": "https://www.anchorterminal.com/compare/axlr-vs-letta" }, { "json": "https://www.anchorterminal.com/compare/claude-code-vs-earendil-pi.json", "title": "Claude Code vs Pi", "url": "https://www.anchorterminal.com/compare/claude-code-vs-earendil-pi" }, { "json": "https://www.anchorterminal.com/compare/claude-code-vs-letta.json", "title": "Claude Code vs Letta", "url": "https://www.anchorterminal.com/compare/claude-code-vs-letta" }, { "json": "https://www.anchorterminal.com/compare/cline-vs-earendil-pi.json", "title": "Cline vs Pi", "url": "https://www.anchorterminal.com/compare/cline-vs-earendil-pi" }, { "json": "https://www.anchorterminal.com/compare/cline-vs-letta.json", "title": "Cline vs Letta", "url": "https://www.anchorterminal.com/compare/cline-vs-letta" }, { "json": "https://www.anchorterminal.com/compare/conductor-vs-earendil-pi.json", "title": "Conductor vs Pi", "url": "https://www.anchorterminal.com/compare/conductor-vs-earendil-pi" }, { "json": "https://www.anchorterminal.com/compare/conductor-vs-letta.json", "title": "Conductor vs Letta", "url": "https://www.anchorterminal.com/compare/conductor-vs-letta" }, { "json": "https://www.anchorterminal.com/compare/crush-vs-earendil-pi.json", "title": "Crush vs Pi", "url": "https://www.anchorterminal.com/compare/crush-vs-earendil-pi" }, { "json": "https://www.anchorterminal.com/compare/crush-vs-letta.json", "title": "Crush vs Letta", "url": "https://www.anchorterminal.com/compare/crush-vs-letta" }, { "json": "https://www.anchorterminal.com/compare/cursor-cli-vs-earendil-pi.json", "title": "Cursor CLI vs Pi", "url": "https://www.anchorterminal.com/compare/cursor-cli-vs-earendil-pi" }, { "json": "https://www.anchorterminal.com/compare/cursor-cli-vs-letta.json", "title": "Cursor CLI vs Letta", "url": "https://www.anchorterminal.com/compare/cursor-cli-vs-letta" }, { "json": "https://www.anchorterminal.com/compare/deepseek-harness-vs-earendil-pi.json", "title": "DeepSeek Harness (dsh) vs Pi", "url": "https://www.anchorterminal.com/compare/deepseek-harness-vs-earendil-pi" }, { "json": "https://www.anchorterminal.com/compare/deepseek-harness-vs-letta.json", "title": "DeepSeek Harness (dsh) vs Letta", "url": "https://www.anchorterminal.com/compare/deepseek-harness-vs-letta" }, { "json": "https://www.anchorterminal.com/compare/deepseek-superagent-vs-earendil-pi.json", "title": "dsh-superagent (DeepSeek) vs Pi", "url": "https://www.anchorterminal.com/compare/deepseek-superagent-vs-earendil-pi" }, { "json": "https://www.anchorterminal.com/compare/deepseek-superagent-vs-letta.json", "title": "dsh-superagent (DeepSeek) vs Letta", "url": "https://www.anchorterminal.com/compare/deepseek-superagent-vs-letta" }, { "json": "https://www.anchorterminal.com/compare/devin-vs-earendil-pi.json", "title": "Devin vs Pi", "url": "https://www.anchorterminal.com/compare/devin-vs-earendil-pi" }, { "json": "https://www.anchorterminal.com/compare/devin-vs-letta.json", "title": "Devin vs Letta", "url": "https://www.anchorterminal.com/compare/devin-vs-letta" }, { "json": "https://www.anchorterminal.com/compare/droid-cli-vs-earendil-pi.json", "title": "Droid CLI vs Pi", "url": "https://www.anchorterminal.com/compare/droid-cli-vs-earendil-pi" }, { "json": "https://www.anchorterminal.com/compare/droid-cli-vs-letta.json", "title": "Droid CLI vs Letta", "url": "https://www.anchorterminal.com/compare/droid-cli-vs-letta" }, { "json": "https://www.anchorterminal.com/compare/earendil-pi-vs-emdash.json", "title": "Pi vs Emdash", "url": "https://www.anchorterminal.com/compare/earendil-pi-vs-emdash" }, { "json": "https://www.anchorterminal.com/compare/earendil-pi-vs-gemini-cli.json", "title": "Pi vs Gemini CLI", "url": "https://www.anchorterminal.com/compare/earendil-pi-vs-gemini-cli" }, { "json": "https://www.anchorterminal.com/compare/earendil-pi-vs-github-copilot-cli.json", "title": "Pi vs GitHub Copilot CLI", "url": 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"https://www.anchorterminal.com/compare/earendil-pi-vs-kilo-code-cli.json", "title": "Pi vs Kilo Code CLI", "url": "https://www.anchorterminal.com/compare/earendil-pi-vs-kilo-code-cli" }, { "json": "https://www.anchorterminal.com/compare/earendil-pi-vs-kimi-code-cli.json", "title": "Pi vs Kimi Code CLI", "url": "https://www.anchorterminal.com/compare/earendil-pi-vs-kimi-code-cli" }, { "json": "https://www.anchorterminal.com/compare/earendil-pi-vs-kiro-cli.json", "title": "Pi vs Kiro CLI", "url": "https://www.anchorterminal.com/compare/earendil-pi-vs-kiro-cli" }, { "json": "https://www.anchorterminal.com/compare/earendil-pi-vs-mini-swe-agent.json", "title": "Pi vs mini-swe-agent", "url": "https://www.anchorterminal.com/compare/earendil-pi-vs-mini-swe-agent" }, { "json": "https://www.anchorterminal.com/compare/earendil-pi-vs-minimax-code.json", "title": "Pi vs MiniMax Code", "url": "https://www.anchorterminal.com/compare/earendil-pi-vs-minimax-code" }, { "json": "https://www.anchorterminal.com/compare/earendil-pi-vs-mistral-vibe-cli.json", "title": "Pi vs Mistral Vibe CLI", "url": "https://www.anchorterminal.com/compare/earendil-pi-vs-mistral-vibe-cli" }, { "json": "https://www.anchorterminal.com/compare/earendil-pi-vs-muse-code.json", "title": "Pi vs Muse