| 1 | import { Container, type StopParams } from "@cloudflare/containers"; |
| 2 | import { WorkerEntrypoint } from "cloudflare:workers"; |
| 3 | |
| 4 | import { |
| 5 | type AgentModel, |
| 6 | type Issue, |
| 7 | type Pull, |
| 8 | type RepoPath, |
| 9 | type Result, |
| 10 | type RunHostedInput, |
| 11 | type RunnerApi, |
| 12 | type ServiceBinding, |
| 13 | type User, |
| 14 | type Viewer, |
| 15 | fail, |
| 16 | identityClient, |
| 17 | ok, |
| 18 | workClient, |
| 19 | } from "@g1t/contracts"; |
| 20 | |
| 21 | export interface RunnerEnv { |
| 22 | SANDBOX: DurableObjectNamespace<AttemptSandbox>; |
| 23 | IDENTITY: ServiceBinding; |
| 24 | WORK: ServiceBinding; |
| 25 | /** Secret. The model key the hosted agent runs on. */ |
| 26 | ANTHROPIC_API_KEY?: string; |
| 27 | /** |
| 28 | * Comma-separated usernames allowed to start hosted agents. Runs spend the |
| 29 | * key above, so this stays an allowlist until accounts bring their own. |
| 30 | */ |
| 31 | HOSTED_AGENT_USERS: string; |
| 32 | /** |
| 33 | * The models offered, as JSON: |
| 34 | * `[{ id, label, description, modelName, model }]`. `modelName` is what |
| 35 | * people see; `model` is the identifier sent to the provider. |
| 36 | */ |
| 37 | AGENT_MODELS: string; |
| 38 | /** |
| 39 | * A Cloudflare AI Gateway id. When set, model traffic goes through that |
| 40 | * gateway, which is where logging, spend limits, caching and fallback |
| 41 | * between providers are configured. Empty sends it to the provider |
| 42 | * directly. |
| 43 | */ |
| 44 | AI_GATEWAY_ID: string; |
| 45 | CLOUDFLARE_ACCOUNT_ID: string; |
| 46 | /** Secret. Needed only if the gateway requires authentication. */ |
| 47 | AI_GATEWAY_TOKEN?: string; |
| 48 | } |
| 49 | |
| 50 | const MAX_AGENTS_PER_RUN = 5; |
| 51 | /** A run that takes longer than this has its token expire under it. */ |
| 52 | const TOKEN_TTL_SECONDS = 2 * 60 * 60; |
| 53 | /** How g1t's own agent is labelled. What runs behind it is g1t's choice. */ |
| 54 | const AGENT = "g1t-agent"; |
| 55 | |
| 56 | /** Which pull request a sandbox is working on, and as whom. */ |
| 57 | type Run = { actor: User; repo: RepoPath; number: number }; |
| 58 | type RunRequest = Run & { envVars: Record<string, string> }; |
| 59 | |
| 60 | /** |
| 61 | * One sandbox, for one pull request. The image's entrypoint is the g1t runner, |
| 62 | * which does the work and exits; this class only starts it and cleans up |
| 63 | * if it dies without reporting. |
| 64 | */ |
| 65 | export class AttemptSandbox extends Container<RunnerEnv> { |
| 66 | sleepAfter = "45m"; |
| 67 | |
| 68 | async run(request: RunRequest): Promise<void> { |
| 69 | const { envVars, ...run } = request; |
| 70 | await this.ctx.storage.put("run", run); |
| 71 | await this.start({ envVars, enableInternet: true }); |
| 72 | } |
| 73 | |
| 74 | override async onStop({ exitCode }: StopParams): Promise<void> { |
| 75 | if (exitCode === 0) return; |
| 76 | // The runner closes its own pull request when it fails. This covers a |
| 77 | // sandbox that was killed before it could; closing twice is refused |
| 78 | // harmlessly. |
| 79 | const run = await this.ctx.storage.get<Run>("run"); |
| 80 | if (run) await workClient(this.env.WORK).closePull(run.actor, run.repo, run.number); |
| 81 | } |
| 82 | } |
| 83 | |
| 84 | type ConfiguredModel = AgentModel & { model: string }; |
| 85 | |
| 86 | /** Where the sandbox sends model requests, and what it sends with them. */ |
| 87 | function modelEnv(env: RunnerEnv, model: ConfiguredModel): Record<string, string> { |
| 88 | const vars: Record<string, string> = { |
| 89 | ANTHROPIC_API_KEY: env.ANTHROPIC_API_KEY!, |
| 90 | ANTHROPIC_MODEL: model.model, |
| 91 | // Recorded at the top of the session, so anyone can see what ran. |
| 92 | AGENT_MODEL_NAME: `${model.modelName} (${model.label})`, |
| 93 | }; |
| 94 | if (env.AI_GATEWAY_ID) { |
| 95 | vars.ANTHROPIC_BASE_URL = `https://gateway.ai.cloudflare.com/v1/${env.CLOUDFLARE_ACCOUNT_ID}/${env.AI_GATEWAY_ID}/anthropic`; |
| 96 | if (env.AI_GATEWAY_TOKEN) { |
| 97 | vars.AI_GATEWAY_TOKEN = env.AI_GATEWAY_TOKEN; |
| 98 | vars.ANTHROPIC_CUSTOM_HEADERS = `cf-aig-authorization: Bearer ${env.AI_GATEWAY_TOKEN}`; |
| 99 | } |
| 100 | } |
| 101 | return vars; |
| 102 | } |
| 103 | |
| 104 | function buildPrompt(issue: Issue, instructions: string): string { |
| 105 | const parts = [ |
