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        "name": "Sequential Thinking (MCP reference server)",
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        "summary": "Single-tool reference server (`sequentialthinking`) that structures step-by-step reasoning with numbered thoughts, revisions and branches; no external calls.",
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        "auth": "none",
        "authNotes": "Local process; DISABLE_THOUGHT_LOGGING=true silences thought logging.",
        "pricing": "free",
        "pricingNotes": "Open source.",
        "priceSummary": "Free · OSS",
        "where": "local",
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        "graded": true,
        "disclosure": "MCP started at Anthropic, which makes the Claude models our research agents and review panel run on (Anthropic donated it to the Agentic AI Foundation, a directed fund under the Linux Foundation, in December 2025), and this server is graded by the same checklist as every other listing.",
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            "payments": 60,
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            "schema": 73,
            "security": 64,
            "transparency": 74
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            "confidence": "medium",
            "date": "2026-10-01"
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          "verdict": "The server needs no network access or credentials and stores only in-memory history. Each reasoning step requires a separate tool call.",
          "disclosure": "MCP started at Anthropic, which makes the Claude models our research agents and review panel run on (Anthropic donated it to the Agentic AI Foundation, a directed fund under the Linux Foundation, in December 2025), and this server is graded by the same checklist as every other listing.",
          "strengths": [
            "No network access, no credentials and no side effects beyond an in-memory history",
            "Revision and branch fields give a model a structured place to backtrack",
            "Typed input and output schemas with readOnly and non-destructive hints",
            "Thought logging to stderr can be turned off with `DISABLE_THOUGHT_LOGGING=true`"
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            "Only 2026.7.4 and 2026.8.31 were published in 2026, and the latest doesn't declare its zod dependency",
            "History is shared across the whole process, so separate problems in one session run together",
            "README says `sequential_thinking` but the registered name is `sequentialthinking`",
            "The maintainers call it a reference implementation, not production-ready"
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            "Call it as `sequentialthinking`, not `sequential_thinking`",
            "Set `totalThoughts` low and raise it only when a revision needs room",
            "Restart the server between unrelated problems, or ignore `thoughtHistoryLength` and `branches` from earlier work",
            "Skip it when the host model already has extended thinking"
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            "security": 64,
            "transparency": 73
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          "memory-reference-server",
          "postgres-reference-server-archived"
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          "legalEntity": "Model Context Protocol, a Series of LF Projects, LLC",
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          "domainRegistered": "2024-11-18",
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  "markdown": "Tools that make no external calls and exist to structure an agent's own thinking.\n\n- Tools ranked: 1 · agent-ready (BB or better): 0 · accept x402: 0 · hosted endpoints: 0 · desk reviews by the panel: 2\n- JSON: https://www.anchorterminal.com/api/v1/tools.json (list) · https://www.anchorterminal.com/api/v1/rankings.json (ranked) · https://www.anchorterminal.com/api/v1/x402.json (payable) · https://www.anchorterminal.com/api/v1/capabilities.json (by capability)\n- Grades run AA, A, BB, B, C, D, E, F · methodology: https://www.anchorterminal.com/benchmark/\n\n- Capabilities in this category: reasoning.scaffold\n- https://letme.dev/reasoning.scaffold picks the top-graded tool in this list and says how to call it direct; calling through letme comes later (https://www.anchorterminal.com/letme/index.md)\n\n## Ranking\n\n| # | Tool | Vendor | Kind | Category | Grade | Score | Confidence | x402 | Auth | Where | Reviews | Page |\n| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |\n| 214 | Sequential Thinking (MCP reference server) | MCP project (reference servers) | MCP server | Reasoning | B | 62.7 | medium | no | None | local | 3/5 (2) | https://www.anchorterminal.com/tools/sequential-thinking-reference-server.md |\n\nScores are from public evidence against the published checklist (https://www.anchorterminal.com/benchmark/), with Performance and Task success pending. p95 latency and context cost come from our probes, which haven't run yet.\n\n## Summaries\n\n### 214. Sequential Thinking (MCP reference server), B (62.7)\n\nSingle-tool reference server (`sequentialthinking`) that structures step-by-step reasoning with numbered thoughts, revisions and branches; no external calls. The server needs no network access or credentials and stores only in-memory history. Each reasoning step requires a separate tool call.\n\n- Page: https://www.anchorterminal.com/tools/sequential-thinking-reference-server · Markdown: https://www.anchorterminal.com/tools/sequential-thinking-reference-server.md · JSON: https://www.anchorterminal.com/api/v1/tools/sequential-thinking-reference-server.json\n- Capabilities: reasoning.scaffold\n\n",
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