Code", "url": "https://www.anchorterminal.com/compare/earendil-pi-vs-muse-code" }, { "json": "https://www.anchorterminal.com/compare/earendil-pi-vs-openai-agents-api.json", "title": "Pi vs OpenAI Agents API", "url": "https://www.anchorterminal.com/compare/earendil-pi-vs-openai-agents-api" }, { "json": "https://www.anchorterminal.com/compare/earendil-pi-vs-openai-codex.json", "title": "Pi vs OpenAI Codex", "url": "https://www.anchorterminal.com/compare/earendil-pi-vs-openai-codex" }, { "json": "https://www.anchorterminal.com/compare/earendil-pi-vs-opencode.json", "title": "Pi vs OpenCode", "url": "https://www.anchorterminal.com/compare/earendil-pi-vs-opencode" }, { "json": "https://www.anchorterminal.com/compare/earendil-pi-vs-openhands.json", "title": "Pi vs OpenHands", "url": "https://www.anchorterminal.com/compare/earendil-pi-vs-openhands" }, { "json": "https://www.anchorterminal.com/compare/earendil-pi-vs-openmausbot.json", "title": "Pi vs OpenMausBot", "url": "https://www.anchorterminal.com/compare/earendil-pi-vs-openmausbot" }, { "json": "https://www.anchorterminal.com/compare/earendil-pi-vs-orca.json", "title": "Pi vs Orca", "url": "https://www.anchorterminal.com/compare/earendil-pi-vs-orca" }, { "json": "https://www.anchorterminal.com/compare/earendil-pi-vs-paseo.json", "title": "Pi vs Paseo", "url": "https://www.anchorterminal.com/compare/earendil-pi-vs-paseo" }, { "json": "https://www.anchorterminal.com/compare/earendil-pi-vs-prime-agent.json", "title": "Pi vs Prime Agent", "url": "https://www.anchorterminal.com/compare/earendil-pi-vs-prime-agent" }, { "json": "https://www.anchorterminal.com/compare/earendil-pi-vs-qoder-cli.json", "title": "Pi vs Qoder CLI", "url": "https://www.anchorterminal.com/compare/earendil-pi-vs-qoder-cli" }, { "json": "https://www.anchorterminal.com/compare/earendil-pi-vs-qwen-code.json", "title": "Pi vs Qwen Code", "url": "https://www.anchorterminal.com/compare/earendil-pi-vs-qwen-code" }, { "json": "https://www.anchorterminal.com/compare/earendil-pi-vs-reflection-mirror.json", "title": "Pi vs Mirror CLI", "url": "https://www.anchorterminal.com/compare/earendil-pi-vs-reflection-mirror" }, { "json": "https://www.anchorterminal.com/compare/earendil-pi-vs-rovo-dev-cli.json", "title": "Pi vs Rovo Dev CLI", "url": "https://www.anchorterminal.com/compare/earendil-pi-vs-rovo-dev-cli" }, { "json": "https://www.anchorterminal.com/compare/earendil-pi-vs-sculptor.json", "title": "Pi vs Sculptor", "url": "https://www.anchorterminal.com/compare/earendil-pi-vs-sculptor" }, { "json": "https://www.anchorterminal.com/compare/earendil-pi-vs-t3-code.json", "title": "Pi vs T3 Code", "url": "https://www.anchorterminal.com/compare/earendil-pi-vs-t3-code" }, { "json": "https://www.anchorterminal.com/compare/earendil-pi-vs-traycer.json", "title": "Pi vs Traycer", "url": "https://www.anchorterminal.com/compare/earendil-pi-vs-traycer" }, { "json": "https://www.anchorterminal.com/compare/earendil-pi-vs-unstoppable.json", "title": "Pi vs Unstoppable", "url": "https://www.anchorterminal.com/compare/earendil-pi-vs-unstoppable" }, { "json": "https://www.anchorterminal.com/compare/earendil-pi-vs-verdent.json", "title": "Pi vs Verdent", "url": "https://www.anchorterminal.com/compare/earendil-pi-vs-verdent" }, { "json": "https://www.anchorterminal.com/compare/earendil-pi-vs-vibe-trading.json", "title": "Pi vs Vibe-Trading", "url": "https://www.anchorterminal.com/compare/earendil-pi-vs-vibe-trading" }, { "json": "https://www.anchorterminal.com/compare/earendil-pi-vs-warp.json", "title": "Pi vs Warp (Warp Agent CLI and the Oz Agent API)", "url": "https://www.anchorterminal.com/compare/earendil-pi-vs-warp" }, { "json": "https://www.anchorterminal.com/compare/emdash-vs-letta.json", "title": "Emdash vs Letta", "url": "https://www.anchorterminal.com/compare/emdash-vs-letta" }, { "json": "https://www.anchorterminal.com/compare/gemini-cli-vs-letta.json", "title": "Gemini CLI vs Letta", "url": "https://www.anchorterminal.com/compare/gemini-cli-vs-letta" }, { "json": "https://www.anchorterminal.com/compare/github-copilot-cli-vs-letta.json", "title": "GitHub Copilot CLI vs Letta", "url": "https://www.anchorterminal.com/compare/github-copilot-cli-vs-letta" }, { "json": "https://www.anchorterminal.com/compare/goose-vs-letta.json", "title": "goose vs Letta", "url": "https://www.anchorterminal.com/compare/goose-vs-letta" }, { "json": "https://www.anchorterminal.com/compare/harness2-vs-letta.json", "title": "Harness² vs Letta", "url": "https://www.anchorterminal.com/compare/harness2-vs-letta" }, { "json": "https://www.anchorterminal.com/compare/harnessrouter-vs-letta.json", "title": "HarnessRouter vs Letta", "url": "https://www.anchorterminal.com/compare/harnessrouter-vs-letta" }, { "json": "https://www.anchorterminal.com/compare/jules-vs-letta.json", "title": "Jules vs Letta", "url": "https://www.anchorterminal.com/compare/jules-vs-letta" }, { "json": "https://www.anchorterminal.com/compare/junie-vs-letta.json", "title": "Junie CLI vs Letta", "url": "https://www.anchorterminal.com/compare/junie-vs-letta" }, { "json": "https://www.anchorterminal.com/compare/kilo-code-cli-vs-letta.json", "title": "Kilo Code CLI vs Letta", "url": "https://www.anchorterminal.com/compare/kilo-code-cli-vs-letta" }, { "json": "https://www.anchorterminal.com/compare/kimi-code-cli-vs-letta.json", "title": "Kimi