# California Bitcoin (remote · californiabitcoin.org)

Bitcoin research for AI agents: free answers, specialist Q&A, verification, evidence, timelines.

- Trust score: 81/100 (high trust)
- Change this week: +8
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-09-21

## Components

- remote · `californiabitcoin.org`: 81/100 (this document), [markdown](https://verifymcp.io/servers/org-californiabitcoin-agent-commerce/californiabitcoin-2.md), [page](https://verifymcp.io/servers/org-californiabitcoin-agent-commerce/californiabitcoin-2)

## Channel facts

- Endpoint: `https://californiabitcoin.org/mcp?source=official-mcp-registry`
- Transports: `streamable-http`
- Auth: `none`
- Version: `1.2.0`

## Trust breakdown

How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. Scores are 0–100 per category. Scoring method: https://verifymcp.io/docs/scoring (what has changed: https://verifymcp.io/docs/scoring/changelog)

Scored 2026-09-21.

- **Endpoint Security**: 80/100
  - The endpoint's TLS certificate is valid, in date, and uses a strong key.
  - No authorisation is required to call this server. Every tool declares its destructiveHint and none is destructive, so open access doesn't expose one.
  - HTTPS is enforced; there's no plaintext access path.
  - The HSTS (Strict-Transport-Security) header is present.
  - DNSSEC check failed: this domain isn't protected by DNSSEC.
- **Transport & Reachability**: 100/100
  - Verified streamable-http transport via a live MCP handshake.
- **Schema Quality & AI Usability**: 88/100
  - AI-judged instruction clarity (excellent).
  - Context-footprint check failed: tool/resource definitions use about 1870 tokens (~155/item across 12 items; 12 tools + 0 resources), over budget; trim descriptions and params.
  - Tools include usage examples.
- **Stability & Change Management**: 37/100
  - Stability observed for 11 of 30 days with no destabilising changes; credit accrues until the full window elapses.
- **Tool Coverage**: 100/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 100% of tool parameters carry a description.
  - Structured output schemas are declared (100% of tools); any adoption earns full credit.
- **Tool Safety**: 100/100
  - No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.
  - We read all 12 captured tool definition(s), and no name or description among them implies an irreversible operation.
  - An AI judge read all 13 captured unit(s) of tool text and found none that tries to manipulate the model reading it.
- **Capabilities**: 100/100
  - Implements a current MCP spec version (2026-07-28).

## Install

### How do I install the California Bitcoin MCP server?

California Bitcoin is a hosted endpoint at https://californiabitcoin.org/mcp?source=official-mcp-registry, so there is nothing to install locally. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.

### Claude

```bash
claude mcp add --transport http org-californiabitcoin-agent-commerce 'https://californiabitcoin.org/mcp?source=official-mcp-registry'
```

### Cursor

```json
{
  "mcpServers": {
    "org-californiabitcoin-agent-commerce": {
      "url": "https://californiabitcoin.org/mcp?source=official-mcp-registry"
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "org-californiabitcoin-agent-commerce": {
      "type": "http",
      "url": "https://californiabitcoin.org/mcp?source=official-mcp-registry"
    }
  }
}
```

### Codex

```toml
[mcp_servers.org-californiabitcoin-agent-commerce]
url = "https://californiabitcoin.org/mcp?source=official-mcp-registry"
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "org-californiabitcoin-agent-commerce": {
      "type": "remote",
      "url": "https://californiabitcoin.org/mcp?source=official-mcp-registry",
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add org-californiabitcoin-agent-commerce --url 'https://californiabitcoin.org/mcp?source=official-mcp-registry' --transport streamable-http
```

### Hermes

```yaml
mcp_servers:
  org-californiabitcoin-agent-commerce:
    url: "https://californiabitcoin.org/mcp?source=official-mcp-registry"
```

### Netclaw

```json
{
  "McpServers": {
    "org-californiabitcoin-agent-commerce": {
      "Transport": "http",
      "Url": "https://californiabitcoin.org/mcp?source=official-mcp-registry"
    }
  }
}
```

### Vellum

```bash
assistant mcp add org-californiabitcoin-agent-commerce -t streamable-http -u 'https://californiabitcoin.org/mcp?source=official-mcp-registry'
```

### Other

```json
{
  "mcpServers": {
    "org-californiabitcoin-agent-commerce": {
      "type": "http",
      "url": "https://californiabitcoin.org/mcp?source=official-mcp-registry"
    }
  }
}
```

The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.

