Official MCP RegistryListed
GenHTTP Lambda
Write, deploy and host small C# web services and sites at a public address.
First seen 2 Oct 2026. Evidence as of 7 Oct 2026.
24
Tools
From an anonymous probe
1
Source listings
Each with its own history
9
Recorded changes
Since first seen
Tools
| Tool | Description | Behaviour |
|---|---|---|
| change_code | Change some files: add or replace files, remove files, or replace text within a file. Everything not named stays as it is, so there is no need to resend unchanged files. With feature, the change is saved into that feature - the way to work on a lambda that exists: change it as often as you like, deploy: true to try it at the feature's preview address, merge_feature when it is right. Without feature, the newest version is changed and saved as a new version. Update what the change affects in .lambda/docs/ and .lambda/tests/ in the same change - an edit of a passage is enough. check: true compiles without publishing. Code that does not compile is saved but never goes online. | Destructive |
| check_code | Compile without saving or deploying; returns diagnostics with file and line. Does not build the handler, so deploy can still refuse a route whose return type cannot be served. | Read-only |
| create_feature | Start a feature: a place to change a lambda without touching what it has online. It branches off a version - the newest unless base names another - with a copy of its files (its documentation and tests in .lambda/ included) and a copy of the lambda's data, and gets an address of its own to try it at. Change it with change_code or write_code and feature (deploy: true puts it online at its preview address), test it there, and merge_feature once it does what was asked. The lambda goes on serving its visitors from the version online the whole time. | Changes data |
| create_lambda | Create a lambda. Returns its public address and a private editor key, the only way back in. It starts with version 1 - an empty starter, or a copy of a demo. Nothing is online until deploy. | Changes data |
| delete_feature | Throw a feature away: its files, its preview and its copy of the data. The lambda is not touched. For a feature the user does not want after all. | Destructive |
| delete_file | Remove a file, or a folder with its contents, from the workspace - the lambda's data, shared by every version. No deploy or rollback brings it back. With feature, from that feature's copy instead. | Destructive |
| delete_secret | Remove a secret. Code that reads it with Secret.Read fails from its next call on. Only when the user asks for it, or a secret you stored yourself is no longer used. With feature, from that feature's copy instead. | Destructive |
| deploy | Deploy (publish) a saved version so it goes live at its public address - the newest by default. With feature, deploy that feature's files to its own preview address instead, against its copy of the data, leaving the lambda alone. Returns diagnostics on failure, and whatever was online stays online. | Destructive |
| enable_data | Switch on a kind of data the lambda needs and does not have: 'database' (a SQLite database for its records - off until switched on, which makes it, empty), 'secrets' (off until switched on) or 'workspace' (on unless the owner switched it off). Do it when what you build needs it - records need the database, an API key for a service it calls needs secrets. Takes effect at once, without a deploy; switching the database on starts the lambda again on its next request, so its migrations run. There is no tool to switch one off: that deletes what it held, and is the owner's to do in the editor. | Destructive |
| list_demos | Demos this platform keeps online, each a finished lambda showing one way to build something: a REST API over records, registration and login, a websocket game, uploads, live updates. Their keys are public and read only: read the closest one with read_lambda (and list_files, read_logs) before writing similar code. create_lambda with a demo's id as template starts from a copy. | Read-only |
| list_files | The lambda's data: whether its workspace is switched on, and every file in it with size and last write - the same whichever version is online. With feature, that feature's copy of it. The code and assets of a version are in read_lambda. | Read-only |
| list_secrets | The lambda's secrets by name - never their values: whether secrets are switched on, what is stored and when, which names the code reads with Secret.Read and have no value yet (missing) - what the user still has to set - and which it only uses when they are there, checked with Secret.Exists (optional). With feature, that feature's copy. | Read-only |
| merge_feature | Make a feature's files the next version of the lambda, and delete the feature with its preview and its copy of the data - the lambda's own data is not touched. Its .lambda/ becomes the version's documentation and tests, so bring them up to date in the feature first, and run its tests against the preview. Refused while the feature is not based on the newest version (update_feature says how to get it there), and while its code does not compile. deploy: true puts the new version online at once; otherwise deploy it when the user wants it live. | Destructive |
| open_source | Publish a lambda's source code at /source/{publicKey} for anybody to read, star and download as a .NET project, change the license it is published under, or take it down. What is published is the program and what is written about it - every version's code, front end, documentation and tests, and the history of what each changed - never its data: not the database, not the workspace, not a secret's value. Not part of building: only do this when the user asks for it, and ask which license if they did not say (MIT unless they want another). With only privateKey it returns whether it is published. Once published, everything in every version is public, older ones included: keep keys, passwords and personal data out of the files - in secrets and the database. | Destructive |
| platform_guide | How this platform works - read it first: what a version, a feature and data are and how long each lives, the documentation and tests every version keeps beside its program, what the snippet returns, what is imported, what is refused, limits and terms. | Read-only |
| read_database | The lambda's database - its records, shared by every version: whether it is switched on, how full it is, and its tables and views with their columns and how many rows each holds. With table, a page of that table's rows, newest first, up to 100 at a time. Read only: the lambda writes it, through Database.GetConnection(). Use it to see that migrations were applied and records were written. With feature, that feature's copy. | Read-only |