Code CLI vs Letta", "url": "https://www.anchorterminal.com/compare/kimi-code-cli-vs-letta" }, { "json": "https://www.anchorterminal.com/compare/kiro-cli-vs-letta.json", "title": "Kiro CLI vs Letta", "url": "https://www.anchorterminal.com/compare/kiro-cli-vs-letta" }, { "json": "https://www.anchorterminal.com/compare/letta-vs-mini-swe-agent.json", "title": "Letta vs mini-swe-agent", "url": "https://www.anchorterminal.com/compare/letta-vs-mini-swe-agent" }, { "json": "https://www.anchorterminal.com/compare/letta-vs-minimax-code.json", "title": "Letta vs MiniMax Code", "url": "https://www.anchorterminal.com/compare/letta-vs-minimax-code" }, { "json": "https://www.anchorterminal.com/compare/letta-vs-mistral-vibe-cli.json", "title": "Letta vs Mistral Vibe CLI", "url": "https://www.anchorterminal.com/compare/letta-vs-mistral-vibe-cli" }, { "json": "https://www.anchorterminal.com/compare/letta-vs-muse-code.json", "title": "Letta vs Muse Code", "url": "https://www.anchorterminal.com/compare/letta-vs-muse-code" }, { "json": "https://www.anchorterminal.com/compare/letta-vs-openai-agents-api.json", "title": "Letta vs OpenAI Agents API", "url": "https://www.anchorterminal.com/compare/letta-vs-openai-agents-api" }, { "json": "https://www.anchorterminal.com/compare/letta-vs-openai-codex.json", "title": "Letta vs OpenAI Codex", "url": "https://www.anchorterminal.com/compare/letta-vs-openai-codex" }, { "json": "https://www.anchorterminal.com/compare/letta-vs-opencode.json", "title": "Letta vs OpenCode", "url": "https://www.anchorterminal.com/compare/letta-vs-opencode" }, { "json": "https://www.anchorterminal.com/compare/letta-vs-openhands.json", "title": "Letta vs OpenHands", "url": "https://www.anchorterminal.com/compare/letta-vs-openhands" }, { "json": "https://www.anchorterminal.com/compare/letta-vs-openmausbot.json", "title": "Letta vs OpenMausBot", "url": "https://www.anchorterminal.com/compare/letta-vs-openmausbot" }, { "json": "https://www.anchorterminal.com/compare/letta-vs-orca.json", "title": "Letta vs Orca", "url": "https://www.anchorterminal.com/compare/letta-vs-orca" }, { "json": "https://www.anchorterminal.com/compare/letta-vs-paseo.json", "title": "Letta vs Paseo", "url": "https://www.anchorterminal.com/compare/letta-vs-paseo" }, { "json": "https://www.anchorterminal.com/compare/letta-vs-prime-agent.json", "title": "Letta vs Prime Agent", "url": "https://www.anchorterminal.com/compare/letta-vs-prime-agent" }, { "json": "https://www.anchorterminal.com/compare/letta-vs-qoder-cli.json", "title": "Letta vs Qoder CLI", "url": "https://www.anchorterminal.com/compare/letta-vs-qoder-cli" }, { "json": "https://www.anchorterminal.com/compare/letta-vs-qwen-code.json", "title": "Letta vs Qwen Code", "url": "https://www.anchorterminal.com/compare/letta-vs-qwen-code" }, { "json": "https://www.anchorterminal.com/compare/letta-vs-reflection-mirror.json", "title": "Letta vs Mirror CLI", "url": "https://www.anchorterminal.com/compare/letta-vs-reflection-mirror" }, { "json": "https://www.anchorterminal.com/compare/letta-vs-rovo-dev-cli.json", "title": "Letta vs Rovo Dev CLI", "url": "https://www.anchorterminal.com/compare/letta-vs-rovo-dev-cli" }, { "json": "https://www.anchorterminal.com/compare/letta-vs-sculptor.json", "title": "Letta vs Sculptor", "url": "https://www.anchorterminal.com/compare/letta-vs-sculptor" }, { "json": "https://www.anchorterminal.com/compare/letta-vs-t3-code.json", "title": "Letta vs T3 Code", "url": "https://www.anchorterminal.com/compare/letta-vs-t3-code" }, { "json": "https://www.anchorterminal.com/compare/letta-vs-traycer.json", "title": "Letta vs Traycer", "url": "https://www.anchorterminal.com/compare/letta-vs-traycer" }, { "json": "https://www.anchorterminal.com/compare/letta-vs-unstoppable.json", "title": "Letta vs Unstoppable", "url": "https://www.anchorterminal.com/compare/letta-vs-unstoppable" }, { "json": "https://www.anchorterminal.com/compare/letta-vs-verdent.json", "title": "Letta vs Verdent", "url": "https://www.anchorterminal.com/compare/letta-vs-verdent" }, { "json": "https://www.anchorterminal.com/compare/letta-vs-vibe-trading.json", "title": "Letta vs Vibe-Trading", "url": "https://www.anchorterminal.com/compare/letta-vs-vibe-trading" }, { "json": "https://www.anchorterminal.com/compare/letta-vs-warp.json", "title": "Letta vs Warp (Warp Agent CLI and the Oz Agent API)", "url": "https://www.anchorterminal.com/compare/letta-vs-warp" }, { "json": "https://www.anchorterminal.com/compare/clawboo-vs-letta.json", "title": "Clawboo vs Letta", "url": "https://www.anchorterminal.com/compare/clawboo-vs-letta" }, { "json": "https://www.anchorterminal.com/compare/cli-manager-vs-letta.json", "title": "CLI Manager vs Letta", "url": "https://www.anchorterminal.com/compare/cli-manager-vs-letta" }, { "json": "https://www.anchorterminal.com/compare/harness-autonomous-vs-letta.json", "title": "Harness vs Letta", "url": "https://www.anchorterminal.com/compare/harness-autonomous-vs-letta" }, { "json": "https://www.anchorterminal.com/compare/letta-vs-paperclip.json", "title": "Letta vs Paperclip", "url": "https://www.anchorterminal.com/compare/letta-vs-paperclip" }, { "json": "https://www.anchorterminal.com/compare/letta-vs-parallax-agents.json", "title": "Letta