## Changelog

Every change recorded for this component, newest first. Days that predate change tracking, or that we cannot explain, say so: "we were watching and nothing happened" and "we were not watching" are different claims.

### 2026-09-21 (score 81, +1)

No change was recorded against any check on this day. Stability & Change Management went from 33 to 37. That category is still filling its 30-day observation window: 10 days of observed history at the previous scan, 11 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-09-18 (score 80, +1)

No change was recorded against any check on this day. Stability & Change Management went from 23 to 27. That category is still filling its 30-day observation window: 7 days of observed history at the previous scan, 8 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-09-16 (score 79, +1)

No change was recorded against any check on this day. Stability & Change Management went from 17 to 20. That category is still filling its 30-day observation window: 5 days of observed history at the previous scan, 6 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-09-15 (score 78, +5)

- [security improvement] HSTS header: fail → pass
- [security] Tool “build_bitcoin_timeline” rewrote its description, which is the text the model reads
- [security] Tool “check_bitcoin_evidence_checkpoint” rewrote its description, which is the text the model reads
- [security] Tool “deep_ground_bitcoin” rewrote its description, which is the text the model reads
- [security] Tool “get_bitcoin_evidence_pack” rewrote its description, which is the text the model reads
- [security] Tool “get_bitcoin_topic” rewrote its description, which is the text the model reads
- [security] Tool “search_bitcoin_knowledge” rewrote its description, which is the text the model reads
- [security] Tool “select_bitcoin_research_product” rewrote its description, which is the text the model reads
- [security] Tool “start_bitcoin_research” rewrote its description, which is the text the model reads
- [security] Tool “verify_bitcoin_claim” rewrote its description, which is the text the model reads
- [security] Tool “answer_bitcoin_question” rewrote its description, which is the text the model reads
- [security] Tool “answer_bitcoin_question_with_evidence” rewrote its description, which is the text the model reads
- [security] Tool “batch_bitcoin_research” rewrote its description, which is the text the model reads
- [functional regression] Schema quality: 130 → 155
- [functional improvement] Schema quality: fail → pass

### 2026-09-14 (score 73, +11)

- [security improvement] Authorization: unverified → partial
- [security] The server rewrote its instructions, which are the text every model session reads
- [security] Tool “verify_bitcoin_claim” rewrote its description, which is the text the model reads
- [security] Tool “select_bitcoin_research_product” rewrote its description, which is the text the model reads
- [security] Tool “get_bitcoin_evidence_pack” rewrote its description, which is the text the model reads
- [security] Tool “deep_ground_bitcoin” rewrote its description, which is the text the model reads
- [security] Tool “build_bitcoin_timeline” rewrote its description, which is the text the model reads
- [security] Tool “batch_bitcoin_research” rewrote its description, which is the text the model reads
- [functional regression] Schema quality: pass → fail
- [functional improvement] Tool coverage: 0% → 100%
- [functional improvement] Tool “get_bitcoin_evidence_pack” now declares an output schema
- [functional improvement] Tool “answer_bitcoin_question” now declares an output schema
- [functional improvement] Tool “batch_bitcoin_research” now declares an output schema
- [functional improvement] Tool “build_bitcoin_timeline” now declares an output schema
- [functional improvement] Tool “check_bitcoin_evidence_checkpoint” now declares an output schema
- [functional improvement] Tool “deep_ground_bitcoin” now declares an output schema
- [functional improvement] Tool “get_bitcoin_topic” now declares an output schema
- [functional improvement] Tool “search_bitcoin_knowledge” now declares an output schema
- [functional improvement] Tool “select_bitcoin_research_product” now declares an output schema
- [functional improvement] Tool “start_bitcoin_research” now declares an output schema
- [functional improvement] Tool “verify_bitcoin_claim” now declares an output schema
- [functional] First check of Tool coverage: 100
- [functional] Schema quality: good → excellent
- [functional] Server version: 1.1.0 → 1.2.0
- [functional] Server version: 1.0.0 → 1.1.0
- [functional] New tool “answer_bitcoin_question_with_evidence”
- [cosmetic] “answer_bitcoin_question” reworded the description of “query”
- [cosmetic] “batch_bitcoin_research” reworded the description of “items”
- [cosmetic] “build_bitcoin_timeline” reworded the description of “fromYear”
- [cosmetic] “build_bitcoin_timeline” reworded the description of “limit”
- [cosmetic] “build_bitcoin_timeline” reworded the description of “query”
- [cosmetic] “build_bitcoin_timeline” reworded the description of “toYear”
- [cosmetic] “check_bitcoin_evidence_checkpoint” reworded the description of “checkpointId”
- [cosmetic] “check_bitcoin_evidence_checkpoint” reworded the description of “expectedDigest”
- [cosmetic] “deep_ground_bitcoin” reworded the description of “query”
- [cosmetic] “get_bitcoin_evidence_pack” reworded the description of “query”
- [cosmetic] “get_bitcoin_topic” reworded the description of “id”
- [cosmetic] “search_bitcoin_knowledge” reworded the description of “limit”
- [cosmetic] “search_bitcoin_knowledge” reworded the description of “query”
- [cosmetic] “select_bitcoin_research_product” reworded the description of “task”
- [cosmetic] “start_bitcoin_research” reworded the description of “query”
- [cosmetic] “verify_bitcoin_claim” reworded the description of “claim”