| 106 | "You are a coding agent working in the git repository checked out in the current directory.", |
| 107 | `Issue #${issue.number}: ${issue.title}`, |
| 108 | issue.body, |
| 109 | ]; |
| 110 | if (issue.checks.length > 0) { |
| 111 | parts.push( |
| 112 | `These commands must pass when you are done. Run them if the tools are installed:\n${issue.checks.map((check) => `- ${check}`).join("\n")}`, |
| 113 | ); |
| 114 | } |
| 115 | if (instructions) parts.push(instructions); |
| 116 | parts.push( |
| 117 | "Make the change and keep it focused on the issue. Commit your work with a clear message. Do not push; that is done for you. Finish with a short summary of what you changed and why.", |
| 118 | ); |
| 119 | return parts.filter(Boolean).join("\n\n"); |
| 120 | } |
| 121 | |
| 122 | export default class RunnerService |
| 123 | extends WorkerEntrypoint<RunnerEnv> |
| 124 | implements RunnerApi |
| 125 | { |
| 126 | /** A Worker must have an event handler; this service is RPC-only. */ |
| 127 | fetch(): Response { |
| 128 | return new Response("Not found\n", { status: 404 }); |
| 129 | } |
| 130 | |
| 131 | private configuredModels(): ConfiguredModel[] { |
| 132 | return JSON.parse(this.env.AGENT_MODELS); |
| 133 | } |
| 134 | |
| 135 | private allowed(viewer: Viewer): boolean { |
| 136 | if (!viewer || !this.env.ANTHROPIC_API_KEY) return false; |
| 137 | return this.env.HOSTED_AGENT_USERS.split(",") |
| 138 | .map((name) => name.trim()) |
| 139 | .includes(viewer.username); |
| 140 | } |
| 141 | |
| 142 | async models(viewer: Viewer): Promise<AgentModel[]> { |
| 143 | if (!this.allowed(viewer)) return []; |
| 144 | return this.configuredModels().map(({ id, label, description, modelName }) => ({ |
| 145 | id, |
| 146 | label, |
| 147 | description, |
| 148 | modelName, |
| 149 | })); |
| 150 | } |
| 151 | |
| 152 | async run( |
| 153 | actor: User, |
| 154 | repo: RepoPath, |
| 155 | issueNumber: number, |
| 156 | input: RunHostedInput, |
| 157 | ): Promise<Result<Pull[]>> { |
| 158 | if (!this.allowed(actor)) { |
| 159 | return fail("forbidden", "g1t agents are not enabled for your account."); |
| 160 | } |
| 161 | const models = this.configuredModels(); |
| 162 | const model = input.model |
| 163 | ? models.find((candidate) => candidate.id === input.model) |
| 164 | : models[0]; |
| 165 | if (!model) return fail("invalid", "That model is not available."); |
| 166 | const count = Math.min(Math.max(Math.trunc(input.count) || 1, 1), MAX_AGENTS_PER_RUN); |
| 167 | const identity = identityClient(this.env.IDENTITY); |
| 168 | const work = workClient(this.env.WORK); |
| 169 | |
| 170 | const found = await work.getIssue(repo, issueNumber, actor); |
| 171 | if (!found.ok) return found; |
| 172 | const { issue } = found.value; |
| 173 | const prompt = buildPrompt(issue, input.instructions?.trim() ?? ""); |
| 174 | |
| 175 | const pulls: Pull[] = []; |
| 176 | for (let i = 0; i < count; i++) { |
| 177 | const opened = await work.openPull(actor, repo, { |
| 178 | issue: issue.number, |
| 179 | agent: AGENT, |
| 180 | runtime: "hosted", |
| 181 | }); |
| 182 | // The first failure is the answer; later ones mean some already run. |
| 183 | if (!opened.ok) return pulls.length ? ok(pulls) : opened; |
| 184 | const pull = opened.value; |
| 185 | // Opened without a branch, so it has a fork. |
| 186 | const fork = pull.fork!; |
| 187 | pulls.push(pull); |
| 188 | |
| 189 | // The sandbox acts as the person who started it, through a token |
| 190 | // that only lives as long as a run can. |
| 191 | const { token } = await identity.createAccessToken( |
| 192 | actor, |
| 193 | `g1t agent on ${repo.namespace}/${repo.name}#${pull.number}`, |
| 194 | TOKEN_TTL_SECONDS, |
| 195 | ); |
| 196 | const sandbox = this.env.SANDBOX.get(this.env.SANDBOX.idFromName(pull.id)); |
| 197 | await sandbox.run({ |
| 198 | actor, |
| 199 | repo, |
| 200 | number: pull.number, |
| 201 | envVars: { |
| 202 | G1T_API: "https://api.g1t.sh", |
| 203 | G1T_TOKEN: token, |
| 204 | G1T_USER: actor.username, |
| 205 | G1T_REPO: `${repo.namespace}/${repo.name}`, |
| 206 | PULL_NUMBER: String(pull.number), |
| 207 | GIT_REMOTE: `https://g1t.sh/${fork.namespace}/${fork.name}.git`, |
| 208 | COMMIT_MESSAGE: issue.title, |
| 209 | PROMPT: prompt, |
| 210 | ...modelEnv(this.env, model), |
| 211 | }, |
| 212 | }); |
| 213 | } |
| 214 | return ok(pulls); |
| 215 | } |
| 216 | } |