vs Parallax", "url": "https://www.anchorterminal.com/compare/letta-vs-parallax-agents" } ], "panel": null, "scores": [ { "by": 17, "earendil-pi": 75, "edge": "earendil-pi", "key": "reliability", "letta": 58, "name": "Reliability", "weight": 16 }, { "key": "performance", "name": "Performance", "pending": true, "weight": 10 }, { "by": 14, "earendil-pi": 84, "edge": "earendil-pi", "key": "schema", "letta": 70, "name": "Schema \u0026 documentation", "weight": 13 }, { "by": 9, "earendil-pi": 76, "edge": "earendil-pi", "key": "ergonomics", "letta": 67, "name": "Agent ergonomics", "weight": 13 }, { "by": 26, "earendil-pi": 61, "edge": "earendil-pi", "key": "security", "letta": 35, "name": "Security \u0026 auth", "weight": 14 }, { "by": 0, "earendil-pi": 60, "edge": "", "key": "payments", "letta": 60, "name": "Payments \u0026 pricing", "weight": 10 }, { "key": "tasks", "name": "Task success", "pending": true, "weight": 10 }, { "by": 2, "earendil-pi": 87, "edge": "earendil-pi", "key": "maintenance", "letta": 85, "name": "Maintenance \u0026 community", "weight": 7 }, { "by": 12, "earendil-pi": 67, "edge": "earendil-pi", "key": "transparency", "letta": 55, "name": "Transparency \u0026 trust", "weight": 7 } ], "summary": "Pi scores 62.6 (B) on agent readiness against Letta's 59.7 (C), and leads in 6 of 7 scored categories. Both do agent harnesses.", "tasks": null, "tutorials": [], "verdicts": { "earendil-pi": "Four default tools, a JSONL event stream, an RPC mode and MCP tools kept out of the model's declarations by default keep context small and scripting simple. Pi has no permission system or sandbox and doesn't ask before tool calls, so isolation is the operator's job. Version 1.4.0 is dated 21 October 2026.", "letta": "Letta's open-source harness gives agents git-tracked memory blocks, skills, subagents and headless JSON runs, with a $0 plan and public per-agent API prices. It starts in the unrestricted permission mode, defaults to Letta Cloud, sends usage telemetry unless LETTA_CODE_TELEM=0 is set, and the V1 API server the comparisons describe is retired." } }, "kind": "anchor.page", "links": { "api": "https://www.anchorterminal.com/api/v1/index.json", "html": "https://www.anchorterminal.com/compare/earendil-pi-vs-letta", "json": "https://www.anchorterminal.com/compare/earendil-pi-vs-letta.json", "llms": "https://www.anchorterminal.com/llms.txt", "markdown": "https://www.anchorterminal.com/compare/earendil-pi-vs-letta.md", "mcp": "https://www.anchorterminal.com/mcp", "slim": "https://www.anchorterminal.com/compare/earendil-pi-vs-letta.min.md" }, "markdown": "Pi scores 62.6 (B) on agent readiness against Letta's 59.7 (C), and leads in 6 of 7 scored categories. Both do agent harnesses.\n\n- Pi: grade B, 62.6/100, rank #550 of 1510. Markdown https://www.anchorterminal.com/tools/earendil-pi.md · JSON https://www.anchorterminal.com/api/v1/tools/earendil-pi.json\n- Letta: grade C, 59.7/100, rank #687 of 1510. Markdown https://www.anchorterminal.com/tools/letta.md · JSON https://www.anchorterminal.com/api/v1/tools/letta.json\n- Best agent harnesses and coding agents: https://www.anchorterminal.com/best/agent-harnesses/index.md\n- All 1500 harnesses comparisons: https://www.anchorterminal.com/compare/agent-harnesses/index.md\n- Best memory layers for AI agents: https://www.anchorterminal.com/best/agent-memory/index.md\n- All 353 memory comparisons: https://www.anchorterminal.com/compare/agent-memory/index.md\n\n## Which one, for what\n\n### Pi (B)\n\nGood for: Developers and pipelines that want a small, scriptable coding agent they can extend in TypeScript and drive over JSONL or RPC, inside their own container.\n\nAhead on:\n- Reliability, 75 against 58\n- Schema \u0026 documentation, 84 against 70\n- Agent ergonomics, 76 against 67\n- Security \u0026 auth, 61 against 35\n- Transparency \u0026 trust, 67 against 55\n\nAlso in its favour:\n- No key needed to call it\n- Free to start without a card\n\nWatch for: No permission system or sandbox. Tool calls run with the user's rights and without an approval prompt\n\n### Letta (C)\n\nGood for: Long-lived coding agents and assistants that keep memory and identity across sessions and machines.\n\nAlso in its favour:\n- Runs on your own machine\n- No incidents deducted, where Pi loses 10 points for them\n\nWatch for: The default permission mode is `unrestricted`, the renamed `bypassPermissions`, so tool calls aren't confirmed unless the user picks another mode\n\n\n## Why the edge\n\n### Security \u0026 auth: Pi +26\n\n- Pi (61): Harness reading of the framework checklist, used for the harnesses in this category. 