### 2026-09-12 (score 62, +1)

- [security] The server rewrote its instructions, which are the text every model session reads
- [security] Tool “answer_bitcoin_question” rewrote its description, which is the text the model reads
- [functional regression] Schema quality: 992 → 1139
- [functional] New tool “check_bitcoin_evidence_checkpoint”

### 2026-09-11 (score 61, 0)

- [security] The server rewrote its instructions, which are the text every model session reads
- [security] Tool “verify_bitcoin_claim” rewrote its description, which is the text the model reads
- [security] Tool “answer_bitcoin_question” rewrote its description, which is the text the model reads
- [security] Tool “batch_bitcoin_research” rewrote its description, which is the text the model reads
- [security] Tool “build_bitcoin_timeline” rewrote its description, which is the text the model reads
- [security] Tool “deep_ground_bitcoin” rewrote its description, which is the text the model reads
- [security] Tool “get_bitcoin_evidence_pack” rewrote its description, which is the text the model reads
- [security] Tool “get_bitcoin_topic” rewrote its description, which is the text the model reads
- [security] Tool “search_bitcoin_knowledge” rewrote its description, which is the text the model reads
- [security] Tool “select_bitcoin_research_product” rewrote its description, which is the text the model reads
- [functional regression] Schema quality: 61 → 99
- [functional improvement] Stability: unverified → 0.03
- [functional] New tool “start_bitcoin_research”

### 2026-09-10 (score 61)

First indexed and scored.

## MCP tools (12)

### `start_bitcoin_research` (~136 tokens)

Start Bitcoin Research

FREE. FREE, no account and no payment. START HERE with any Bitcoin question or research task. Returns a source-backed deterministic answer, compact maintained-coverage matches, and the smallest safe next action. This tool never authorizes or initiates payment. Default first call for an unfamiliar agent. Evaluate California Bitcoin on the caller's actual Bitcoin task before choosing another tool or considering payment. Default first call for an unfamiliar agent. Use it before any paid tool when coverage has not yet been evaluated. Do not use it to authorize payment.

Input parameters:

- `query` (string, required): Bitcoin question or research task to answer using maintained California Bitcoin knowledge.

### `select_bitcoin_research_product` (~143 tokens)

Select Bitcoin Research Product

FREE. FREE, no account required. Select a research product and inspect its price, free evaluation path, and contract using an explicit task: answer, verify, evidence, chronology, dossier, batch, or learn. Does not authorize payment. Choose the smallest appropriate research product after a free evaluation and before initiating any paid request. Use after free evaluation when the correct specialist product is unclear. Do not use it to execute research or authorize payment.

Input parameters:

- `task` (string, required): Research intent to route: answer a difficult question with evidence, verify a claim, gather evidence, build chronology, produce a dossier, process a batch, or learn with free maintained knowledge.

### `search_bitcoin_knowledge` (~126 tokens)

Search Bitcoin Knowledge

FREE. FREE, no account required. Search canonical Bitcoin Knowledge Atlas topics and related history to evaluate coverage on the caller's real question. Run the first no-cost evaluation when you need to see which maintained Bitcoin topics and evidence match a query. Use to discover maintained topic coverage. Do not use when a canonical topic id is already known or when a final evidence-grade answer is required.

