What is HITRAN MCP?
HITRAN MCP, from the GitHub user LKF0402, gives an MCP client 12 tools over HITRANonline, the standard database of molecular spectroscopy used in atmospheric science and gas sensing. The agent looks up molecules and isotopes, fetches line lists for a wavenumber window, lists the strongest lines, computes absorption and transmittance spectra for gas mixtures, plots them, and finds and downloads cross-section files for heavier molecules. A Windows desktop app, HitranLab, shares the same engine.
It is GPL-3.0, written in Python on the official HAPI library, and has about 4 GitHub stars. The repository was created in September 2026 and released v1.6.0 on 8 October 2026. The main README is in Chinese, with a full English version alongside.
How to install HITRAN MCP
git clone https://github.com/LKF0402/hitran-mcp.git && pip install -r hitran-mcp/requirements.txtIs HITRAN MCP worth it?
HITRAN MCP does one specialised job properly: it turns a request like "methane absorption from 2950 to 3100 cm-1 at 296 K and 1 atm" into a calculation on the official HAPI library rather than a number the model recalls. It covers both halves of HITRAN2024, the 61 molecules with line-by-line data and the 600+ heavier species, such as refrigerants and VOCs, that exist only as measured cross-section files. Bridging the two is the useful part; most HAPI scripts stop at line-by-line data.
The physics choices are explicit. Mixtures are computed per species and scaled by mole fraction, line shapes include Voigt, Hartmann-Tran and speed-dependent Voigt, and when temperature, pressure or concentration are missing the tools fill defaults and flag needs_confirm so the agent asks you. Every CSV and PNG carries a provenance watermark naming HITRAN2024, HAPI and the partition-function version, which is what a methods section needs.
The catch: maturity. One developer, 4 stars and releases since September 2026. The MCP layer is a hand-written JSON-RPC server on protocol version 2024-11-05, so newer client features will not appear. HITRANonline puts your API key in the request URL; v1.6.0 added redaction so it no longer reaches error logs, which users often paste when asking for help. Downloads are capped at 300 MB by default, HITRANonline enforces a daily request quota, and the README notes its cross-section API returns HTTP 500 even for valid keys at times.
Our take: for a gas-sensing or atmospheric researcher already on HITRAN, this saves writing the same HAPI glue again, and the provenance stamps make results easy to defend. Check its numbers against a HAPI run of your own before they go in a paper, as its disclaimer asks.
Where it earns its place
An engineer designing a laser methane sensor
Pick an absorption line clear of water interference
Ask the agent for the strongest CH4 and H2O lines in a window with hitran_lines, then a mixed-gas spectrum at the expected concentrations with hitran_spectrum. Free; cached line lists make repeat runs instant.
An atmospheric chemistry master's student
Plot the infrared cross-section of a refrigerant for a thesis figure
Search the cross-section catalogue by name, list files by temperature and pressure, download one with hitran_xsc_download, and plot it with the provenance watermark ready for the caption. Needs a free HITRAN API key.
Before you commit
- Setup
- git clone the repository, pip install -r requirements.txt (Python 3.10+, hitran-api, numpy, matplotlib), then add python <path>/tools/hitran_mcp.py to your client's config as a stdio server. Put a HITRAN API key in HITRAN_API_KEY or tools/hitran_api_key.txt.
- Integrations
- 12 tools over HITRANonline through HAPI 1.3.0.0 and the HITRAN v2 API: species, fetch, lines, spectrum, plot, partition sums (TIPS 2025 to 2011), cross-section search, listing, download and file reading. HitranLab desktop app for Windows x64.
- Data and privacy
- Runs locally; line lists cache in Hitran_Data/ and outputs go to tmp/mcp_out/. Queries reach hitran.org with your API key in the URL path; v1.6.0 redacts it from logs and responses. Results go to your model provider.
- Cost at scale
- Free under GPL-3.0; HITRAN accounts and API keys are free. HITRANonline sets a daily request limit and does not publish the number.
- Limits
- Daily HITRANonline quota returns 403 when exceeded. Cross-section downloads capped at 300 MB per call by default. In-memory spectrum cache holds 200 results.
What’s good
- Line-by-line and cross-section data in one workflow
- Provenance watermark on every CSV and PNG
- Six line shapes including Hartmann-Tran
- Asks for confirmation when T, P or concentration are defaulted
What’s not
- One developer and about 4 stars
- Hand-written server on the 2024-11-05 protocol
- Daily HITRANonline quota and occasional API 500 errors
- Desktop app is Windows only
Best for
Spectroscopists, gas-sensing engineers and atmospheric science students who already use HITRAN and want an agent to fetch data and compute spectra with citations attached.
HITRAN MCP: common questions
- Is HITRAN MCP worth it?
- A careful, well-documented bridge from an agent to HITRAN that a spectroscopist can check line by line, but it is a month-old, one-person project with almost no users yet. We rate it 3.4 out of 5.
- How much does HITRAN MCP cost?
- Free and open source (GPL-3.0). A free HITRAN account and API key are needed for most downloads.
- What are the downsides of HITRAN MCP?
- One developer and about 4 stars; hand-written server on the 2024-11-05 protocol; daily HITRANonline quota and occasional API 500 errors; desktop app is Windows only.
- Who is HITRAN MCP best for?
- Spectroscopists, gas-sensing engineers and atmospheric science students who already use HITRAN and want an agent to fetch data and compute spectra with citations attached.
- How much does HITRAN MCP cost for a team or in production?
- Free under GPL-3.0; HITRAN accounts and API keys are free. HITRANonline sets a daily request limit and does not publish the number.
- Is HITRAN MCP safe for company data?
- Runs locally; line lists cache in Hitran_Data/ and outputs go to tmp/mcp_out/. Queries reach hitran.org with your API key in the URL path; v1.6.0 redacts it from logs and responses. Results go to your model provider.
Answers checked Nov 7, 2026.