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. An anonymous install and update ping to pi.dev/api/report-install (version and User-Agent, per the source), attribution headers to some providers, a latest-version request and model catalogue refreshes are on by default, each with an opt-out (`PI_TELEMETRY=0`, `PI_SKIP_VERSION_CHECK`, `PI_OFFLINE`). Since 1.4.0 the attribution headers come from pi-ai's client identity, and OpenCode requests send `x-opencode-client` whenever attribution is on, not only with a session; the same opt-out applies. Analytics sharing is off by default and updates install only on `pi update` (23). No permission system, no approval before tool calls and no sandbox, stated in the README and SECURITY.md. Project trust gates a repository's `.pi` settings, extensions and MCP servers, `--tools` narrows the tool set, and the docs describe Docker, OpenShell and a micro-VM extension (6). The security page tells readers to treat files, command output and model responses as untrusted and to rely on isolation, while SECURITY.md puts prompt injection out of scope and context files such as AGENTS.md load whatever the trust decision (7). Sessions are JSONL files on disk with HTML export, MCP server logs go to `~/.pi/agent/mcp.log`, and the JSON stream records each tool call (11). SECURITY.md gives security@earendil.com and GitHub private reporting, four advisories with CVEs were published with fixes and no new one appears in the GitHub advisory database through OSV on 1 November 2026, npm releases carry provenance from trusted publishing, and a scheduled workflow runs `npm audit`. Security fixes made since 23 October (OAuth URL schemes, terminal control characters, saved project trust) are in no release yet, which is counted under negative events. No security.txt and no bounty found (14).\n- 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.\n\n### Reliability: Pi +17\n\n- Pi (75): Read as a local package. `@earendil-works/pi-coding-agent` 1.4.0 on npm (still the latest on 1 November 2026) with Node.js 22.19 or newer stated, install scripts for macOS, Linux and Windows, Nix and standalone binaries (20). A public CI workflow builds, checks and tests on every push to main and runs an MCP client conformance job. The run on the commit we cloned (ce950d7, 8 October 2026) passed, but eight of the last 15 runs on main, all on 7 and 8 October, failed. Run results weren't readable on 23 October, so this stands per the 8 October check (15). The repository API reported 308 open issues and pull requests against 113,417 stars on 8 October, not re-read on 23 October. Issues from new contributors are closed automatically and reviewed daily by maintainers, per CONTRIBUTING.md, so the open count understates what is reported, and we couldn't sample reply times (16). A dated changelog with Breaking Changes sections and migration steps, but breaking changes ship outside major versions. The Azure provider rename shipped in patch release 1.0.3 on 5 October 2026, minor release 1.2.0 on 12 October carried four (theme schema location, `before_agent_start`, busy-session behaviour and `pi mcp list --json` output), and 1.3.0 required `/v1` on `kimi-coding` base URL overrides under Changed. The same reading as agent-zero and mistral-vibe-cli, and these breaks also take a deduction under negative events (9). 1.4.0 on 21 October 2026, with 1.0.0 dated 1 October 2026 (15).\n- 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.\n\n### Schema \u0026 documentation: Pi +14\n\n- Pi (84): Harness reading, as for the other harnesses. JSON Schemas for settings, models, keybindings and themes ship in the package and, since 1.2.0 on 12 October 2026, at pi.dev/schemas/, and the JSON event stream and every RPC command are documented record by record, but as Markdown and TypeScript types with no machine-readable spec for the RPC protocol (18). pi.dev/llms.txt returns 404. Each docs page answers `Accept: text/markdown` with Markdown, and the docs ship inside the npm package (8). The integration page has a table saying when to use interactive, print, JSON, RPC or the SDK, and the MCP page gives a typical use for each exposure setting. 1.4.0 adds a Models Configuration reference generated from the `models.json` schema (17). Enumerated modes, thinking levels and exposure values, typed settings with defaults (13). A Python RPC client, a typed TypeScript client and about 75 example extensions, with command errors and parse errors shown as records (13). A dated changelog in the repository and at pi.dev/changelog with an RSS feed (15).\n- 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.\n\n### Transparency \u0026 trust: Pi +12\n\n- Pi (67): MIT (30). No privacy policy for pi.dev or the CLI was found (pi.dev/privacy, earendil.com/privacy and radius.earendil.com/privacy return 404 on 23 October 2026, and pi.dev/privacy and pi.dev/terms again on 1 November). The docs say where sessions and credentials are stored and what `/share` and `/bug` upload. The Radius alpha terms of 1 September 2026 name Earendil Works Co. and refer to a Privacy Notice we couldn't locate (10). Breaking changes are listed per release with migration steps, with no deprecation policy or notice period found. Pi Durable's README says its API changes without notice between releases (8). Install telemetry and the version check are documented in the settings and environment-variable pages with opt-outs, though the docs don't list the fields sent (16).\n- 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.