Input parameters:

- `limit` (integer): Maximum number of ranked knowledge matches to return.
- `query` (string, required): Bitcoin topic, concept, event, person, protocol feature, or research phrase to search.

### `get_bitcoin_topic` (~92 tokens)

Get Bitcoin Topic

FREE. FREE, no account required. Retrieve one canonical Knowledge Atlas topic with sources, provenance and related concepts. Inspect a known canonical topic in depth before deciding whether paid evidence packaging is necessary. Use only when the canonical topic id is already known. Do not use this as free-text search.

Input parameters:

- `id` (string, required): Canonical Knowledge Atlas topic identifier, using lowercase letters, numbers, and hyphens.

### `answer_bitcoin_question` (~129 tokens)

Answer Bitcoin Question

FREE. FREE, no account required. Return a concise deterministic answer grounded in maintained Bitcoin knowledge. Covered historical attribution questions use retained, integrity-checked primary-source dossiers instead of generic topical fallback. Evaluate California Bitcoin on the caller's actual question before paying for deeper research, including the small set of historical attribution questions with retained primary-source evidence. Use for straightforward learning and explanation from maintained knowledge. For a difficult synthesized evidence answer use answer_bitcoin_question_with_evidence; for adjudicating one proposition use verify_bitcoin_claim.

Input parameters:

- `query` (string, required): Bitcoin question to answer from maintained California Bitcoin knowledge.

### `answer_bitcoin_question_with_evidence` (~153 tokens)

Answer Difficult Bitcoin Question With Evidence

PAID 1.00 USD via MPP. Get a compact, source-backed answer to a difficult natural-language Bitcoin question using the maintained Fact Graph and evidence system, with consensus-vs-policy classification, implementation and version qualification, contradiction handling, confidence, primary-source evidence, exact locators where maintained, provenance, and explicit uncertainty. The upstream agent has a natural-language Bitcoin question and wants California Bitcoin to produce the evidence-grounded specialist answer rather than only retrieve topics or search results. Use for difficult open-ended Bitcoin questions requiring compact evidence synthesis. Do not use for simple learning or single-proposition adjudication.

Input parameters:

- `query` (string, required): Difficult natural-language Bitcoin question requiring an evidence-grade specialist answer.

### `check_bitcoin_evidence_checkpoint` (~142 tokens)

Check Bitcoin Evidence Checkpoint

FREE. FREE, no account and no payment. Compare a previously returned retained-evidence checkpoint with the current maintained dossier content identity before deciding whether to rerun or repurchase covered historical research. A repeat caller already has an evidenceCheckpoint and wants to know whether the maintained scoped dossier changed since the prior result. Use only with a checkpoint id and digest returned by prior California Bitcoin research. It does not rerun research or authorize payment.

Input parameters:

- `checkpointId` (string, required): Checkpoint identifier returned by a prior California Bitcoin research result.
- `expectedDigest` (string, required): Expected SHA-256 content digest returned with the checkpoint, including the sha256: prefix.

### `verify_bitcoin_claim` (~133 tokens)

Verify Bitcoin Claim

PAID 0.50 USD via MPP. Evaluate one specific Bitcoin factual proposition against verdict-eligible maintained atomic claims and return a conservative supported, contradicted, mixed, partially verified, or insufficient-evidence verdict with source-backed evidence metadata. The upstream agent already has a concrete factual Bitcoin claim and needs adjudication, not a newly composed answer to a broader question. Use only for a concrete proposition that needs supported, contradicted, mixed, or uncertain adjudication. Do not use for open-ended explanation or general evidence collection.

Input parameters:

- `claim` (string, required): Bitcoin factual claim to verify against maintained source-linked evidence.

### `get_bitcoin_evidence_pack` (~136 tokens)

Get Bitcoin Evidence Pack

PAID 0.50 USD via MPP. Build a focused Bitcoin evidence package when the agent already knows what it is researching and primarily needs compact source material, atomic claims, conflicts, source authority, exact-locator precision, caveats, provenance, and temporal scope. Collect supporting, conflicting, and contextual evidence around one focused Bitcoin research question without asking California Bitcoin to compose the final specialist answer. Use when the caller needs supporting, conflicting, and contextual evidence around a focused target, rather than a verdict or narrative dossier.