| read_lambda | A lambda's status (online version, newest version, expiry, its tier and what it may use there), its open features, the recent versions with what each was asked for and changed, its data (the database, the workspace and the secrets: whether each is on, what it holds, and which secrets the code reads that have no value yet), and one version - or, with feature, that feature: its documentation (what the app is and why, the technical decisions), how it is tested, its build folder by name with its README, and its files. The documentation comes first and in full up to 20,000 characters; the files come in full when they add up to at most 30,000 characters, otherwise by name and length, with file to read one - a test script or its data too. Read the documentation and the history before changing what you did not write. Also how a demo is read: pass its key from list_demos. | Read-only |
| read_logs | What a deployed lambda has been doing: its recent requests and how they were answered, what it printed, the errors it threw with their stack traces, and how much traffic it has had in the last hour and day. With feature, what that feature's preview has been doing instead, kept apart from the lambda's visitors. Call it after deploying to see that it works, and first when something is reported broken. | Read-only |
| set_secret | Store an API key, password or token under a name the code reads with Secret.Read("NAME") - never put one in the code, an asset, the workspace, a log line or a note. The value is sealed and can never be read back, by you or the owner; only the lambda reads it, from its next call on, without a deploy. Only set a value the user gave you for this: when you do not have it, write the code with Secret.Read and tell the user to set it under Data > Secrets in the editor - read_lambda and list_secrets list what is still missing. Secrets must be switched on first (enable_data). With feature, into that feature's copy (a sandbox key to try it with). Up to 100 secrets of 32 KB each. | Destructive |
| showcase | List a lambda on the public showcase page, change its entry, or take it off. Not part of building: only do this when the user asks for it. With only privateKey it returns the current entry. An entry needs a title, a description and a picture (a screenshot or short GIF of the lambda in use); it is listed while the lambda is online. Write plainly and concretely: what it is and what a visitor can do with it. No marketing language, no superlatives, no exclamation marks, no emoji. | Destructive |
| update_feature | Rename a feature, change what it says about itself, or move its base. merge_feature refuses a feature that is not based on the newest version, since merging it would undo what was saved after it branched off: bring the newer versions' changes into the feature first, then move base to the newest version here. Nothing checks that the changes really are in - that is up to you. | Destructive |
| update_lambda | Change how a lambda's editor opens: view 'Simple' shows the app, how it is doing and a box to ask for a change - for an owner who does not write code - and 'Full' every section, the code, files, data, versions and logs included. Only the default: whoever opens the editor can switch for themselves, and that choice stays theirs. Only do this when the user asks for it. | Destructive |
| upload_file | Write a file to the lambda's workspace - its data, which every version shares and no deploy, rollback or merge touches. With feature, to that feature's copy of the data instead, for trying things out without touching the real one. For files the lambda works with at runtime (pictures people will browse) and large input files that are not program: a model, a dataset, media. Records belong in the database, where the code writes them. Takes effect at once, without a deploy. Not for the front end: pages, scripts and styles are the program and belong in the version as assets (write_code). | Destructive |
| write_code | Save every file, replacing the previous set: as a new version of the lambda, or - with feature - into that feature. .cs files are compiled - lambda.cs returns the handler, others hold types; files under .lambda/ are kept with the version and never compiled or served - docs/product.md, docs/decisions.md, tests/README.md and the tests' scripts and data are what is written about the program, and .lambda/build/ is its build folder, the files you build its assets or code from with a build tool (platform_guide, build); any other file is an asset, served as is and reachable as Assets: the whole front end (pages, scripts, styles, icons) goes here, as part of the program. What the lambda keeps at runtime is data, never files here: records and accounts in the database (a DbContext of Entity Framework Core on Database.GetConnection(), used synchronously; its schema as Evolve migrations shipped here in migrations/), uploads in the workspace - and so is a large input file such as a model or a dataset (upload_file). Send the documentation and tests with the code: written with a new lambda, updated with every change, in proportion to the lambda - a few lines and one quick check for a small one. Say why with specification and change. deploy: true publishes in the same call - a version at the public address, a feature at its preview address. To send only what changes, use change_code. To change a lambda that is already in use, work in a feature. | Destructive |
Change history
- write_code: input schema changed
- write_code: description changed (+"kept with" +"version and never compiled or served" +"are what is written about the program, and .lambda/build/ is its build folder,")
- read_lambda: input schema changed
- read_lambda: description changed (+"its build folder by name with its README,")
- check_code: input schema changed
- change_code: input schema changed
- server instructions changed (+"What you build the assets or code from with a build tool goes in .lambda/build/ (build/ in a clone), built by you and saved with what it built - nothing is built here: platform_guide, build.")
- server instructions changed (+"If you can run git, clone the lambda instead (read_lambda's gitUrl) - AGENTS.md in it says how: a commit pushed to main is a version, a branch pushed is a feature - platform_guide, git.")
- server instructions changed (+"Never poll for changes (fetch on a timer to refresh a page): push them from the server with server-sent events (demo-live) or a websocket (demo-game) - platform_guide, liveUpdates. We ask for a small "Made with GenHTTP Lambda" line at the foot of the pages you build - a link, plain text on a domain of its own - unless the user does not want it: platform_guide, backlink.")
| Source | Listing | First seen | Last seen | Versions |
|---|---|---|---|---|
| Official MCP Registry | dev.genhttp/lambda | 2 Oct 2026 | 7 Oct 2026 | 1 |