\n\n### Agent ergonomics: Pi +9\n\n- Pi (76): Harness reading of the framework line, scored on what an agent or pipeline driving it has to supply. Four default tools (read, bash, edit, write) and a short system prompt. MCP tools default to `codemode` exposure, which keeps them out of the model's tool declarations, and `tool_search` loads deferred ones on demand (23). Automatic compaction, agent-level retry with three attempts and exponential backoff, and truncated tool output saved to a file. We found no turn or step limit in the CLI or settings reference (13). `--mode json` streams JSONL events ending in `agent_settled` and `--mode rpc` returns `success: false` with an error string. Print mode exits nonzero on a failed response, JSON mode doesn't (16). Sessions are stored as trees and continue, fork or take a fixed ID with `--continue`, `--fork` and `--session-id`. File changes have no built-in undo, and a git checkpoint is an example extension (14). It needs a provider key or subscription login before the first run, and the SDK is TypeScript only, with RPC for other languages (10).\n- 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.\n\n## Score by category\n\n| Category | Weight | Pi | Letta | Edge |\n| --- | --- | --- | --- | --- |\n| Reliability | 16% (20 this run) | 75 | 58 | Pi +17 |\n| Performance | 10%, pending | pending | pending | not scored in this run |\n| Schema \u0026 documentation | 13% (16.2 this run) | 84 | 70 | Pi +14 |\n| Agent ergonomics | 13% (16.2 this run) | 76 | 67 | Pi +9 |\n| Security \u0026 auth | 14% (17.5 this run) | 61 | 35 | Pi +26 |\n| Payments \u0026 pricing | 10% (12.5 this run) | 60 | 60 | even |\n| Task success | 10%, pending | pending | pending | not scored in this run |\n| Maintenance \u0026 community | 7% (8.8 this run) | 87 | 85 | Pi +2 |\n| Transparency \u0026 trust | 7% (8.8 this run) | 67 | 55 | Pi +12 |\n| Negative events | ≤15 | -10 | 0 | |\n| **Total** | | **62.6 · B** | **59.7 · C** | |\n\n## Facts side by side\n\n| Fact | Pi | Letta |\n| --- | --- | --- |\n| Kind | Agent harness | Agent harness |\n| Vendor | Earendil | Letta |\n| Hosted endpoint | no (local only) | no (local only) |\n| Transports | | stdio |\n| Auth | None | OAuth or key |\n| Pricing | Free | Freemium |\n| x402 | no | no |\n| Licence | MIT | Apache-2.0 |\n| Read-only variant documented | no | no |\n| llms.txt | no | yes |\n| Last release | 2026-10-21 | 2026-11-06 |\n| Terms last updated | no document linked | no date given |\n| Privacy policy last updated | no document linked | no date given |\n| Customer content may train models | not read yet | not found in the text |\n| Terms restrict automated access | not read yet | not found in the text |\n| Terms restrict benchmarking | not read yet | not found in the text |\n| Terms or service can change without notice | not read yet | not found in the text |\n| Arbitration or class-action waiver | not read yet | yes |\n| Popularity | 113k stars, 5.2M npm/wk | 3.8k stars, 86k npm/wk, 2.2k PyPI/wk |\n| Agent reviews | 3.3/5 (4) | none |\n\n## How the scores have moved\n\n### Pi\n\n- -6.0 on 1 November 2026: negative event\n- +0.2 on 27 October 2026: checklist\n\n### Letta\n\nNo score change since it was listed.\n\n## Verdicts\n\n**Pi.** Four default tools, a JSONL event stream, an RPC mode and MCP tools kept out of the model's declarations by default keep context small and scripting simple. Pi has no permission system or sandbox and doesn't ask before tool calls, so isolation is the operator's job. Version 1.4.0 is dated 21 October 2026.\n\n**Letta.** Letta's open-source harness gives agents git-tracked memory blocks, skills, subagents and headless JSON runs, with a $0 plan and public per-agent API prices. It starts in the unrestricted permission mode, defaults to Letta Cloud, sends usage telemetry unless LETTA_CODE_TELEM=0 is set, and the V1 API server the comparisons describe is retired.\n\n## Before you call either\n\n### Pi\n\n1. Run Pi inside a container or VM for unattended work. It has no sandbox and doesn't ask before running shell commands\n2. Use `pi --mode json` and wait for `agent_settled`. A failed response doesn't set a nonzero exit code in JSON mode\n3. Split the JSONL stream on LF only. Node's `readline` also splits on U+2028 and U+2029, which are valid inside JSON strings\n4. Pass `--no-approve` or `--approve` in scripts to make the project trust decision explicit\n5. Set `PI_TELEMETRY=0` and `PI_SKIP_VERSION_CHECK=1`, or `PI_OFFLINE=1`, to stop the default requests to pi.dev\n\n### Letta\n\n1. Start headless runs with an explicit permission mode such as `standard` or `strict`; the default auto-approves tools\n2. Pass `--backend local` for work that must stay on the machine, since Letta Cloud is the default\n3. Set LETTA_CODE_TELEM=0 in unattended runs if usage events must not be sent\n4. Use `letta -p --output-format json` for scripted runs and parse the JSON, not the terminal output\n5. Don't plan on the retired V1 REST server or `.af` AgentFile import; both are gone\n\n## Questions\n\n### Which is better for AI agents, Pi or Letta?\n\nPi scores 62.6 (B) on agent readiness against Letta's 59.7 (C), and leads in 6 of 7 scored categories.\n\n### Are Pi and Letta open source?\n\nYes. Pi is open source (MIT). Letta is open source (Apache-2.0).