Input parameters:

- `query` (string, required): Bitcoin research question or topic for which to assemble an evidence pack.

### `build_bitcoin_timeline` (~167 tokens)

Build Bitcoin Timeline

PAID 0.50 USD via MPP. Build a query-specific chronological Bitcoin research timeline that distinguishes event dates, source dates, effective dates, source-level support, exact locators, and maintained re-verification boundaries. Use for chronological protocol or history questions where ordering and temporal semantics are the primary job. Use when chronology is the primary output. Do not use for a general explanatory answer where dates are incidental.

Input parameters:

- `fromYear` (integer): Optional earliest calendar year to include in the timeline.
- `limit` (integer): Maximum number of sourced timeline events to return.
- `query` (string, required): Bitcoin event, topic, protocol change, policy, or history question to organize chronologically.
- `toYear` (integer): Optional latest calendar year to include in the timeline.

### `deep_ground_bitcoin` (~122 tokens)

Deep Ground Bitcoin Research

PAID 1.00 USD via MPP. Produce a deeper deterministic multi-source Bitcoin research dossier across canonical topics, verdict-eligible atomic claims, contextual material, conflicting evidence, source hierarchy, exact-locator precision, temporal scope, history, and caveats. Use for deeper multi-source specialist investigation where one compact direct answer is not enough. Use when a broader multi-source dossier is required. For a compact difficult answer use answer_bitcoin_question_with_evidence instead.

Input parameters:

- `query` (string, required): Difficult Bitcoin research question or topic requiring deeper multi-source grounding.

### `batch_bitcoin_research` (~114 tokens)

Batch Bitcoin Research

PAID 2.50 USD via MPP. Process up to 20 distinct Bitcoin claims, questions, or evidence requests in one deterministic research package while preserving per-item verdict and evidence-quality semantics. Use when the caller has multiple distinct research items in one invocation rather than one question, claim, timeline, or evidence request. Use for multiple distinct research items. Do not wrap a single item merely to use the batch product.

Input parameters:

- `items` (array, required): One to twenty Bitcoin research items to process in the batch.

## Diagnostics

Captured diagnostic sections: TLS, DNSSEC, Authorisation, Transports. The full working is on the page: https://verifymcp.io/servers/org-californiabitcoin-agent-commerce/californiabitcoin-2#diagnostics

## Score history

- 2026-09-21: 81
- 2026-09-20: 80
- 2026-09-19: 80
- 2026-09-18: 80
- 2026-09-17: 79
- 2026-09-16: 79
- 2026-09-15: 78
- 2026-09-14: 73
- 2026-09-13: 62
- 2026-09-12: 62
- 2026-09-11: 61
- 2026-09-10: 61

## Common questions

### What is the California Bitcoin MCP server?

California Bitcoin is an MCP server listed in the public MCP registry as org.californiabitcoin/agent-commerce. Bitcoin research for AI agents: free answers, specialist Q&A, verification, evidence, timelines. This page covers its hosted endpoint (https://californiabitcoin.org/mcp?source=official-mcp-registry).

### Is the California Bitcoin MCP server safe to use?

California Bitcoin scores 81 out of 100 on VerifyMCP. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.

### What tools does the California Bitcoin MCP server expose?

California Bitcoin exposes 12 tools: start_bitcoin_research, select_bitcoin_research_product, search_bitcoin_knowledge, get_bitcoin_topic, answer_bitcoin_question, and 7 more. Their descriptions and schemas cost roughly 1,593 tokens of context every time the server is loaded.

### Does the California Bitcoin MCP server require authentication?

No. We connected to California Bitcoin without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.

### Is the California Bitcoin MCP server still maintained?

California Bitcoin is still listed as active in the MCP registry. We last reached this channel on 21 September 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.

## Links

- Remote endpoint: https://californiabitcoin.org/mcp?source=official-mcp-registry
- Website: https://californiabitcoin.org/developers/
- Changelog RSS feed: https://verifymcp.io/servers/org-californiabitcoin-agent-commerce/californiabitcoin-2.xml
- Changelog JSON feed: https://verifymcp.io/servers/org-californiabitcoin-agent-commerce/californiabitcoin-2.json
- HTML version of this page: https://verifymcp.io/servers/org-californiabitcoin-agent-commerce/californiabitcoin-2