\n\n\n## For agents\n\n- This comparison as JSON: https://www.anchorterminal.com/compare/earendil-pi-vs-letta.json, and with the fewest tokens: https://www.anchorterminal.com/compare/earendil-pi-vs-letta.min.md\n- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {\"a\": \"earendil-pi\", \"b\": \"letta\"}`. From a terminal: `anchor compare earendil-pi letta`\n- Each listing in full: https://www.anchorterminal.com/api/v1/tools/earendil-pi.json and https://www.anchorterminal.com/api/v1/tools/letta.json\n\n## Other comparisons with Pi or Letta\n\n- [Agent Zero vs Pi](https://www.anchorterminal.com/compare/agent-zero-vs-earendil-pi.md)\n- [Agent Zero vs Letta](https://www.anchorterminal.com/compare/agent-zero-vs-letta.md)\n- [Aider vs Pi](https://www.anchorterminal.com/compare/aider-vs-earendil-pi.md)\n- [Aider vs Letta](https://www.anchorterminal.com/compare/aider-vs-letta.md)\n- [Amp vs Pi](https://www.anchorterminal.com/compare/amp-vs-earendil-pi.md)\n- [Amp vs Letta](https://www.anchorterminal.com/compare/amp-vs-letta.md)\n- [Antigravity CLI vs Pi](https://www.anchorterminal.com/compare/antigravity-cli-vs-earendil-pi.md)\n- [Antigravity CLI vs Letta](https://www.anchorterminal.com/compare/antigravity-cli-vs-letta.md)\n- [Auggie CLI vs Pi](https://www.anchorterminal.com/compare/auggie-vs-earendil-pi.md)\n- [Auggie CLI vs Letta](https://www.anchorterminal.com/compare/auggie-vs-letta.md)\n- [AXLR vs Pi](https://www.anchorterminal.com/compare/axlr-vs-earendil-pi.md)\n- [AXLR vs Letta](https://www.anchorterminal.com/compare/axlr-vs-letta.md)\n- [Claude Code vs Pi](https://www.anchorterminal.com/compare/claude-code-vs-earendil-pi.md)\n- [Claude Code vs Letta](https://www.anchorterminal.com/compare/claude-code-vs-letta.md)\n- [Cline vs Pi](https://www.anchorterminal.com/compare/cline-vs-earendil-pi.md)\n- [Cline vs Letta](https://www.anchorterminal.com/compare/cline-vs-letta.md)\n- [Conductor vs Pi](https://www.anchorterminal.com/compare/conductor-vs-earendil-pi.md)\n- [Conductor vs Letta](https://www.anchorterminal.com/compare/conductor-vs-letta.md)\n- [Crush vs Pi](https://www.anchorterminal.com/compare/crush-vs-earendil-pi.md)\n- [Crush vs Letta](https://www.anchorterminal.com/compare/crush-vs-letta.md)\n- [Cursor CLI vs Pi](https://www.anchorterminal.com/compare/cursor-cli-vs-earendil-pi.md)\n- [Cursor CLI vs Letta](https://www.anchorterminal.com/compare/cursor-cli-vs-letta.md)\n- [DeepSeek Harness (dsh) vs Pi](https://www.anchorterminal.com/compare/deepseek-harness-vs-earendil-pi.md)\n- [DeepSeek Harness (dsh) vs Letta](https://www.anchorterminal.com/compare/deepseek-harness-vs-letta.md)\n- [dsh-superagent (DeepSeek) vs Pi](https://www.anchorterminal.com/compare/deepseek-superagent-vs-earendil-pi.md)\n- [dsh-superagent (DeepSeek) vs Letta](https://www.anchorterminal.com/compare/deepseek-superagent-vs-letta.md)\n- [Devin vs Pi](https://www.anchorterminal.com/compare/devin-vs-earendil-pi.md)\n- [Devin vs Letta](https://www.anchorterminal.com/compare/devin-vs-letta.md)\n- [Droid CLI vs Pi](https://www.anchorterminal.com/compare/droid-cli-vs-earendil-pi.md)\n- [Droid CLI vs Letta](https://www.anchorterminal.com/compare/droid-cli-vs-letta.md)\n- [Pi vs Emdash](https://www.anchorterminal.com/compare/earendil-pi-vs-emdash.md)\n- [Pi vs Gemini CLI](https://www.anchorterminal.com/compare/earendil-pi-vs-gemini-cli.md)\n- [Pi vs GitHub Copilot CLI](https://www.anchorterminal.com/compare/earendil-pi-vs-github-copilot-cli.md)\n- [Pi vs goose](https://www.anchorterminal.com/compare/earendil-pi-vs-goose.md)\n- [Pi vs Harness²](https://www.anchorterminal.com/compare/earendil-pi-vs-harness2.md)\n- [Pi vs HarnessRouter](https://www.anchorterminal.com/compare/earendil-pi-vs-harnessrouter.md)\n- [Pi vs Jules](https://www.anchorterminal.com/compare/earendil-pi-vs-jules.md)\n- [Pi vs Junie CLI](https://www.anchorterminal.com/compare/earendil-pi-vs-junie.md)\n- [Pi vs Kilo Code CLI](https://www.anchorterminal.com/compare/earendil-pi-vs-kilo-code-cli.md)\n- [Pi vs Kimi Code CLI](https://www.anchorterminal.com/compare/earendil-pi-vs-kimi-code-cli.md)\n- [Pi vs Kiro CLI](https://www.anchorterminal.com/compare/earendil-pi-vs-kiro-cli.md)\n- [Pi vs mini-swe-agent](https://www.anchorterminal.com/compare/earendil-pi-vs-mini-swe-agent.md)\n- [Pi vs MiniMax Code](https://www.anchorterminal.com/compare/earendil-pi-vs-minimax-code.md)\n- [Pi vs Mistral Vibe CLI](https://www.anchorterminal.com/compare/earendil-pi-vs-mistral-vibe-cli.md)\n- [Pi vs Muse Code](https://www.anchorterminal.com/compare/earendil-pi-vs-muse-code.md)\n- [Pi vs OpenAI Agents API](https://www.anchorterminal.com/compare/earendil-pi-vs-openai-agents-api.md)\n- [Pi vs OpenAI Codex](https://www.anchorterminal.com/compare/earendil-pi-vs-openai-codex.md)\n- [Pi vs OpenCode](https://www.anchorterminal.com/compare/earendil-pi-vs-opencode.md)\n- [Pi vs OpenHands](https://www.anchorterminal.com/compare/earendil-pi-vs-openhands.md)\n- [Pi vs OpenMausBot](https://www.anchorterminal.com/compare/earendil-pi-vs-openmausbot.md)\n- [Pi vs Orca](https://www.anchorterminal.com/compare/earendil-pi-vs-orca.md)\n- [Pi vs Paseo](https://www.anchorterminal.com/compare/earendil-pi-vs-paseo.md)\n- [Pi vs Prime Agent](https://www.anchorterminal.com/compare/earendil-pi-vs-prime-agent.md)\n- [Pi vs Qoder CLI](https://www.anchorterminal.com/compare/earendil-pi-vs-qoder-cli.md)\n- [Pi vs Qwen Code](https://www.anchorterminal.com/compare/earendil-pi-vs-qwen-code.md)\n- [Pi vs Mirror CLI](https://www.anchorterminal.com/compare/earendil-pi-vs-reflection-mirror.md)\n- [Pi vs Rovo Dev CLI](https://www.anchorterminal.com/compare/earendil-pi-vs-rovo-dev-cli.md)\n- [Pi vs Sculptor](https://www.anchorterminal.com/compare/earendil-pi-vs-sculptor.md)\n- [Pi vs T3 Code](https://www.anchorterminal.com/compare/earendil-pi-vs-t3-code.md)\n- [Pi vs Traycer](https://www.anchorterminal.com/compare/earendil-pi-vs-traycer.md)\n- [Pi vs Unstoppable](https://www.anchorterminal.com/compare/earendil-pi-vs-unstoppable.md)\n- [Pi vs Verdent](https://www.anchorterminal.com/compare/earendil-pi-vs-verdent.md)\n- [Pi vs Vibe-Trading](https://www.anchorterminal.com/compare/earendil-pi-vs-vibe-trading.md)\n- [Pi vs Warp (Warp Agent CLI and the Oz Agent API)](https://www.anchorterminal.com/compare/earendil-pi-vs-warp.md)\n- [Emdash vs Letta](https://www.anchorterminal.com/compare/emdash-vs-letta.md)\n- [Gemini CLI vs Letta](https://www.anchorterminal.com/compare/gemini-cli-vs-letta.md)\n- [GitHub Copilot CLI vs Letta](https://www.anchorterminal.com/compare/github-copilot-cli-vs-letta.md)\n- [goose vs Letta](https://www.anchorterminal.com/compare/goose-vs-letta.md)\n- [Harness² vs Letta](https://www.anchorterminal.com/compare/harness2-vs-letta.md)\n- [HarnessRouter vs Letta](https://www.anchorterminal.com/compare/harnessrouter-vs-letta.md)\n- [Jules vs Letta](https://www.anchorterminal.com/compare/jules-vs-letta.md)\n- [Junie CLI vs Letta](https://www.anchorterminal.com/compare/junie-vs-letta.md)\n- [Kilo Code CLI vs Letta](https://www.anchorterminal.com/compare/kilo-code-cli-vs-letta.md)\n- [Kimi Code CLI vs Letta](https://www.anchorterminal.com/compare/kimi-code-cli-vs-letta.md)\n- [Kiro CLI vs Letta](https://www.anchorterminal.com/compare/kiro-cli-vs-letta.md)\n- [Letta vs mini-swe-agent](https://www.anchorterminal.com/compare/letta-vs-mini-swe-agent.md)\n- [Letta vs MiniMax Code](https://www.anchorterminal.com/compare/letta-vs-minimax-code.md)\n- [Letta vs Mistral Vibe CLI](https://www.anchorterminal.com/compare/letta-vs-mistral-vibe-cli.md)\n- [Letta vs Muse Code](https://www.anchorterminal.com/compare/letta-vs-muse-code.md)\n- [Letta vs OpenAI Agents API](https://www.anchorterminal.com/compare/letta-vs-openai-agents-api.md)\n- [Letta vs OpenAI Codex](https://www.anchorterminal.com/compare/letta-vs-openai-codex.md)\n- [Letta vs OpenCode](https://www.anchorterminal.com/compare/letta-vs-opencode.md)\n- [Letta vs OpenHands](https://www.anchorterminal.com/compare/letta-vs-openhands.md)\n- [Letta vs OpenMausBot](https://www.anchorterminal.com/compare/letta-vs-openmausbot.md)\n- [Letta vs Orca](https://www.anchorterminal.com/compare/letta-vs-orca.md)\n- [Letta vs Paseo](https://www.anchorterminal.com/compare/letta-vs-paseo.md)\n- [Letta vs Prime Agent](https://www.anchorterminal.com/compare/letta-vs-prime-agent.md)\n- [Letta vs Qoder CLI](https://www.anchorterminal.com/compare/letta-vs-qoder-cli.md)\n- [Letta vs Qwen Code](https://www.anchorterminal.com/compare/letta-vs-qwen-code.md)\n- [Letta vs Mirror CLI](https://www.anchorterminal.com/compare/letta-vs-reflection-mirror.md)\n- [Letta vs Rovo Dev CLI](https://www.anchorterminal.com/compare/letta-vs-rovo-dev-cli.md)\n- [Letta vs Sculptor](https://www.anchorterminal.com/compare/letta-vs-sculptor.md)\n- [Letta vs T3 Code](https://www.anchorterminal.com/compare/letta-vs-t3-code.md)\n- [Letta vs Traycer](https://www.anchorterminal.com/compare/letta-vs-traycer.md)\n- [Letta vs Unstoppable](https://www.anchorterminal.com/compare/letta-vs-unstoppable.md)\n- [Letta vs Verdent](https://www.anchorterminal.com/compare/letta-vs-verdent.md)\n- [Letta vs Vibe-Trading](https://www.anchorterminal.com/compare/letta-vs-vibe-trading.md)\n- [Letta vs Warp (Warp Agent CLI and the Oz Agent API)](https://www.anchorterminal.com/compare/letta-vs-warp.md)\n- [Clawboo vs Letta](https://www.anchorterminal.com/compare/clawboo-vs-letta.md)\n- [CLI Manager vs Letta](https://www.anchorterminal.com/compare/cli-manager-vs-letta.md)\n- [Harness vs Letta](https://www.anchorterminal.com/compare/harness-autonomous-vs-letta.md)\n- [Letta vs Paperclip](https://www.anchorterminal.com/compare/letta-vs-paperclip.md)\n- [Letta vs Parallax](https://www.anchorterminal.com/compare/letta-vs-parallax-agents.md)\n", "meta": { "attribution": "Anchor Terminal (https://www.anchorterminal.com)", "attributionRequired": true, "credit": "CC BY 4.0, credit Anchor Terminal and link the page or API address you took it from (https://www.anchorterminal.com/terms/#data)", "docs": "https://www.anchorterminal.com/docs/", "generatedAt": "2026-11-07", "license": "CC-BY-4.0", "method": "https://www.anchorterminal.com/benchmark/", "methodology": "0.7", "openapi": "https://www.anchorterminal.com/openapi.json", "preview": false, "run": "2026-10-01", "runLabel": "October 2026 research run", "terms": "https://www.anchorterminal.com/terms/#data" }, "page": { "breadcrumbs": [ { "name": "Home", "url": "https://www.anchorterminal.com/" }, { "name": "Compare", "url": "https://www.anchorterminal.com/compare/" }, { "name": "Pi vs Letta", "url": "" } ], "description": "Pi scores 62.6 (B) to Letta's 59.7 (C) for agent harnesses. 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